(introduction...)

Prepared in collaboration with Institute for Ecology of Industrial Areas (IEIA)

IETC - International Environmental Technology Centre

International national Environmental Technology Centre, United Nations Environment Programme and Water Branch, United Nations Environment Programme. 1998

Disclaimer:

Mention of technologies, processes, products, equipment, instruments or materials identified in this Source Book of Alternative Technologies for Freshwater Augmentation does not imply recommendation or endorsement by the United Nations Environment Programme (UNEP), its International Environmental Technology Centre (IETC), or its Water Branch, nor does it imply that these are necessarily the best available for the purpose The opinions and views expressed in the document do not necessarily state or represent those of UNEP, the IETC or the Water Branch.

IETC Technical Publication Series Issue 8
ISBN 92-807-1508-8C

Foreword

The countries of Eastern and Central Europe have seen growing pressure on water resources, with increasing demand and costs, for agricultural, domestic and industrial consumption. This has brought about the need to maximize and augment the use of existing or unexploited sources of freshwater. There are many modern and traditional alternative technologies for improving the utility and augmenting the supply of water being employed in various countries, but with limited application elsewhere due to the lack of information transfer among water resources managers and planners.

The "Source Book of Alternative Technologies for Freshwater Augmentation in Eastern and Central Europe" was prepared by the Institute for Ecology of Industrial Areas (IETU) as part of the joint United Nations Environment Programme (UNEP) Water Branch and International Environmental Technology Centre (IETC) initiative to provide water resource managers and planners, especially in developing countries and in countries with economies in transition, with information on the range of technologies that have been developed and used in the various countries throughout the world. UNEP wishes to thank the Institute for Ecology of Industrial Areas and those individuals involved in the preparation of this Source Book. This Source Book was compiled by Prof. R. Janikowski. The final revision of the Source Book was assisted by V. Santiago, C. Strohmann, and E. Khaka from UNEP IETC and Water Branch, respectively.

This information was gathered through surveys carried out on a regional basis-in Africa, Western Asia, East and Central Europe, Latin America and the Caribbean, and Small Island Developing States. The results, including this Source Book, will be compiled into a Global Source Book on Alternative Technologies for Freshwater Augmentation to be used throughout the countries of the world.

It is hoped that the technologies summarized here will be useful in the sustainable development of the countries of Eastern and Central Europe and other regions.

John Whitelaw
Director
International Environmental Technology
Centre
United Nations Environment Programme

Terttu Melvasalo
Director
Water Branch
United Nations Environment Programme

1. Background

Effective reduction of global environmental impacts requires both a clear, integrated, and holistic understanding of the economic and societal that govern such impacts, and the appropriate technologies and instruments of environmental policy that can be applied to mitigate such impacts. In this regard, there is widespread recognition that the management of freshwater resources must be among the highest priorities of business, government, community organizations, and individual households. Nowhere is this recognition more clearly stated than in the milestone, 1987 report, "Our Common Future", by the World Commission on Environment and Development (the Brundtland Commission), and its successor, "Agenda 21" agreed at the United Nations Conference on Environment and Development (the Rio Conference). These documents emphasized the importance of alternative and unconventional technologies for augmenting water resources in the pursuit of sustainable development. Maximizing the efficiency of use of existing freshwater resources, and augmenting existing sources of water, are vitally important aspects of sustainable development which involve meeting the needs of the present without compromising the ability of future generations to meet their needs. Economic growth provides the conditions through which protection of the environment can best be achieved, and balanced with other human goals, provides that such development be sustainable.

At present, Eastern and Central European countries are undergoing a process of transition from centrally-planned to market economies. This presents an opportunity to change the basis upon which environmental impacts are accounted for in the economies of these countries. At the same time, the technological changes in the industrial, rural, and municipal sectors present an opportunity to introduce more effective (efficient) means of reducing environmental impacts within the sectors that have traditionally created the greatest degree of environmental impact. While the scale and nature of environmental problems varies in the different subregions of Eastern and Central Europe, most problems are of common origin.

Eastern and Central Europe, with few exceptions, is a well-watered region of Europe, with many rivers and lakes, although relatively few are sizable lakes. Because urbanization and industrial development occurred in the formerly centrally-planned economies without proper measures for environmental protection and sound water management, the state of environment declined, with numerous instances of environmental pollution, water resource depletion, and creation of threats to subsequent development. The lack of efficient technologies of production contributed to high rates of water consumption, especially in power generation, mining, and steel industries. The resultant degradation of surface water quality forced authorities to switch to the extensive use of groundwater, overuse of which for industrial purposes lowered the table of water and caused wells to dry up. In many locations, the surfacial aquifers (water-bearing layers) were completely destroyed or contaminated, forcing many users to exploit progressively deeper ones. While such artificial water shortages are especially characteristic of areas with large industrial water demands and surface mining activities, their impact has extended into many rural areas, where there is an urgent need to install or replace water supply systems.

In some parts of the region, contamination of the drinking water supply is a serious problem. For instance, overuse and contamination by sewage has stressed the piped water supply system in Tirana, Albania, and has resulted in gastrointestinal infections and outbreaks of diarrhoea, dysentery, and hepatitis. In September 1994, the first case with cholera since 1914 was diagnosed after two deaths due to dehydration. Other cases of cholera were observed in Berat, Kucove, Elbasan, Lushnje, Lezhe, and Fier, as well as in Peshkopi, Kruje, and Kurbin. While this epidemic situation was stabilized by the end of November 1994 at the beginning of winter, a further 15 of the 17 persons who had been hospitalized in the Psychiatric Hospital at Elbasan died of this disease.

Throughout the region, technological development has led to the abandonment of traditional practices of water management, such as rainwater harvesting. Furthermore, because these technological developments provided an abundance of water without charge to the consumers, and without regard to the protection of the water resources from which the water was abstracted, many people used water carelessly. As a result of the lack of regard for the environment, many mistakes in catchment area management were made. For example, excessive river beds regulation through construction of numerous weirs, diversions and dams resulted in the drying of bogs, ponds, and small lakes, all of which are essential elements within a watershed and contribute to sustainable water supplies. Hence, while such developments provided abundant water in the short term, the environmental damage that occurred crucially depleted renewable water resources in the longer term. In addition, industrialization, urbanization, and the development of polluting transportation systems over the years discharged high pollutant loads to aquatic ecosystems, their catchment areas, and the surface and ground water system. In many regions, especially those dependent on surface water sources for their water supply, and usually located along the upstream portions of large European rivers such as the Vistula, Oder, Danube, and Dnieper, these actions of the past have created water shortages due to water quality problems as a result of contamination of these rivers with toxic pollutants. Eutrophication, or the enrichment of waterbodies with plant nutrients, likewise is a common problem in Eastern and Central European countries, primarily due to inappropriate infrastructure and poorly functioning communal wastewater treatment facilities which allow large quantities of biogenic materials to enter natural waterbodies. This process is exacerbated by intensive and widespread use of fertilizers in agricultural practices.

Traditionally, governments have responded to the additional water demand created by such artificial shortages by increasing the water supply. However, in many Eastern and Central European locations, this practice is no longer an easy task because of the diminishing of water resources. With depleting water resources and increasing costs of supply, there is a need to maximize the use of existing water and to make use of hitherto unexploited water resources. There are numerous techniques, modern and traditional, for maximizing and augmenting water resources, practised in different parts of the world, and similar techniques for minimizing water use both in industry and in the community. These include wastewater reuse, water recycling, desalination, wastewater treatment, and rainwater harvesting. In Eastern and Central Europe, these techniques also include implementation of technologies that enhance water economy, purify contaminated water, better manage water distribution systems, stimulate proper consumer habits to reduce household water use, preserve and protect catchment areas, and augment retention. While some of these technologies can be, and have been, applied in other regions, their application in Eastern and Central Europe has been often limited by lack of information on the techniques that are feasible and which techniques are available.

Because such limitations are widespread, the United Nations Conference on Environment and Development, in Chapter 34 of Agenda 21, called for the transfer environmentally sound technology, through cooperation and capacity building between countries, and identified improved access to information on environmentally sound technologies as one of the priorities to facilitate technology transfer to developing countries and countries with economies in transition. Likewise, Chapter 18 of Agenda 21 encouraged the utilization of appropriate technology in water supply and sanitation. In combination, the primary objective of Agenda 21 is to improve access to technical information so as to enable countries in transition to make informed choices, leading to the use of appropriate technology for their specific situations.

Sustainable development can be promoted by policies designed to encourage development, deployment, and, when appropriate, distribution or transfer of technologies which are intended to reduce, to a justifiable minimum, the use of energy and raw materials, and the creation of wastes and release of contaminants to the environment, in order to produce the goods and services demanded by society. To help water resources managers and planners around the world, and especially in developing countries and countries with economies in transition, improve their environmental performance, the United Nations Environment Programme (UNEP), through its Water Branch and International Environmental Technology Centre (IETC), established a task force to create this Source Book of Alternative Technologies for Freshwater Argumentation in Eastern and Central Europe. The main objective in the preparation of this Source Book was to compile a thorough inventory of available technologies for maximizing the use and augmenting the existing freshwater resources in Eastern and Central Europe. As a result of this practical focus, information on the capital as well as the operation and maintenance costs, ease operation, and suitability of the technologies is also included, and case studies of innovative and cost effective technologies are documented. The technologies identified in this Source Book include alternative technologies that both maximize the efficiency of use of existing freshwater resources and/or augment existing supplies by drawing on unconventional sources of water. It is intended to be a reference manual, presented in a user-friendly format, which contains the information needed to implement a programme of sustainable water resources management. It is specifically designed to assist water resource managers and planners in fulfilling their commitment to environmental stewardship in a comprehensive fashion, but will be of interest and value to environmentalists in general and to all those concerned with water management.

This Source Book is one of five regional guides, the contents of which will be compiled into a global handbook which includes Eastern and Central Europe, Latin America and the Caribbean, Asia and the Pacific, Africa, and Small Island Developing States. While each of these regional Source Books will encourage sharing of technologies and experiences within particular geographical regions, the comprehensive Source Book will encourage information and technology transfer between major regions of the globe.

2. Definitions

In this Source Book, technology is broadly defined, including technologies that range from the reintroduction of beaver to the use of water-saving products and ecological information campaigns. While a more narrow definition of technology limits the use of the term to the use of technological equipment, in the sense of machinery, it fails to perceive or include the sense of relationship between nature and society as being affected by the technology and ignores the greater framework within which the technology is developed and selected. Technology, in the broadest sense, encompasses both its forms (as knowledge and know-how, or as embodied in equipment and products) and use as a key factor in all human activities and walks of life. Technologies that maximize the efficiency of use of existing freshwater resources or augment existing sources of water, in this broader sense, are a vitally important element of development in all countries. However, such technologies are especially important in Eastern and Central European countries because, during the era of ideological and economic domination by the Soviet Union in this region, urbanization and industrial development were performed without regard for the proper measures of water management that this broader definition of technology implies.

3. Methodology

Based upon the river systems within the region (see Box), field surveys and detailed inventories of available technologies for maximizing the use and augmenting the availability of existing freshwater resources were carried out in the three principle watersheds, covering the six major subregions, of Eastern and Central Europe; namely, the Baltic Sea basin which includes Latvia and Poland, the Black and Caspian Seas basin which includes Ukraine, Romania, and Hungary, and the Mediterranean Sea basin which includes Albania. The procedure for selecting alternative technologies for freshwater augmentation for inclusion in this regional Source Book was oriented toward technologies that promote sustainable development, and involved an intensive literature survey of methods used to maximize and augment freshwater resources for all human purposes, including agriculture, industry, and domestic or potable use. This survey included wastewater treatment and reuse, water recycling, rainwater harvesting, water savings and storage, as well as "soft" methods for the minimization of water use (e.g., promotion and use of good housekeeping practices, water saving products, educational campaigns, etc.), and encompassed both modern and traditional methods.

A very important source of information used in this study was some registers and guide books that contain descriptions of over 200 technologies; for instance, the Polish Guide-book About The Water Protection Facilities And Services and the Investors' Environmental Guidelines, developed in Ukraine, proved to be excellent resources. It is also important to note that, while every effort has been made to provide accurate information about the costs of the identified technologies, the cost information presented should be treated as indicative only due to inflation, which may be significant in the countries of Eastern and Central Europe, and conversion from the original units (Polish zloty, Latvian lats, Hungarian forint, etc.) to United States dollars.

The river systems of the region may be divided into four geographic groups; namely, the basins that drain west and north into the Baltic Sea, those that drain south into the Mediterranean Sea, those that drain east and southeast into the Black and Caspian Seas, and those that drain north into the Arctic Sea. The Volga River is the region's, and continent's, longest river (3 529 km) and has the largest drainage basin (1 359 750 km²). Other major rivers are the Danube (the second longest river of Europe), Dnieper, Don, Vistula, and Oder. Many of the major rivers of the region serve as transportation routes and are interconnected by networks of canals. Three major climate types can be distinguished in the region; namely, the transitional climate with 500 to 1 000 mm of annual rainfall, cold winters, and warm summers; the continental climate of the northeast with 250 to 500 mm of annual rainfall, long and cold winters, and hot summers; and, the Mediterranean climate with moderate rainfalls of 250 to 1 000 mm, mild and wet winters, and hot and dry summers.

Three different case studies on the successful application of local technologies for maximizing the efficiency of use of water resources and for freshwater augmentation were identified, including beaver reintroduction, the Vija-biotechnology system of wastewater treatment, and the ecological education campaign "Washing may be Cheaper". However, this survey did not include information about clean technologies which may be used in industry to save water and minimize generation of wastewater.

4. Results of the survey

Progress in the sustainable development of the region is slow and the introduction of new technologies and economic instruments is not as rapid as the decrease in energy and natural resources usage related to economic decline and recession. These latter economic factors have resulted in a decrease in water use, water losses, and water pollution that of sufficient magnitude to reduce overall consumption to sustainable levels. Thus, the main task is to maintain this level of use until at least the year 2000.

The major causes of water losses in the region include widespread use of potable water (both by households and industry) in inappropriate ways (e.g., about one-half of the 4.3 km³ of drinking water consumed annually in Ukrainian cities is used for non-food needs); leakage during transmission through water mains and losses in the water supply systems; user-related losses and waste (amounting to more than 20% of the potable water delivered to households, and 20% to 30% of the potable water delivered to industry); lack of an economic regulatory mechanism to promote the rational use of limited water resources; poor quality of fixtures, fittings, and pipes; shortages of flow-metering equipment, both in households and in industry (to measure water and wastewater volumes); and, shortages of pressure stabilization devices in the water delivery and distribution systems (both system and terminal pressure stabilizers and regulators).

The major causes of water wastage in industry include use of drinking quality water from municipal water supplies in the production processes, where technical quality water would be adequate and is available in sufficient quantities; lack of coordination by regional authorities to promote more efficient usage of water by industrial facilities; use of direct flow-through cooling equipment; lack of water recycling; discharge of relatively pure industrial water as effluent into the sewerage system; widespread lack of water reuse, such as the use of counter-flow cascade washing technology in the electroplating process and the use gun-type nozzles on industrial sites for washing vehicles, equipment, and premises; lack of economic incentives for workers, engineers, and maintenance personnel to promote the rational use and conservation of drinking water; poor maintenance of on-site water supplies (e.g., absence of regular pipe cleaning to ensure maximal mains capacity, pressure regulation, preventive repair, etc.); and, lack of the reserve accumulation ponds which collect water at night to smooth peak water demand during the day in some large cities, which is especially noticeable during summer water shortages.

It is paradoxical that one of the largest sources of "new" water in the region is the water-pipe networks themselves. In the other words, the detection and minimization of leaks is an extremely important method of freshwater augmentation in the region. For example, in Tirana, where the production of water by the waterworks during 1994 was 54.6 million m³, the total volume of water sold totalled only 21.4 million m³, which implies a loss of the water during transmission of 23.2 million m³, or 61%, of production. Annual transmission losses in Ukraine reach about 0.3 km³, or more than 8% of the municipal water supply. In industry, transmission losses reach 18% to 30% of water drawn from municipal water supplies. In Poland, estimated total water losses in water-pipe networks in selected towns amount to 8 000 m³/year/km of network, or, for cities with less than 100 000 inhabitants, to 40 dm³/capita/day of water, and, for cities over 100 000 inhabitants, to 100 dm³/capita/day of water. In Latvia, the City of Riga, which has a water supply network extending over 960 km, must renew at least 70 km of the network which are in a very poor condition. The situation is similar in the other cities of Latvia. It should be noted that the oldest networks, built during the four decades from the beginning of the century to about 1940, are in good condition, with few exceptions. These systems were constructed of 300 mm to 800 mm diameter cast iron pipes with an anticipated lifespan of 50 to 90 years. In contrast, the more recent networks, built between 1940 and 1990 with pipes made in Russia are in poor condition. The main reasons for the failure of the more recent networks include us of a limited selection of materials and lack of internal anti-corrosion coatings; poor quality piping; poor construction of, and foundations under, the pipes; damage to joints and connections; insufficient external corrosion protection (cathode defence); and, generally poor maintenance.

The introduction of water meters in the region has provided the impetus to develop new, water saving technologies and maintain the existing ones effectively. Because it is well known that transmission leaks occur in direct proportion to the pressure in water supply and distribution networks, one of the best ways to decrease the numbers of leaks in large municipal or industrial water supply networks is to optimize and reduce or stabilize operating pressures. Reduction of operating pressure variations in the Ukrainian water supply networks could conserve up to 100 million m³/year of drinking water. This saving could be increased further through the development and introduction of new, low flow-low pressure pipe fixtures and fittings, pressure regulators and stabilizers, pipes, and controlled drive pumps, and, additionally, by the use of ultrasound and electronic diagnostic systems within the network to monitor network conditions and locate and isolate leaks or damages for repair.

Table 1 presents a summary of the results of the survey of technologies in the region, and a brief description of each. Detailed information on each of technologies is presented in Part B. Alternative Technologies. These technologies, however, are only a few examples of environmental friendly solutions for maximizing use and augmenting existing freshwater resources. Nowadays it is indispensable to provide a cost effective, efficient solution for water management.

New direction appeared in the region in the waste water treatment. It is the use of cost effective, renewable natural processes (LEMNA technology, wetlands, ponds, etc.). They are simple, with no need of energy supply, reliable. The government have to support the construction of adequate treatment facilities and moreover the preventive techniques, because environmental protection is far behind economical interests. It is necessary to provide soft loans, subventions, tax reductions. And of course the entrepreneurs, companies, plant operators should change their attitudes with environmental protection like in developed countries.

Most technologies can be recommended for application anywhere in the region without restraints. But usage of some technologies especially based on ecological solutions e.g. hydrobotanical treatment are more efficient in countries with milder climatic conditions.

Implementation of new, best available technologies is very limited according to limited possibilities of financing from enterprises and municipalities and from State budget too. Therefore the high level demands can be addressed only to the new activities of greatest municipal or private projects, but existing activities or enterprises has not possibilities to choose the best available technology and often are working on available technology.

A new system of planning and promotion for urban water supply development should be developed. It is also necessary to develop "The general scheme for drinking water conservation" that is to reflect the strategy of water resource use in short-term and in long-term perspective (up to 25-50 years). In future it would be advisable to prohibit the use of drinking water for industrial needs, in cases there are resources of purified wastewater or unconventional water supply sources. The prohibition is of prime importance with respect the processes, that consume water irretrievably. In other words it is extremely important to develop a fully free market of water with appropriate economic, legal, and informative instruments in all over the East and Central Europe countries. However, it is a need to create new ethic for sustainable living and to translate its principles into practice within educational ecological campaigns for both, the whole of society and specialists, to augment the resources of water.

Humanity must live within the carrying capacity of the Earth. There is no other rational option in the longer term. We must use the resources of the Earth sustainably, prudently and with full harmony with nature and augment water resources above all by strengtening global as the same as local ecosystem capacity with ecological measures - for instance by beaver reintroduction and by efficient and wiser use of it.

TABLE 1. Summary of Alternative Technologies Presented in the Source Book.

Technology	Short Description of Technology	Extent of Use	Capital Costs	Operation and Maintenance Costs	Effectiveness of the Technology	Suitability	Advantages	Disadvantages
Water conservation and saving
Ecological education campaign	Uses consumer behaviour for environmental benefit.	Rare	Low	Low	High	Widespread, but especially in urban areas	Economic	None known
Environmental labelling	Use of labels to identify "safe" products, including water saving products.	Rare	Low	Moderate	Moderate	Widespread, but especially in urban areas	Economic	None known
Water-saving closets	The reduction of the flushing - water volume by using special fittings.	Rare	Moderate	Low	Moderate	Widespread	Economic	None known
Water-saving shower facilities	Uses plumbing fixtures to reduce water consumption in shower facilities	Rare	Moderate	Low	Moderate	Widespread	Economic	None known
Cold and hot water meters	Water meters relate consumer costs to real consumption of water.	Moderate	Low	Low	High	Widespread	Economic	None known
TV inspections	Records the technical state of sewage systems.	Moderate	Moderate	Moderate	High	Widespread	User friendly Computer compatible	Skilled technicians required
Non-invasive renewal (enlarging) of drain pipes	Introduction of new pipes of the same or larger diameter.	Rare	High	High	High	Widespread	Environment-friendly	None known
Non-invasive renovation and tightening of pipes	Introduction of liners or sealants to renovate pipes and stop leaks.	Rare	Moderate	High	High	Widespread	Environment-friendly	None known
Computer modelling for freshwater supply system management (OPUS)	Optimizes supply system using graph theory-based computer program	Rare	Low	High	Very high	Widespread	Reduces ineffective distribution	Lacks well-documented information
Rationalization of washing powder dosages	Determines dosage of washing powder according to hardness of water.	Moderate	Low	Low	Moderate	Widespread	Economic Social	None known
Lining of solid waste disposal sites	Protects water resources from contamination from waste disposal sites.	Moderate	High	Low	High	Waste disposal sites	Protects groundwater resources	None known
Water recycling in galvanic technology	Use of closed water cycles in plating and metallurgical processes.	Rare	High	High	High	Metals industry	Cost saving on chemical agents	Sophisticated technology
Recycling of wastewater from a bus transport company	Allows reuse oily wastewater at bus stations.	Rare	Moderate	Low	High	Transportation industry	Simplicity	Sludge disposal required
PURATOR recycling system for car washes	Recycles water used at new petrol stations.	Moderate	High	Low	High	Widespread	A clean technology	None known
Water recycling in thermoelectric power plants	Treats and recycles cooling, process, and wash water.	Rare	Moderate	Low	Moderate	Power generation industry	Prevents thermal pollution	None known
Drip-irrigation system	Water-saving irrigation system.	Moderate	Moderate	Moderate	High	Agriculture	Economic	Reduces over-irrigation
NETAFIM drip irrigation system	Water-saving irrigation system for high value edible and ornamental plants.	Rare	High	Moderate	Very high	Agriculture	Economic	Reduces over-irrigation
Wastewater treatment and water reuse
Biotechnology-based wastewater treatment	Biological wastewater treatment using hydrobionts.	Moderate	Moderate	Moderate	High	Widespread	Wide range of applications	None known
Ozone/electro-plasma wastewater treatment	Electro-plasma wastewater treatment.	Moderate	High	Moderate	Very High	Widespread	Economic	Highly sophisticated technology
Denitrification treatment for wastewaters contaminated with NH4, NO3 and NH3	Wastewater treatment using biological denitrification and thermal decomposition.	Rare	Very high	High	High	Industry	Reduced nitrogen loadings	None known
Treatment of coking plant wastewater using polyelectrolyte pre-treatment	Wastewater treatment using cationic polyelectrolytes for cyanide removal.	Rare	Very high	High	High	Industry	Reduced heavy metal loads	None known
Treatment of food industry wastewater using polyelectrolytes	Wastewater purification using precipitation, coagulation-flocculation, and polyelectrolyte treatment.	Rare	High	Moderate	Moderate	Food processing industry	Recovery of fatty materials	None known
Slaughter house wastewater purification	Purification of organic wastewaters.	Rare	High	Moderate	Moderate	Food processing industry	Reduced organic loads	None known
Purification of wastewater from the sugar industry	Purification of organic wastewater with activated sludge in one or more aeration stages.	Rare	High	Low	High	Sugar industry	Reduced organic loads	None known
LEMNA wastewater treatment system	Wastewater treatment using duckweed.	Moderate	Low	Low	Moderate	Rural areas	Cost effective	Low level of treatment
Land treatment of wastewater using poplar trees	Controlled application of wastewater to the land surface.	Rare	Moderate	Low	High	Rural areas	Economic value added	Low level of control Large land area requirement
Hydrobotanical treatment	Treatment of wastewater using natural processes.	Rare	Moderate	Low	High	Widespread	Flexibility of construction	None known
EGALAIR wastewater treatment	Biological sewage treatment plant based on total oxidation.	Moderate	Low	Low	Moderate	Areas with warm climates	Cost effective	Large land area requirement
Bio-clear wastewater treatment system	Wastewater treatment using one or two stage biological treatment.	Rare	Low	Low	Moderate	Rural areas	Cost effective	Low level of control
Bio-system 2000 radical treatment method	Wastewater treatment using microorganisms to produce fertilizers.	Rare	Low	Low	High	Widespread	Low energy consumption	Proprietary process
Packaged wastewater treatment plants	Compact wastewater treatment units for use in small settlements.	Rare	Moderate	Moderate	High	Small towns and villages	Small land area requirement	Sensitive to cold weather
Mechanical separation and dewatering of waste	Screening, pressing, and clarifying treatment.	Rare	Moderate	Low	High	Widespread	High degree of reliability	Highly sophisticated technology
Oxidation and stabilization ponds	Anaerobic, aerobic, facultative, and aerated ponding to treat sewage.	Moderate	Low	Low	High	Rural and suburban areas	Economic Ease of use	Large land area requirement
Reuse of cooling water for fish farming	Reuse of heat-polluted cooling water for fish farming.	Rare	Moderate	Moderate	High	Power generation industry	Reduces thermal pollution	Large land area required
Reuse of wastewater from an edible snail processing factory for irrigation of a snail growing farm	Mechanical and chemical pretreatment sewage for reuse.	Rare	Low	Low	Moderate	Food processing industry	Economic	None known
Oxidation ditch	System for the treatment of domestic wastewater for small communities.	Moderate	Low	Moderate	Moderate	Suburban areas	Ease of use Simplicity	High energy requirement
Irrigation of agricultural lands with liquid manure	Liquid manure is diluted with surface water and used for irrigation.	Moderate	Moderate	Moderate	High	Rural areas Agricultural industry	Economic	Over-fertilization
Agricultural stabilization ponds	Anaerobic, aerobic, facultative, and aerated ponds used to treat raw sewage.	Moderate	Low	Low	High	Rural areas Agricultural industry	Economic	Large land area requirement
Freshwater augmentation
Beaver reintroduction	Beaver-ponds and vertical wells enhance groundwater recharge.	Rare	Low	Low	Very high	Rural areas with suitable beaver habitat	Ecosystem restoration Fur production	Low level of control Damage to riparian forests Flooding
Collection and reuse of stormwater	Reuse of stormwater for street cleaning, cooling, watering, etc.	Rare	Moderate	Low	High	Urban areas	Economic	Poor water quality prior to use
Efficient water use in small hydropower plants	Scheduling for more efficient use of water resources.	Rare	Low	Moderate	Very high	Hydropower generating industry	Increased profit	None known
Collection of rainfall and snowmelt water - STERA	Collection of snowmelt and rainwater in the barrels.	Extensive	Very low	Very low	Low	Rural and suburban areas	Economic	Poor water quality
Reuse of clear mine water	Reuses freshwater from mines.	Rare	Low	Low	High	Mining industry	Increased profit	Variable volumes available
Mine water reuse as drinking water source	Reuses freshwater from mines.	Rare	Low	Low	High	Mining industry	Increased profit	Variable volumes available
Ponding	Regulation of natural water circulation using artificial catchments.	Extensive	Low	Low	High	Rural and suburban areas	Simplicity	None known
Rainwater ponding	Rainwater harvesting using small dug ponds.	Extensive	Low	Low	Low	Rural and suburban areas	Improves microclimate	None known
Fire-protection reservoirs	Rainwater harvesting using fire protection reservoirs.	Moderate	Low	Low	Low	Rural and wooded areas	Water for fire protection	None known
Upgrading quality of natural water
Desalination of mine water	Desalination of water from mines with highly saline wastes.	Rare	High	High	High	Mining industry	Reduced salt loads	10-year payback period
Remediation of polluted sites	Treatment of contaminated groundwater	Rare	High	High	High	Polluted sites	Environmental restoration	None known
Lake rehabilitation	In-lake treatment to control eutrophication.	Rare	High	Moderate	Moderate	Polluted lakes	Aesthetic Environmental restoration	None known
Biofiltration	Use of common mollusc species for wastewater treatment.	Rare	Low	Very low	Moderate	Polluted lakes	Environmental Economic	Waste utilization

5. Organization of the Source Book

This Source Book is presented in three parts. Part A provides an overview of the technologies included in the Source Book and a guide to the use of the book. Part B sets forth a series of technology profiles which briefly describe each of the technologies used to maximize water use efficiency and augment existing water supplies in Eastern and Central European countries, in a consistent and comparable manner. Part C presents selected case studies which highlight the use of specific, innovative technologies described in Part B.

In Part B, each technology profile presents the following information:

· Technical Description, providing a brief description of the technology as applied in the region;

· Extent of Use, indicating the extent to which the technology is applied in the region;

· Operation and Maintenance, describing the operation and maintenance of the technology;

· Level of Involvement, indicating the level of involvement of government, community organizations, private sector organizations, and households needed to implement and maintain the technology;

· Costs, providing information on capital and operating and maintenance costs;

· Effectiveness of the Technology, describing the ability of the technology to accomplish the objectives of application for which it is designed;

· Suitability, describing the geographic and/or hydrological areas where the technology is most applicable;

· Advantages, presenting the political and technical advantages of the technology;

· Disadvantages, presenting the political and technical disadvantages of the technology;

· Cultural Acceptability, describing any socio-cultural inhibitions or barriers to the use of the technology within the region;

· Further Development of the Technology, indicating any additional development needed for apply this technology more widely or in other areas of freshwater management; and,

· Information Sources, providing additional references to the published literature and/or the names and contact details of water resources professionals within the region having experience with, or knowledge of, the technology that might be useful to the reader in determining the suitability of the technology for a similar application.

The technology profiles are presented as follows: freshwater augmentation technologies, water quality improvement technologies, wastewater treatment technologies and reuse, and water conservation technologies.

1.1 Drip-irrigation system

Technical Description

Drip irrigation systems allow the more efficient use of water in agriculture. Water in the system is distributed directly to each cultivated plant and dosed in a controlled manner by drippers. The main components of such a system include the sprinkler lateral and its parts; the dripper lines; a pressure compensator; pressure and water quantity metering instruments; water treatment facilities and fertilizer injectors; and, automation systems, if used. The most refined technologies have an integrated multi-system controller, including computerized micro-climate weather monitoring sensors, humidity and temperature sensors, and computerized control of rates of irrigation and fertilization. This technology provides precision irrigation monitoring, accurate irrigation direct to the point of greatest water need, and controlled fertilization.

Extent of Use

Irrigation is very important in providing water for agriculture in Hungary, Bulgaria, and Romania. As a consequence of the unusually long drought in the region, which lasted from the early eighties until 1993, countries such as have developed and implemented increasing numbers of drip irrigation systems as an economical, water saving and effective method of irrigation. For example, in Hungary, the extent of drought prompted the development and implementation of a "drought index", the PAI, which is calculated in terms of relative temperature and precipitation, and which reflects the monthly change in the water demands of crops (and, indirectly, the position of the groundwater tables). In 1993, the national average value of PAI drought index was 9 C/100 mm, indicative of heavy drought conditions. The drought affected 78 000 km², or 84% of the total area of the country. Of this area, 8 274 ha were considered to be technically equipped for the application of supplemental water through irrigation, but only 4 847 ha were actively irrigated. Given these circumstances, there was a great need to find the most effective method for application of irrigation waters, and, as a result, more and more of these drip irrigation systems were developed and put into practice in Hungary during the 1990s.

Operation and Maintenance

Depending on the size of the irrigation scheme and complexity of the system design, the principle operating requirements include standard control, repair, and adjustment procedures. System design parameters should be planned on the basis of climatic data, physiographical relief, hydrological data, soil conditions, type of cultivation, crop water demand, and irrigation times. Such data will allow the system to be adequately sized for the particular application.

Level of Involvement

Drip irrigation systems are implemented at the household and agro-company levels.

Costs

No cost data were available. However, because these systems generally use readily available PVC and polyethylene piping systems, they are generally cost competitive with traditional spray irrigation systems based on steel or aluminium piping. Notwithstanding, there is a moderate to high capital cost associated with the application of this technology.

Effectiveness of the Technology

This technology is highly water-efficient, resulting in fewer transmission losses than traditional irrigation techniques.

Suitability

The drip irrigation method is suitable for cultivation of edible (grapes, fruits, and vegetables) and ornamental (nursery stock) plants with high commercial value. This system may be used not only to increase soil moisture but to apply fertilizers and micronutrients as well.

Advantages

This technology improves the growth rates of high value crops by delivering moisture directly to their root zones. This saves water because only the important part of the plants are irrigated. Weed growth is reduced since only the plant is irrigated, and working between the plants is easier because of the dry soil. This technology can be used in hilly terrain, and is not labour-intensive as it can be automated. The technology can be adapted to use energy-saving components.

Disadvantages

The technology is not well suited to machine-based cultivation, as the machinery may damage the pipelines. If not properly applied or monitored, these systems can increase the salt concentration of certain soils and result in over-irrigation. The capital costs of the equipment needed to employ this technology may be higher than those for surface or sprinkler irrigation systems. Drip irrigation also suffers from the tendency for the drippers to become stopped up easily.

Cultural Acceptability

The method is fully compatible with traditional methods of irrigation used in southern parts of Europe.

Further Development of the Technology

The technology is one of the simplest irrigation methods and fully developed.

The NETAFIM® Drip Irrigation System The NETAFIM drip irrigation system is an example of one type of irrigation technology, developed in Israel and being used in Hungary, which employs pressure-compensated dripperlines equipped with a proprietary pressure differential mechanism. The dripper maintains a constant discharge rate over head pressures ranging from 5 to 40 m, and lateral distances of up to 800 m. The system can accommodate a range of dripper spacings and discharge rates, and uses various wall thicknesses in the transmission lines to compensate for the wide range of operating pressures. The system can also be used with wastewater sources and has a high resistance to mechanical damage. Unit costs of using this technology depend on the size of the irrigated area and type of equipment necessary. A 20 ha area using 32 640 m³/yr of water demand (= and application rate of 163 mm/yr), with filtering system, fertilizer injector, electric pump, pipeline system, dripper lines, buffer pond, and water supply well would incur a capital cost; of about $48 000. The cost of operation and maintenance is also dependent on design factors. A 3 ha area for growing cucumbers, using water supplied from a well equipped with electric pumps, would incur costs of about $850/ha, although experience indicates that the unit operation and maintenance costs decrease as the irrigated areas increases. On a bigger irrigated farm the unit costs would be cheaper.

Information Sources

PetKovac, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

Dr Korna N. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

1.2 Non-invasive renewal (enlarging) of pipes

Technical Description

This technology, also known as one form of trenchless technology, allows the for non-invasive replacement of an existing pipeline. Replacement is accomplished by inserting an hydraulic tool into an existing pipeline. As the hydraulic tool is moved along the pipeline, the application of hydraulic pressure causes the head of the tool to expand, destroying of the old pipe. As a consequence, a new pipe of the same or larger diameter may be hydraulically inserted into the space in which the old pipe was located. The technique is considered non-invasive as there is little disruption of the land surface, with all hydraulic operations being undertaken through relatively small excavations at intervals along the pipeline route. This is in contrast to the more common surface excavation methods.

Extent of Use

This is innovative method gradually coming into use in Poland and Latvia.

Level of Involvement

This technology is generally implemented construction firms, service or utility agencies, and local governmental administrations.

Operation and Maintenance

This technique is used in the non-invasive breaking of cast-iron, stoneware, concrete, and asbestos pipes, and is best operated by specialist contractors. The technique employs specialised equipment. Because this technology is often used in conjunction with a pipeline renewal project, it would be important to ensure that complementary hydraulic methods of inserting new piping be available.

Costs

Relatively to diameter of pipe and nature of the ground in which the original pipeline was laid, costs of using this technique range between $160 and $320/m of pipe. This cost is still not competitive relative to traditional, surface excavation methods for general use.

Effectiveness of the Technology

This is a very effective method of renovating pipeline system, and is especially useful in confined urban areas where surface excavation may not be possible or desirable.

Suitability

This method can be used in all countries of the region.

Advantages

This technique has few environmental consequences and is much less disruptive to business and industry than comparable surface excavation techniques. Pipe networks that have become corroded can be renewed in place, while pipe networks that are undersized for current demands can be replaced without removing the old pipeline, which could reduce the amount of time customers are without service. Because most of the renewal in carried out underground, the pipeline project can be completed with minimal disruption of business operations.

Disadvantages

No disadvantages have been identified, although the technique currently is more expensive for general application than surface excavation.

Cultural Acceptability

This innovative method is being increasingly accepted by civil engineering societies. The limited surface excavation also typically means that this technology is well accepted by the general public, who are less inconvenienced by this technique.

Further Development of the Technology

There is a need for the benefits of using this technology to be made more visible to contractors and consumers.

Information Sources

Reno Rur Centrum Sp. z o.o., Kielce, ul. Warszawska 34, skr. poczt. nr 624 Poland, Tel. (048-41) 411-41 w. 286, Tel./fax: (0-48-41) 44-330.

1.3 Non-invasive renovation of pipes

Technical Description

This technology, a companion technique to the trenchless technology described above, is also known as lining. Short segments of piping are inserted into an existing pipeline and moved along in the direction of flow using hydraulic or mechanical means. The mechanical variation uses chains to move the liner along inside the old pipe, while the hydraulic option uses hydraulic rams to push the liner into place. If there is sufficient space between the liner and host pipe, the space may be filled with aggregate.

Extent of Use

This technology is being used in Poland by private contracting firms.

Level of Involvement

This technology may be implemented by private companies, service or utility firms, and local governmental administrations.

Operation and Maintenance

This is a non-invasive method and requires no excavation prior to the placement of pipe. Liners may be inserted into existing pipelines through manholes or other surface entry points. The technology requires specialist operation and specialised equipment.

Costs

Relatively to the diameter of pipe being repaired, costs range from $100 to $200/m, which is competitive with excavation work.

Effectiveness of the Technology

High effectiveness in the case of corroded and leaky pipes.

Suitability

The technology is suitable for use in all countries within the region.

Advantages

Lining provides greater integrity within the pipe network and may increase the durability and resistance of the pipeline against corrosion. This technology takes advantage of existing pipelines and does not result in disruption of roadways or land surface activities.

Disadvantages

This technology has no identified disadvantages, although lining may reduce the capacity of the lined pipe by the thickness of the liner. Hence, lining may not be suitable for use in pipe networks operating at or near capacity.

Cultural Acceptability

This method is accepted by civil engineering societies. The limited surface excavation also typically means that this technology is well accepted by the general public, who are less inconvenienced by this technique.

Further Development of the Technology

There is a need for the benefits of using this technology to be made more visible to contractors and consumers.

Information Sources

Reno Rur Centrum Sp. z o.o., Kielce, ul. Warszawska 34, skr. poczt. nr 624 Poland, Tel. (048-41) 411-41 w. 286, Tel./fax: (0-48-41) 44-330.

1.4 Collection and reuse of stormwater

Technical Description

In developing urban areas, stormwater can be gathered in separate stormwater sewers and reused after simple treatment for washing streets, cooling, watering of gardens, and other purposes requiring nonpotable water. In addition to providing this reuse potential, this technology makes possible the treatment of urban runoff before it enters waterbodies. The simplest form of stormwater treatment consists of open or closed sedimentation basins, retention ponds, or storm sewer, in-line separation chambers for capturing oil products. Stormwater management technologies include provision of grit chambers and swirl separators within sewer mains, and skimmers which capture floatable solids and oil products from the water surface of basins. Infiltration ditches also can be used for filtration of oil products.

Extent of Use

As a rule, in the central and oldest parts of Central European cities, stormwater is conveyed in combined sewer systems to municipal treatment plants, and discharged, following treatment, to receiving waterbodies. In a few newer urban districts, separated sewer systems have been constructed which allow for stormwater reuse. However, this technology is not very popular and not widely used.

Operation and Maintenance

Regular inspections during rainy weather should be conducted to minimise the occurrence of blockages within the collection system. If basins are used, mowing of the grass within the basins, periodic removal of sediments, and cleaning of the outlet pipe are also required. Litter, soil, and leaf removal is required from in-line separators.

Level of Involvement

This technology is best implemented at the municipal government level.

Costs

Costs are different according to local conditions, possibilities for stormwater usage, and existing infrastructure. Because dual collection systems are required for stormwater and wastewater conveyance, the costs may be higher than for combined systems (which may require larger diameter pipe networks to convey the higher volumes of wet weather flows).

Effectiveness of the Technology

The efficiency of this technology when combined with simple pond-based treatment facilities is high, with approximately 80% of oil products and suspended solids being removed from the stormwater. Depending on the area drained by the system, a large volume of water can be saved if stormwater is reused for purposes requiring low quality source waters.

Suitability

Reuse of stormwater can be a favourable option for municipalities with scarce water resources and an high demand for low quality, nonpotable water. The desirability of stormwater reuse is strongly dependent on general environmental quality and pollution within the rainwater catchment area, and may vary depending on the intensity and duration of storms and the length of the period between storms. Stormwater quality also varies within individual storms, with water quality at the beginning of a storm pollution being poor (known as the "first flush" effect). Also, the quantity of stormwater is variable, with periodic high flows during storms and low or no flows between storms. Hence, detention ponds, using biological treatment, are often used as such ponds are most flexible with regard to volume. Nevertheless, it is important that such ponds are of adequate volume to detain between a 2 and 100 year recurrence interval design storm, so that the runoff is not discharged into waterbodies without sufficient treatment. Because water quality of the runoff generally improves during the course of a storm, the degree of impairment at the end of the storm is rather low and this water can be reused after simple treatment or discharged into waterbodies without a significant pollution risk. Investigations of the stormwater flows show that long rains of low intensity create greatest pollution loads to surface waters. Table 2 presents a summary of the principle chemical characteristic of stormwater based on pollutant concentrations reported in the literature. The Table clearly shows that pollutant concentrations are such that treatment should be provided prior to discharging the runoff to natural water courses.

TABLE 2. Typical Pollutant Concentrations in Stormwater in Eastern Europe.

Pollutant concentration (mg/l)	Rainwater	Snowmelt	Street wash water
Suspended solids	50-16 000	570-6 580	30-8 300
COD	24-260	33-250	35-280
BOD5	10-285	5-270	6-225
Chlorides	10-35	35-1 600	11-37
Oil products	2-24	35-72	2-72

Advantages

Using low quality water for nonpotable needs, instead of potable freshwater resources, augments the available supplies of the latter. Providing treatment of stormwater runoff from urban areas also provides an opportunity to upgrade degraded natural waters that have previously received untreated stormwater discharges.

Disadvantages

Because limited treatment methods of purifying stormwater are used, effluents may remain contaminated with persistent pollutants like heavy metals, and, in consequence, should not be used for gardening purposes if the produce is intended for human consumption. Use of contaminated stormwater may lead to contaminant accumulation in the soil.

Cultural Acceptability

This technology is culturally acceptable. Its use is largely outside of the public eye, and, hence, is mainly of concern to administration staff and workers.

Further Development of the Technology

Better schemes of the assessment of environmental impacts connected with stormwater use for various purposes need to be developed. Given that treatment is often needed, improved methods of purifying stormwater, that are inexpensive and simple to install and operate, should be developed.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Street, 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

1.5 Rainwater and snowmelt collection

Technical Description

Rainwater or melted snow water is gathered from rooftops in the barrels or other containers. Alternatively, another traditional method of harvesting rainwater involves the use of small dug ponds to harvest rainwater in rural areas. Water from the pond can be later used for watering vegetable gardens. In Albania, rainwater, gathered from the roof, is conveyed through a gutter or water spout to a Stera, or storage tank within the house, from which it is used. The water is obtained from the well of the Stera by means of a handpump or hand winch.

Figure 1. Rainwater harvesting technology used in Albania.

Extent of Use

This technology is used, in many variants, in rural areas throughout the region. The Stera is used in Albania in areas that lack natural, groundwater springs; for example, in the City of Gjirokastra and its surrounding villages. Collection of rainwater in surface ponds is a traditional method of rainwater harvesting in Latvia and other Baltic States. Almost every farm has a small pond for watering vegetable gardens. However, in Latvia, water harvested by this means produces less than 50% of the total quantity of water consumed for household-level irrigation.

Operation and Maintenance

The operation and maintenance of this technology is simple, requiring only good housekeeping to ensure flowing gutters and drain spouts. Occasional repairs to rooftops and other structures may be required.

Level of Involvement

This technology is implemented at the household level.

Costs

Costs of Using this technology are negligible, as clean, old barrels and similar containers can be utilized for the purpose of catching and storing rainwater from rooftops. However, some cost may be incurred by householders should they wish to use ferrocement storage tanks or other constructed tank system. Other costs are labour costs associated with the construction of the harvesting system.

Effectiveness of the Technology

There are no statistics on rainfall and snowmelt water consumption, but it is estimated that about 5 million households in Ukraine collect water in this manner. Each household is estimated to collect from 20 000 to 30 000 l/year of rainwater, which corresponds to between 5 000 and 7 500 l/capita/year, or 14 to 20 l/capita/day. The typical Stera has a volume of 30 to 40 m³. Water from the Stera is used primarily during the warm and dry to wash or to water gardens around the house.

Suitability

This method is traditional in individual houses in the villages and some larger cities in Ukraine, and is a popular technique for supplementing freshwater availability. Also, the Stera is used in some rural areas in Albania. This technology is most suitable for use in all parts of Europe with good quality rainwater, appropriate surface structures, and adequate hydrological conditions. In Latvia, the dug ponds are situated in the places where the groundwater table is low and replenishment with surface flow and groundwater is sufficient to maintain the pond volume year round.

Advantages

Historically, the main reason for rainwater harvesting was the fact that rainwater is softer than the hard, cool groundwater available from wells. The technique continues to be popular as a means of supplementing available water for gardening and bathing. In the eastern part of Latvia, where the traditional product is flax, rainwater ponds have been used to store water for use in resting linen for centuries, although in recent years production of linen has decreased considerably.

Disadvantages

This method has limited utility due poor rainwater quality in many parts of the region. Rainwater is also susceptible to contamination due to litter and animal droppings deposited on rooftops or into storage tanks.

Cultural Acceptability

Due to environmental pollution in many parts of the region, the use of rainwater is limited and unattractive as a result of acid rain and contamination following the Chernobyl nuclear accident. Following the Chernobyl incident, the use of rainwater for washing has diminished.

Further Development of the Technology

The usefulness of rainwater harvesting in Central and Eastern Europe as a freshwater resource depends on measures taken to preserve its quality. Greater use of rainwater in the future will be related to progress in air pollution control.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Street, 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Mirela Cekani, Department Microbic Research Institute of Hygiene and Epidemiology, Rruga P.N. Luarasi, Pall 14/5, sh 2, ap. 13, Tirana, Albania, Tel. (355-42) 34142.

Dr Vladimir Demkin, Ministry for Environmental Protection and Nuclear Safety of Ukraine, 5 Khreschatyk St., Kyiv-1, Ukraine, Tel./fax: (380-44) 228 0786, fax: (380-44) 229 8050, e-mail: demkin@mep.freenet.kiev.ua.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

1.6 Runoff collection using surface structures

Technical Description

Water storage is an important method for artificially regulating natural water circulation to harmonize society's demands for water with the availability of surface water resources which change in time and space due to climate and topography. This storage is often accomplished through the construction of dams to create reservoirs of surface water along a naturally-occurring water course. Reservoirs may be divided into different types on the basis of site (highland and lowland reservoirs), size (small, medium, and large reservoirs), intended purpose (irrigation, water supply, fish production, hydropower generation), and technical design (river dam reservoirs and retention/detention water storage ponds). One example of a lowland reservoir is the RReservoir which was built in the late 1980s with a working water level storage water capacity of about 9.07 million m³ and a surface area of 3.89 km². The average depth is 2.35 m. The maximum water storage capacity is 13 million m³, at a surface area of 4.27 km². This reservoir services a drainage network downstream of the reservoir that includes a carrier canal, pumping stations, and a number of sluices. In addition, a volume equivalent to the full volume of the reservoir can be discharged into the Tisza River or into the Belfainage system through a series of small water flows. A further example is the use of surface storages to regulate water resources to conserve water in water poor areas and for soil conservation.

In addition, dams have been used in Latvia for this purpose for centuries with good result. There are more than 1 000 large reservoirs and many thousand smaller reservoirs and ponds in Latvia with a total surface area of 424 km² and a total volume of 2.07 km³, providing a useful volume or yield of freshwater of 0.33 km³. The primary use of the small reservoirs is for fire-protection in rural areas and forests. These reservoirs typically have a volume of between 10 m³ and 100 m³. The least complex reservoirs are clay lined, although the larger reservoirs have concrete or plastic basins covered with between 0.2 m and 0.5 m of soil.

Reservoirs serve not only as water storage facilities, but also work as biological wastewater treatment systems, places for recreation, and aesthetic landscape elements.

Extent of Use

In Hungary, reservoirs provide an important element of the freshwater supply. Because 95% of the water consumed within Hungary originates outside of the national borders, provision of surface storage by means of reservoirs provides a degree of water security for the country. There are 600 reservoirs that have individual storage capacities larger than 50 000 m³. The largest is the Tisza Reservoir, which has a usable volume of 300 million m³.

Operation and Maintenance

The major element in the operation of surface water storage ponds in the construction and maintenance of the hydrological structures, including the barrier wall, water control gates, and associated canals and outlet pipes. In multi-purpose reservoirs, maintenance may also include the upkeep of turbines or other equipment.

Level of Involvement

Implementation of this technology is usually carried out by regional administrations with, in some cases, government oversight, administrative decision-making, and scientific and technical research and expertise. Where reservoirs are constructed for specific purposes, such as the fire prevention, or are constructed in response to specific legal requirements, implementation of the technology should include governmental and administrative unit involvement to ensure that design specifications are uniform and that the systems are maintained. After the big forest fires in Poland in 1993, it turned out that, in many wooded areas, the volume of available water was drastically insufficient as a result of lack of such oversight.

Costs

Costs depend upon scale of a given project. Construction costs range from $0.16/m³ to $0.60/m³ for large dams, and from $1/m³ to $5/m³ for smaller sized structures. If large dams are built in an environmentally sound manner, and have no significant hydraulic problems, maintenance costs are low and the structures can be operated without specialized staff. Small dams have few costs, although they must be inspected periodically to ensure that they are not subject to siltation or misuse.

Effectiveness of the Technology

Effectiveness is determined by the hydrological regime, scale, and design of the project. Generally, well-designed and sited reservoirs are very effective means of storing freshwater. In Latvia, as a result of afforestation projects that are reclaiming formerly agricultural lands, the importance of smaller reservoirs for forest fire protection will increase, and it is anticipated that large numbers of additional ponds will be built.

Suitability

Technology suitable for most of geographic and hydrological areas excluding sites with unfavourable geology; i.e., those areas with fractured or porous bedrock that cannot be sealed to retain surface water or support a structure.

Advantages

The main goals of reservoirs are storage of excess surface water and flood control by attenuating the downstream effects of the flood peak. In turn, the reservoir provides water suitable for irrigation use and support of fish stocks. Recreational activity is also possible on and around reservoirs. Because of the head differential between the water surface and the river bed, most reservoirs also have the capacity for power generation, a capacity enhanced by the development of low-head turbines in recent years (see below). Construction of smaller reservoirs for fire protection not only provided increased resistance for forest fires due to their microclimatic effects, but also make available additional water for use during extreme droughts.

Disadvantages

Reservoirs create extensive land-use changes, wherein agricultural bottom lands are inundated and habitat is disturbed. Such disturbances lead to potentially severe environmental impacts depending on the size of the impoundment, including changes in the microclimate in the vicinity of large impoundments and both terrestrial and aquatic ecological disturbances. Because they are artificial structures, reservoirs can both add and detract from the aesthetic value of landscapes, depending on their design and construction.

Cultural Acceptability

Generally, impoundments are an acceptable technology. However, because of the land-use changes inherent in dam-building technology, cultural and social problems occur within the communities directly impacted by the construction process. Fire prevention reservoirs are well-accepted in forested region of Europe.

Further Development of the Technology

Future dam construction will be subject to intense environmental scrutiny, focussing not only on direct, in-basin impacts but also hydrological optimalization, including in stream flow regulation. In Poland, where there are a few large dams, some lack adequate land use control measures within their catchments for the protection of water quality, which has resulted in rapid water quality deterioration due to accelerated eutrophication. Notwithstanding, the dam construction technology is a well-established technology.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Street, 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

1.7 Rational dosing of washing powder

Technical Description

Every year the typical Pole consumes over 7 kg of washing powder. For a typical family of four persons, this amounts to 28 kg of washing powder discharged each year to natural water courses in domestic wastewater with potentially adverse environmental consequences. Due to the dynamic development of the household chemical industry, consumers have a wide choice in washing agents, which vary both in terms of their efficiency and potential harm to the environment. One means of managing their environmental impact is to improve the efficiency of the washing agents, or by providing the same or improved quality of washing at a lower dose of washing agent (see Case Study in Part C, Chapter 5). In order determine the rational dosage of washing agent to use for any given application, it is necessary to know the hardness of the water as hard water requires an higher dosage of washing powder than soft water. Information on the hardness of the water can be obtained from the water supply utility, while information on the proper dosage of washing powder should be included in the instructions for use which are provided with the packaging. It is important to provide a convenient means to measure the amount of washing powder with the product to avoid excessive use. It is also important that the consumer be made aware that excessive use of washing powder does not ensure a better washing result.

Extent of Use

This technology represents a simple, consumer-information campaign that can be used in each country within the region. Provision of information through advertising, by soap manufacturers and by washing machine makers, can alert people to the environmental damage caused by washing agents discharged to the environment, and to basics of effective washing.

Operation and Maintenance

Operations and maintenance is simple: appropriate dosing of washing agents can be carried out at the household level as part of the daily housework done by most people, or at the commercial level by laundries, etc. This technology is clearly connected to consumer habits.

Level of Involvement

This technology may be implemented at the household level, and at the industry level by the producers of washing powders and commercial users of washing agents. The implementation of this technology can be facilitated by national and international organizations seeking to achieve standardization and provide monitoring of information delivered to consumers with commercial products.

Costs

This method may benefit the consumer in lower washing costs. While some changes in production processes may be required by soap manufacturers, most laundry equipment in current use will not require any modification. Hence, this technology is a low cost/no cost technology.

Effectiveness of the Technology

This technology is effective in reducing the total amount of substances harmful to the environment, including phosphorus. According to Polish data, a 10% to 30% overall reduction in phosphorus discharged to environment is possible.

Suitability

This method is suitable for use throughout the region.

Advantages

The simplicity of the technique and measurable savings for the consumer make this an attractive technology which provides significant environmental benefit.

Disadvantages

Aside from some higher production costs incurred if low phosphate detergents are manufactured, there are no known disadvantages inherent in this technology.

Cultural Acceptability

This technology is in general culturally acceptable, although a concerted consumer education campaign is usually necessary to overcome the traditional washing habits which people learn from their parents.

Further Development of the Technology

The development of this technology requires social education, advertising company promotion, and, perhaps, changes in manufacturing processes, all of which may be considered well-developed.

Information Sources

Ryszard Janikowski, Institute for Ecology of Industrial Areas, ul. Kossutha 6, Katowice, Poland, Tel. (48-32) 1546031, fax: (48-32) 1541717, E-mail: jan@amnesia.ietu.us.edu.pl.

Associations of Producers for Cosmetics and Household Chemicals, ul. Marszalkowska 84/22, 00-514 Warszawa, Poland, Tel. (48-32) 295976, fax: (48-32) 6218466.

1.8 Lining of solid waste disposal sites

Technical Description

As the standard of living increases, the quantity of resulting waste increases as well. In Hungary, it is estimated that 20 million m³ of solid waste is produced annually. However, only 14 million m³ is collected for disposal at identified disposal sites. The fate of the remainder is unknown, but may be assumed to be informally disposed of outside of the identified disposal sites. This informal disposal continues for various reasons, including distance from formal collection and disposal systems, cost of disposal, nature of the materials being disposed of, and tradition. Hence, domestic waste disposal is not a simple issue, even though it is ubiquitous in nature. Serious problems in waste management exist throughout the region.

The usual waste disposal site is a simple pit or natural depression in the land surface into which refuse is dumped without any engineering or pollution prevention measures being considered. Such dumps can contain everything from harmless substances (such as food waste) and reusable materials (such as paper and plastics) to extremely hazardous chemical wastes (such as printers waste, machine shop chemicals, and spent solvents and cleansers). There have been several attempts to organise selective collection of wastes within the region, but most have had little success to date.

Establishment of an engineered landfills is also a common method of waste disposal, designed to control the emissions of, particularly, hazardous substance to the environment. The overall design of secure waste disposal facilities should include control of the top of the waste pile to minimize atmospheric emissions and infiltration of precipitation (i.e., capping), and control of the bottom of the waste pile to maximize the collection of lecheate and minimize contaminant transport through the bottom (i.e., sealing). The facilities typically are designed, and sites selected, in response to individual soil characteristics on the sites, and the more modern facilities are isolated from the underlying groundwater by various lining materials. Similarly, waste piles are also isolated from surface infiltration by the placing of an impervious cap at the top of the pile. Guidelines for the selection of lining and capping materials for specific sites have been published in the relevant technical literature; however, lining and capping options include mineral sealing layers (clay linings and caps) and multiple layer seals (clay linings and caps combined with high density polyethylene geomembranes). Such linings act to minimize releases of contaminants into the environment, and to control seepage from the landfills so that contaminants leaching from the landfills are treated and enter the environment at an acceptable or non-detectable rate.

Within the region, communities are moving from the use of traditional dumps to secure landfill technologies. For example, the City of Nygyh, Hungary, when faced with a serious waste disposal problem caused by the old, unprotected dump site being filled to capacity, decided to create an environmentally-safe landfill for the disposal of non-recyclable solid wastes. This facility was constructed adjacent to an existing landfill near Nygyh-Oros, and the first, 245 000 m³ capacity phase of the project opened during 1984-85. The second phase of the project is intended to increase the capacity of the site constructed under phase one, providing for up to 12 years of waste disposal capacity. A key feature of the new waste disposal system is the elimination of the reusable and recyclable wastes from the waste stream. Such elimination will help to prevent the transformation of wastes into polluting materials which could potentially pose an environmental threat to the inhabitants. A further feature of the new waste disposal system is the use of a lining and drainage system to protect the Pleistocene aquifiers found in the area.

The landfill was constructed with a four-layer, composite lining with a drainage system for the collection of lecheate, a monitoring system with sensors and monitoring wells, lighting, and protective landscaping. The lining system was constructed with the following layers: a soil layer to protect against mechanical damages, a leachate collection zone, a primary barrier layer of 2 mm PHDE (High Density Polyethelene) GUNDLE® geomembrane made with double seam welding and control channels including an electrode-based damage detection system, and a CONSOLID® clay mineral sealing layer with an infiltration coefficient, K, of between 1 and 5 x 10^-9 m/s. This lining system was installed over a graded subsoil base.

The original clay mineral seal was a 25 cm thick layer of clay placed under the primary sealing layer. Due to technological developments adopted by the contractor, CONSOLID Ltd., the thickness of this clay seal has been reduced to 12 cm by using a clay mixture consisting of clay and the additives C 444® (1%), Solidry® (4 kg/m²), and sand. These additives provide additional control of contaminants that may pass through the primary sealing layer.

Leachate is collected by a drainage system placed beneath the waste pile, and is re-used to irrigated to the top of landfill, from which it evaporates, to control dust formation.

The monitoring system provides continuous assurance of the integrity of the primary seal. In the event that this integrity is compromised, the sensor network can help to identify the exact location of the damage with an accuracy of about 150 mm.

Figure 2. Cross-section of a composite liner system.

Extent of Use

This technology has been used at newly-constructed waste disposal sites in Hungary, Poland, and Latvia.

Operation and Maintenance

The technology does not require specialized operation and maintenance provided that the landfill has been proper planned and constructed, with adequate pollution control measures provided. Depending on the materials disposed of in the landfill, however, it might be necessary to undertake limited repairs in the event of the liner being punctured. Generally, the cost of the maintenance is met by local government from fees collected for the waste collection and disposal.

Level of Involvement

This technology is typically implemented at the municipal level, but may be implemented by industries generating large volumes of solid wastes.

Costs

In the Hungarian example, the construction cost of the landfill was $608 000. The sensor system, provided in addition to the site construction, cost an additional $32 000 or 1$/m².

Effectiveness of the Technology

This technology is effective in protecting groundwater and surface water resources from pollution.

Suitability

This technology is suitable for use at most municipal and industrial waste disposal sites.

Advantages

This technology provides for the protection of water resources. If combined with a leachate collection and pumping system, this technology can also minimize dust formation from solid waste disposal sites.

Disadvantages

There are no known disadvantages to this technology if it is properly sited and installed.

Cultural Acceptability

This technology is culturally acceptable.

Further Development of the Technology

Identification of less costly sealing materials could accelerate the use of this technology. Promulgation of appropriate solid waste disposal regulations and standarization of siting and design criteria would be very important complementary actions supporting the use of this technology.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

1.9 Use of clear minewater

Technical Description

The process of dewatering is an important element of mine safety in order to reduce the possibility of inundating mining operations. In Latvia, this process has been linked to the provision of freshwater, after appropriate treatment, for various purposes including irrigation of agricultural lands, creation of recreational lands, manufacture of building materials, and aquaculture. Beginning in 1980, projects to reuse minewater, to treat minewater prior to its discharge to surface waters, and to reclaim inactive mine sites have been implemented by the state corporation, Meliorprojekts. There are over 100 disused quarries in Latvia, or which only small number have been reclaimed and recultivated for use as water reservoirs for regional (landschaft) development, recreation, fishing, and irrigation. In Hungary, the Danube River Regional Water Works Company supplies drinking water to the medium sized Town of Szekesfehervar and its surrounding villages and three large industrial consumers from bauxite mine. To support development of the mine, an high capacity production well was built to de-water a 1 km long gallery constructed at a depth of between 280 m and 300 m below the land surface. The karstic water abstracted by this system is of high quality and satisfies Hungarian standards, after chlorination, for drinking water supply.

Extent of Use

In Latvia, minewater comes from open clay, sand and gravel pits, and from dolomite, sandstone, and other building material quarries. The volume of minewater abstracted from these mines has reportedly diminished from 21 million m³/year in 1990 to 12 million m³/year in 1994, although this diminution can be interpreted as reflecting not only lower rates of production in older mines but also lack of reporting by small and private mines. Further, water abstracted from peateries is not designated as minewater and not accounted for in the above volume. A majority of this water is discharged to natural waterbodies without reuse or treatment. Notwithstanding, this water does contribute to the replenishment of natural discharges in rivers and attenuation of their discharge curves. However, this water also contributes to the thermal and chemical pollution of these rivers as the temperature of minewater is relatively constant throughout the year (i.e., it is low in summer and high in winter relative to ambient stream temperatures), and the minewater generally has high concentrations of iron and calcium.

Operation and Maintenance

This technology involves standardized operations similar to those already employed by water supply utilities and in existing mine dewatering systems.

Level of Involvement

This technology is generally implemented at the industrial and local municipal levels.

Costs

In Hungary, the annual maintenance and operation costs are about $8 000.

Effectiveness of the Technology

Where this technology can be used, it provides an effective supplementary source of freshwater which can be used for a variety of purposes, including drinking water supply. Water of lesser quality is often used as industrial process water.

Suitability

The suitability of this technology is limited by the groundwater quality in a particular mine and the relative degree of impairment.

Advantages

Freshwater can be abstracted at low cost to the consumer as an additional benefit of mining activities. Such abstractions can augment water supplies, reduce surface water pollution, and increase mine safety.

Disadvantages

Variations in minewater yield can interfere with the ability of a utility to supply water at a constant rate each day and throughout the year. In addition, in certain instances, minewater may be highly contaminated by heavy metals and other contaminants which make it costly to treat to potable standard. Extreme pH values may also interfere with reuse potential.

Cultural Acceptability

This technology is accepted as a good practice.

Further Development of the Technology

This is a fully developed technology.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

1.10 Computer modelling of the water supply system management

Technical Description

Various computerized management systems have been developed to optimize the operation of water supply systems. For example, the City of Gdynia, Poland, makes use of the OPUS® program for the optimization of its freshwater supply system. Optimization of the water supply system and its components is very important in the planning and management of the system and results in greater conservation and fewer transportation losses of freshwater within the distribution network. A prerequisite for the application of computer-based operations models is a thorough understanding the water supply network and the complete documentation and mapping of each element of the network (including pipe diameter, material, length, year of construction, and friction index). Data on water distribution within the system is also required and can be obtained, indirectly, from marketing bureaus or, directly, from water meter record. Field measurements are also typically needed to verify and calibrate the model.

Extent of Use

Computer-based optimization of water supply networks has been undertaken in only a few urban areas. In Poland, this technology has been implemented in a few cities, including the City of Gdynia, which uses a commercially-available computer program. This program is based upon mathematical graph theory, with the supply points being depicted as nodes within the system connected with arcs. The mathematical modules representing the nodes within the supply system define operational parameters such as distribution areas and water source areas, and length and changes in the diameter or smoothness of the pipe walls. The modules representing the arcs define supply sections, pumps, and valves.

Operation and Maintenance

Skilled engineers and technicians are required for data collection and modelling. Maintenance consists of on-going data collection and entry as water supply networks are upgraded or replaced.

Level of Involvement

This technology is generally implemented at the municipal level by specialist service firms.

Costs

Depending on the availability of adequate data regarding the distribution system and the level of complexity of the model chosen, the cost of this technology may be relatively low, consisting of the cost of the software and staff time. However, should extensive data collection be required or a computer model need to be developed, costs could be considerable, comprising not only the cost of the computer program, field measurements, data collection, and mathematical modelling.

Effectiveness of the Technology

This technology provides a means to optimize both existing and planned freshwater supply systems. Such optimization, in the longer term, can reduce uncertainties in the estimation of demand and provide information on optimal rerouting of supplies in the event of breakdowns in the supply system. This technology is also useful in designing new systems or additions to existing systems.

Suitability

This technology is especially suitable for use in planning large, complex supply systems in urban areas.

Advantages

This technology reduces the problems associated with ineffective distribution within delivery systems (e.g., by minimizing transit times) through an improved understanding of the supply network. This enhances supply effectiveness, reduces power demands associated with pump operations, and lengthens the working life of the infrastructure and water supply facilities. The models can be used to simulate current and future conditions within a distribution system under various conditions, to plan operation and repair activities, and to assess changes in the system and required improvements due to the reconfiguration or enlargement of the network.

Disadvantages

These models are data intensive, requiring well-documented system information that may not be readily available or correct.

Cultural Acceptability

This technology is largely an hidden technology used by the system engineers. However, provided the level of computerization is adequate for the operation of this type of model, systems modelling is well-accepted.

Further Development of the Technology

Better data collection, organization, and data base creation, as a standard procedure in system design, construction and operation, would enhance the ability of municipalities and water utilities to implement this technology effectively.

Information Sources

Dr Marian Kulbik, Sanitation Engineery Unit, Hydrotechnical Department, Technical University of Gdansk, ul. Narutowicza 11/12, 80-992 Gdansk, Poland, Tel. (48-58) 472103, Tel./fax: (48-58) 472421.

1.11 Efficient water use in small hydropower plants

Technical Description

Small hydropower plants often make inefficient use of water resources, and lack automated power generation technologies. To improve efficiency, dispatcher schedules have been worked out for many of the cascade reservoirs used for hydropower production in Latvia, including the Ciriša, Rušonu, and Aiviekstes hydropower facilities. Based upon this schedule, power generation capacity shifts from upstream reservoirs within the cascade to the downstream reservoirs so that the reservoir water levels vary from maximum supply level to minimum supply level in the upstream to downstream direction. This ensures that water is used efficiently and that each reservoir operates over its optimal range of water levels necessary for power generation purposes. For such a scheduled series of shifts in the locus of power production, it is necessary that the management authority have a good understanding of the water regime within the river basin and of the discharges needed for optimal generator operation. In Latvia, there is an established base of hydrological information which makes efficient water use possible within the national hydropower plant network. An important, related issue to the efficient use of water by hydropower generation systems within cascade reservoir series is the minimization harmful effects on environment created by erratic fluctuations in river flows and lake water levels. Use of cascade reservoirs is beneficial in that the construction Costs of impoundments may also be lower.

Extent of Use

Since the early Middle Ages, watermills have been built in Latvia. In the beginning, these activities lacked a strong theoretical basis, and some watermills (and, later, small hydropower plants) lacked sufficient water to operate around the year. While an improved understanding of the hydrology, and technological advances in low head generation units, have overcome the early limitations, there has been a trend in modern times to replace small hydropower generation stations with larger schemes, as has occurred at the Great Plavinas and Riga and the reconstructed Kegums hydropower plants. The larger plants, constructed prior to the introduction of automated control systems, were often more cost effective than smaller, cascade systems give personnel costs associated with their operation. Most recently, however, there has been a shift in this policy, in an effort to achieve energy independence, that favours cascade systems of hydropower generation, in part, because of the high fuel costs associated with thermogeneration plants. To encourage the production of hydropower, the state electricity corporation, Latvenergo, is offering small hydroelectricity producers a premium of 200% in comparison to the prices paid for other sources of energy through the year 2000. Small hydropower plants have been estimated to be able to produce up to 1 000 MW/yr.

Operation and Maintenance

Determination of dispatcher schedules requires the services of both computer personnel and hydrologists. Once the schedule has been determined, regular hydrological monitoring should be undertaken to allow modifications of the regime due to intra- and inter-annual variability in river flows and lake levels. Implementation of the power production schedules requires installation of electronic control systems linking each of the generation plants and water control structures within the cascade. Maintenance is required of the electronic control systems and moving parts, such as water control gates and turbines, that form the structural elements of more effective hydropower generation.

Level of Involvement

Because of the nature of cascade reservoirs and the degree of coordination required, this technology is best implemented by local and regional watershed management administrations in cooperation with the hydropower companies.

Costs

There are no increased costs associated with the infrastructural investments required for conventional small hydropower plants. Indeed, staff and development costs may be lower as fewer operators can control a larger number of small dams.

Effectiveness of the Technology

The efficiency of water use for hydropower generation can be increased from 50% to between 90% and 98% of the annual runoff volume used to generate hydropower. This technology is also effective in regulating unscheduled or erratically-scheduled discharges and makes more efficient use of turbines.

Suitability

This technology is most suitable for use in new and existing, small hydropower plants arranged as a cascade along a water course. Similar technologies could be used for scheduling hydropower generation needs across watershed boundaries.

Advantages

This technology provides for more efficient power production, as well as enhanced water retention within the catchment area that benefits lacustrine and riverine ecosystems.

Disadvantages

The excessive or erratic regulation of water flows in rivers can threaten wetlands and fisheries.

Cultural Acceptability

This technology is well-accepted by citizens who benefit from the improved availability of electricity and water. However, greater acceptance of this technology by technical staff is needed.

Further Development of the Technology

Because of the key role that hydrological data play in this technology, better tools for environmental data collection and assessment are required.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

Dr. hab. Ansis Ziveris, 63 - 33 Bikerniek Street, LV-1059 Riga, Latvia.

2.1 Desalination of minewater

Technical Description

This technology uses solutions of sodium carbonate or sodium hydroxide to precipitate salts from saline minewater. The product of the precipitation reaction is ammonia magnesium calcium phosphate, or FAMC, a polyelemental mineral fertilizer. The process may be modified by fractional precipitation of calcium from the minewater to produce a chalk fertilizer characterized by an high content of magnesium. In the fractional precipitation technique, bromide and iodine are extracted next in sequence. The treated effluent is then discharged to the crystalization chamber, where, apart from many other useful chemicals, pure sodium chloride salt, NaCl, is produced.

Extent of Use

This technology is currently being implemented on an experimental basis by KWK Jaworzno, Poland, where a pilot-scale installation will come online during 1998. The technique was developed as a result of research carried out by the Institute of Agriculture and Soil Sciences in Pulawy, Poland.

Operation and Maintenance

This technology is similar in its operation and maintenance to other chemical processes, which require engineering supervision, process control, media revitalization, and standard monitoring and repair.

Level of Involvement

This technology is intended to be implemented at the industry level.

Costs

While actual costs cannot yet be determined, the investment in the research and development of this technology has been $40 million. The estimated payback period for recovery of this investment is about 10 years, with income derived primarily from the marketing of goods produced during the purification process.

Effectiveness of the Technology

This technology is potentially very effective for removing salts from minewater.

Suitability

This technology has been designed for use by mines with large volumes of highly saline water that require treatment prior to discharge.

Advantages

The most important advantage of this method is that no waste is produced by the process. All of the products, including the desalinated water, can be marketed. In the case of KWK Jaworzno, which discharges 1 725 000 m³/year of saline effluent, marketable goods produced by this technology include 70 000 tonnes of pure sodium chloride, 16 000 tonnes of ammonia magnesium calcium phosphate, and 1 500 tonnes of calcium magnesium fertilizer. In addition, the purified water may be reused for industrial purposes. This process also benefits the environment, by producing an effluent that meets all applicable water quality standards, and the industry, by minimizing the possible fines that could be incurred for failing to meet effluent discharge standards.

Disadvantages

This technology has an high investment cost.

Cultural Acceptability

This technology provides a good solution to an old technological problem, with benefit to the community at large.

Further Development of the Technology

The technology remains experimental and will be tested by KWK Jaworzno, Katowice Voivodship, Poland.

Information Sources

Zdzislaw Kilian, KWK Jaworzno, Grunwaldzka 37, Jaworzno, Poland, Tel. (48-35) 644 02 ext. 5585.

Prof. Tadeusz Kaczmarek, Institute Inorganic Chemistry, Sowinskiego, Gliwice, Poland, Tel. (48-3) 313 051.

2.2 Remediation of polluted groundwater

Technical Description

In situ remedial technologies are emerging from the experimental stage toward the stage of a mature technology. During the last five years, many contaminated sites in Hungary have been remediated using this type of technology. Contaminated sites can only be effectively remediated within a conceptual framework that develops a strategy suited to the infrastructure available at each specific site, with the aim of removing or containing the contaminated soil in order to prevent harmful consequences to other elements of the biosphere. Historically, excavation of large quantities of contaminated soil was the only strategy for soil remediation to prevent groundwater pollution. Sometimes, these soil treatments were accompanied by some form of groundwater remediation. More recently, a comprehensive approach involving groundwater treatment and groundwater protection has been adopted.

In situ physico-chemical remediation, combined with enzymatic biodegradation of hydrocarbons, offers particular advantages for sites where excavation is not feasible, for example, due to presence of buildings and other structures. This type of remedial treatment can be used at production well sites, including horizontal wells, and can be fully automated. Such an approach was used to provide on-site remediation of groundwater at Nagyoroszi following the breakdown of the 'Friendship II' oil transport pipeline. At this site, 2 400 m³ of oil-contaminated soil, with an hydrocarbon concentration of between 2 000 and 16 000 mg/kg, was cleaned over a 6 months treatment period. Soils at this site were cleaned of hydrocarbon contaminants to a depth of 1.5 m to 4.5 m.

Extent of Use

This technology has been used in Hungary and Poland.

In Zahony, located in northeastern Hungary on the Ukrainian border, a large programme of groundwater remediation, expected to extend over a two year period, was recently begun. Because Zahony is an important railway transportation junction between Ukraine and Hungary, and because of the railway guage differences between the two countries, a significant amount of transshipment of goods takes place, including the pumping of liquid hazardous chemicals: hydrocarbons are commonly transferred from the Ukrainian wide-guage tankers to the narrow-guage tankers used in Hungary. Because no groundwater protection measures against the leakage from the pumps and rail wagons were installed, large amounts of potentially dangerous substances have been deposited onto the land surface, where they infiltrated into the sail and the groundwater, since the 1960s. Due to the importance of the Pleistocene aquifers to the freshwater resources of the area, the Hungarian State Railways engaged MSZER Ltd. and ELGOSCAR International Ltd. to identify the extent of the possible contamination and develop a mitigation plan. The extent of the contamination was determined from data gathered from 20 observation wells and other production wells in the vicinity of the station. Well data were collected using a MGSZ geophysical probe. Soils data were also collected from 1 500 sites and examined on-site using an HNU-101 photoionizationic detector and OVA 128 gas chromatograph. These data indicated that 10% of the hydrocarbons were in solution while the balance were present as emulsions; 58% of the hydrocarbons were oils, and 6% were volatile aliphatics, including benzol and ethyl-benzol, which are very soluble and mobile in water. The remedial programme determined for this site used ORS Scavenger pumps to remove free hydrocarbons from both the surface and deeper groundwater abstracted by the production wells. Removal rates range from 1 to 10 m³/m/day of hydrocarbons. The groundwater from the horizontal protection wells is also treated with enzymes, such as ENZIM-MIX®, containing 3% to 6% tenzids, which help to remove particulate hydrocarbons from soil granules. This biochemical process produces carbon dioxide and water from the hydrocarbon contaminants, while air strippers remove the soluble hydrocarbons. Activated carbon filtration is used as a post-treatment.

Operation and Maintenance

This is an highly specialized technology requiring trained personnel and specialist equipment. Operation of this technology is usually undertaken by contractors.

Level of Involvement

This technology is implemented at the level of local administrations and companies.

Costs

Typical costs can exceed $ 1 million, as the remediation of groundwater is a data and time intensive process. The costs include the costs of planning and detailed site investigations ($72 000); equipment, wells, and water treatment systems ($650 000); staff time and monitoring for up to 22 months or more ($400 000); and, remediation of the pumping station site to prevent future groundwater contamination ($30 000), based upon the Hungarian experiences.

Effectiveness of the Technology

This method has proven very effective in the remediation of the kerosene-polluted soils and groundwater at the Ferihegy Airport, Budapest. The treatment efficiencies removed up to 90% to 95% of the hydrocarbon residue from the treated water.

Suitability

Contaminated sites can only be effectively remediated if a conceptual framework is developed that takes into account the infrastructure availability and specific site constraints. However, this technology is potentially suited for use in most areas of the region where hydrocarbon contamination of groundwater is a problem. Nevertheless, prevention of groundwater contamination is always the most appropriate course of action, given the difficulties and expense involved in remedial programmes.

Advantages

This technology provides in situ clean up, which is more energy efficient than other remediation methods.

Disadvantages

This technology is costly, and requires trained personnel to implement.

Cultural Acceptability

The technology is acceptable.

Further Development of the Technology

The technology is fully developed.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

2.3 Lake rehabilitation

Technical Description

Lakes are important resources not only landscape features, but also as recreational venues for fishing, boating, and swimming, all of which are very popular outdoor activities in Hungary. Lakes also serve life-sustaining functions such as provision of flood protection, drinking and irrigation water, and fish. Lake usage must be balanced between the desires of people to exploit lake-based resources and the capacity of the lake to satisfy these desires. Problems arise as a result of limitations on these uses that can reasonably be prevented or corrected with proper management. Thus, lake and reservoir management is an active process that considers how the various components of a lake ecosystem and its tributary watershed work and fit together, and, through this understanding, identifies the effects of various lake management interventions on these different components, both positive and negative.

Lake management techniques include both watershed-based interventions, such as land use planning and pollution control technologies, and in-lake interventions, such as nutrient inactivation. The combination of measures is site specific, and, typically, a number of complementary measures should be used. Based upon in-lake measures, which included nutrient inactivation and sediment removal, hypertrophic S Lake, Hungary, for example, was returned to a eutrophic condition, and it is anticipated that further interventions will restore the lake to a mesotrophic condition. Lake restoration techniques, in this case, made recreational use of the lake possible again.

Extent of Use

Lake restoration interventions are used extensively in Hungary.

Restoration of S Lake, Hungary Shallow ponds are a significant part of the freshwater resource base of Hungary. However, their biological water quality is rapidly deteriorating, especially in areas with great anthropogenic influences. S Lake is a typical shallow lake located close to the City of Nygyh in northeastern Hungary. The lake was a popular holiday resort, but since the 1960s, its water quality has undergone drastic changes due to the rapid cultural eutrophication. As a consequence, bathing has become impossible and the aesthetic value of the resource has decreased. The lake has two basins, one traditionally used for bathing and the other for rowing, and lacks any inflow or outflow. The watershed is about 9 ha and is primarily intensively managed parkland. The eutrophication process within this lake resulted in planktonic algal blooms which were managed using various nutrient inactivation and removal techniques; namely, the addition of 50 g/m³ of alum in the bathing part, and sediment removal and water exchange in the rowing part. By removing the top layer of sediment, the internal nutrient source was reduced and the pond depth increased. These treatments achieved the following results: - The polyhalobic and NaCl-dominated waterbody became alpha-oligohalobic, and, within 2 years, beta-alpha-oligohalobic and Na-HCO3-dominated. - Orthophosphate and total phosphorus concentrations decreased in both parts of the lake. As a result of the alum treatment in the bathing area, the concentrations of phosphorus have remained low, and phosphorus has become the limiting factor for algal growth. - Total nitrogen values also decreased considerably. - Chlorophyll-a concentrations, although different in the three years following the remediation, were lower. - The phytoplankton community has shifted from Cyanophyte and Chlorophyte domination to a more diverse community in which there are fewer Cyanophyte species, and several species of diatoms. - The zooplankton community has also become more diverse, and the overall quantity of zooplankters has decreased.

Operation and Maintenance

Operation and maintenance requirements of lake restoration technologies are similar to those used in other hydrotechnical works. Heavy equipment is often needed, and extensive site investigations are usually required in order to determine the appropriate combination of technologies required to meet the needs of a particular waterbody. As a general rule, control of point sources of pollution close to the lake should be undertaken first, and extended to the entire watershed, and followed by nonpoint source pollution control measures.

Level of Involvement

Lake restoration is usually undertaken at the local administration level.

Costs

Costs depends on the scale of a project and measures selected. Some measures have low cost, such as improved "housekeeping" and public informational programming, and can be implemented by individuals and volunteers. Other measures, such as alum treatments and aeration or land use planning, are broader in scope and require governmental action to implement effectively.

Effectiveness of the Technology

These technologies have been successful in restoring natural water ecosystems. However, it is essential that the source of the contamination be identified and controlled to the extent possible if the restoration is to have long-term success.

Suitability

Lake restoration techniques may be used throughout the region. These technologies are most suitable for use on waterbodies with developing eutrophication problems.

Advantages

Lake restoration techniques can enhance recreational and other use of a lake.

Disadvantages

No disadvantages have been identified. However, it is important that the causes of the pollution be correctly identified for the correct combination of restoration techniques to be applied and for the programme of lake restoration to be successful in the long-term. It should be noted that not all techniques are immediately effective; techniques such as biomanipulation may have a considerable lag time before their effects are fully apparent.

Cultural Acceptability

Lake restoration techniques generally create no cultural problems. However, citizen involvement is usually both a driving force behind lake restoration projects and an essential element of such projects to ensure their sustainability. Hence, public information is an important component of lake restoration programmes that is often overlooked.

Further Development of the Technology

Most lake restoration techniques are fully developed. However, the ability to identify and forecast with certainty the impacts of individual techniques should improve as experience in lake management increases.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

2.4 Biofiltration

Technical Description

Technology of biofiltration is based on the controlled use of the ecological characteristics of common mollusc species, such as the freshwater mussel (Dreissena polymorpha). Freshwater mussels are natural filter feeders, which effectively and efficiently filter organic and inorganic matter from the water. Freshwater mussels and other water sedentary organisms (such as bacteria, rotatoria, sponges, coelenterates, infusoria, and crustaceans) which constitute the periphyton can, on a specially prepared, artificial bedding with an open weave, create a biological membrane that can effectively purifying water contaminated with organic matter, bacteria, and other biogenic elements.

Providing the mollusc species with appropriate bedding on which other organisms are also able to grow results in the creation of a "living biofiltration system" that is both self-reproducing and highly efficient in reducing concentrations of pollutants in water. For example, such a biofiltration system, or biological membrane, was installed in Raciaz Lake during 1994. This system consists of a collector panel with 50 biofiltration units. Each unit is a simple sack made of suitable material with a float inside (typically, a sealed plastic bottle). Collector panel is fixed by ropes anchored to concrete weights placed on the lake bottom. Native lake organisms, naturally occurring in the lake water, settle (as larvae) on the sacking and grow.

Extent of Use

This method has been field tested at a few natural sites in Bory Tucholskie (Raciaz Lake, Suszek), in the northern part of Poland, and there are two known full-scale applications of this technology; one, used for treatment of waters discharged from a salmon trout hatchery and fish farm, at Laska Biala, Mytlof, and the other, used to purify contaminated water, at Raciaz Lake.

Operation and Maintenance

Most of the operation is undertaken during the initial stage of preparing the artificial bedding and positioning the unit within the waterbody. Subsequently, some limited control and repairs must be completed. Because the technique uses biological material that naturally occurs in inland waters, the succession of molluscs on the bedding is fully natural process which does not require any intervention. Materials for the bedding are simple and easy to obtain (some waste materials, such as the plastic bottles used for floats, can be utilized).

Level of Involvement

This technique is usually implemented at the local administration level.

Costs

The technology has very low costs. Most construction, including the preparation of the bedding (using waste materials), can be accomplished with minimal labour and materials costs.

Effectiveness of the Technology

The filtration capacity is a characteristic feature of every mollusc species. Freshwater mussels are the most efficient filter feeders in central European inland waters, with a single freshwater mussel (about 3 cm in diameter) filtering around 100 ml/hour. Because of high density of mollusc population (up to a few thousand per m²), the volume of water filtered is very large. Freshwater mussel populations living on a biological barrier with an area of 100 m² can filter between 500 and 28 000 m³/day and absorb up to 5.5 g of phosphorus and 11.5 g of nitrogen (depending on biological activity).

Suitability

The method is suitable for use in most natural and artificial waterbodies, and can be applied as a polishing step at existing wastewater treatment facilities. It is especially useful in areas with low to moderate environmental impacts. [Caution: Non-native species should not be introduced into waterways.]

Advantages

This biohydrotechnology does not impact natural movements of water within a water body, and, thus, appears to be a useful means for upgrading water quality and ecological value using native aquatic fauna and flora. Because of the flexibility of the technology, and the possible wide range of modifications, it could be used in most types of waterbodies. The technique should be effective over a range of pollutant types. The technology has a very low cost, can be implemented in a phased manner, and is highly effective and efficient.

Disadvantages

In case of chemically polluted waters, persistent pollutants like heavy metals may interfere with the biological utilization of contaminants.

Cultural Acceptability

Method is based on natural ecological processes and is fully acceptable.

Further Development of the Technology

This method is experimental and some research is needed to optimize the design specifications and verify its efficiency, especially under a range of pollution conditions.

Information Sources

Prof. Dr. hab. Roman Gondko, University of L Department of Biology and Earth Sciences General Biophysics Unit, ul. St. Banacha 12/16, 90-237 L Poland, Tel. (48-42) 35 44 74, fax: (48-42) 35 44 73.

Janusz Krupanek, Institute for Ecology of Industrial Areas, ul. Kossutha 6, Katowice, Poland, Tel.(48-3) 1546031, fax: (48-3) 1541717, e-mail: jan@amnesia.ietu.us.edu.pl.

3.1 Ozone (electro-plasma) wastewater treatment

Technical Description

Ozonation, or electro-plasma wastewater treatment, is designed to disinfect and purify natural waters and wastewater. Electro-plasma treatment removes radionuclides, oil, surfactants, fats, dyes, heavy metals, and other compounds, both of organic and inorganic origin, from the treated waters. Plants currently in operation in Ukraine have a through-put of 500 m³/day, and are designed to be expanded by the addition of further 500 m³/day units. The units currently in use have an areal requirement of 8 m² for the wastewater treatment unit, and an additional 4 m² for the drinking water unit. The wastewater treatment units have a power demand of 0.4 to 1.0 kW/m³, and a mass of 1 000 kg. The drinking water module has a mass of 500 kg.

The Electro-plasma wastewater treatment systems used in Ukraine comprise an impulse electromagnetic activator; an counter-turbine ejector; an electro-hydro-gas-impulse reactor; an electro-gas-ionic stabilizer; and, a control station. Water (or wastewater) undergoes primary mechanical treatment and comes to the impulse electromagnetic activator (EMA), where it undergoes further treatment by pulse electromagnetic field. This treatment increases the solubility of gases, reduces the scaling capacity, and increases the sorption capacity of suspended matter, increasing coagulation rates by up to 45%. The effluent then flows into the counter-turbine ejector, where, rotating around its axis, the flow pattern changes from laminar to turbulent flow. Simultaneously, the effluent is injected, through the ejector, with ozone, which oxidizes organic compounds and bacteria. The gas-liquid effluent is in a state of slow cavitation (about 7 W/cm² intensity) when it enters the electro-hydro-gas-impulse reactor (EHGIR). There, the effluent undergoes treatment with pulsed electric discharges which, as a result of the impact of short shock waves (1 to 50 ms at pulse pressure about 20 000 kgf/cm²), increases the solubility of ozone-enriched air by more than 30 times, forming a suspended matter flocculant that is not less than 0.2 mm in diameter. The effluent is also subjected to UV-irradiation to remove bacteria and other pathogens. The flocculants are removed by electro-coagulation and flotation in the electro-gas-ionic stabilizer (EGIS), decreasing the COD, and removing oil and grease. Chloride ions are transformed into chlorine during this stage of the treatment process, providing a further element of pathogen protection prior to the discharge of the treated effluent.

Extent of Use

Electro-plasma treatment, which produces and effluent that complies with international quality standards, has been implemented in industrial facilities in Finland, Germany, Czech and Slovak Republics, Cyprus, Sweden, Israel, and other countries. In these various applications, the technology has been used to produce water for drinking water supply (by removing radionuclides, hardness, iron, hydrogen sulfide, and bacteria), industrial wastewater treatment (by removing detergents, surfactants, oil, dissolved iron, chromium [Cr⁶⁺], and radionuclides), agricultural wastewater treatment, and specialized treatment of water for medical purposes.

Operations and Maintenance

Operation and maintenance of these units requires skilled labour. Typically, both an engineer-technologist and control operator are required.

Level of Involvement

This technology is usually implemented at the local administration or industrial levels.

Costs

The cost of a 500 m³/day unit is $250 000. Increased capacity is achieved through combinations of these unit. There are various versions of this technology; the EPOS® system, used in Ukraine, is proprietary in nature (International Patent No. WO92-12933 of 06.08.1992).

Effectiveness of the Technology

This technology has proven effective in a range of treatment situations.

Suitability

Electro-plasma treatment technologies are suitable for numerous operations, and can be easily added onto existing treatment systems. The technology is well-suited to producing a product water that may be recycled on-site or to produce additional final product waters. Ozonation has a further advantage in that it does not require the effluent to be treated with alum, polyacrylamide flocculant aids, lime, chlorination, or other reagents which require replenishment, preparation, and additional treatment water consumption.

Advantages

Ozonation is a reagent-free purification method that is up to 100% effective in removing bacteria and other contaminants, including radionuclides, heavy metals, nitrites, and nitrates, with relatively low power consumption rates (0.4 to 1.0 kWh/m³ of wastewater, depending on concentration of contaminants). The technology is well-suited to providing process water for reuse. The process can be highly automated, and outputs can be tailored to specific requirements.

Disadvantages

The technology is complicated, requiring specialized staff and services.

Cultural Acceptability

This technology is generally considered to be a very innovative technology, relative to the more traditional technologies used in the region, and is not yet widely accepted as an alternative to the traditional methods. However, the product water is culturally acceptable.

Further Development of the Technology

The technology is fully developed.

Information Sources

Dr Vladimir Demkin, Ministry for Environmental Protection and Nuclear Safety of Ukraine, 5 Khreschatyk St., Kyiv-1, Ukraine, Tel./fax: (380-44) 228 0786, fax: (380-44) 229 8050, e-mail: demkin@mep.freenet.kiev.ua.

3.2 Denitrification of wastewater

Technical Description

This technology is based upon biological denitrification and thermal decomposition of the ammonium carbonate. The phases and operations of the process are neutralization of nitrate and ammonia enriched waters (waters containing NH₄NO₃ and NH₃) with carbon dioxide (CO₂), followed by biological denitrification in an anaerobic activated sludge media. During this process, pH corrections are made with the CO₂, and the biomass is stirred at the same time. The organic carbon source for bacterial growth is contained within the wastewater. Subsequently, the effluent is subjected to temperatures of 90°C to 95°C, at which temperatures thermal decomposition of ammonium carbonate occurs. Gases containing ammonia (NH₃), CO₂, nitrogen (N₂), and water vapour, may be recycled into fertilizer production where they can be converted from the calcium nitrate, Ca(NO₃)₂, phase into ammonium nitrate, NH₄NO₃.

Extent of Use

This technology is used in Romania.

Operations and Maintenance

Operation of this technology requires provision of biological denitrification in a treatment system with two compartments, having an internal connection which allows the biomass to be stirred by the hydrostatic pressure differentials created by the CO₂ used for pH corrections during the denitrification process, which is injected under pressure. The second element of the process is a column for ammonium carbonate, (NH₄)₂CO₃, decomposition, and NH₃ and CO₂ stripping. The activated sludge portion of the treatment process, if lacking adequate organic carbon for bacterial growth, may require addition of methanol as a carbon source. The system requires specialist operating personnel.

Level of Involvement

This technology is implemented at the municipal and industrial levels.

Costs

The estimated cost of a purification plant treating wastewater at a rate of 200 m³/h is approximately $6.1 million. Approximately $5 million of this cost is incurred in plant construction.

Effectiveness of the Technology

This technology is best suited for treating wastewater flows of 200 m³/h, having a contaminant composition 5 000 mg/l NO₃^- and 2 500 mg/l NH₄⁺. For wastewaters meeting these characteristics, the technology is highly efficient, and produces a treated effluent with a contaminant concentration of less than 50 mg/l NO₃^-. In comparison with the classic nitrification-denitrification and ammonia stripping-denitrification processes, this technology allows the elimination of the nitrification phase and the corresponding reductions in the consumption of energy, oxygen, and sodium bicarbonate (Na₂CO₃); the elimination of the use of sodium hydroxide (NaOH) as a free NH₃ source in the stripping process; the elimination of the use of sulphuric acid, H₂SO₄, as a neutralizer in the denitrification process and avoids pollution of the water with sodium, Na⁺, and sulphate, SO₄^2-, ions as a consequence; and the reduction of energy consumption for mechanical stirring of the biomass in the bioreactor by using CO₂ pressure.

Suitability

This technology is suitable for use in industries treating wastewater contaminated with nitrogen fertilizers.

Advantages

This technology may be extended to provide for reuse of the product water and byproducts. It may also be modified to achieve heavy metal removal.

Disadvantages

No disadvantages have been identified.

Cultural Acceptability

The technology is culturally acceptable as an improved wastewater treatment technique.

Further Development of the Technology

The technology is fully developed.

Information Sources

ICPEAR (Institutul de Cercetari pentru Epurarea Apelor Reziduale - Research Institute for Waste Waters Treatment), Sos. Pandrui nr 90-92, sector 5 Bucuresti, Bucharest COD 76231, Romania, Tel./fax: (40-1) 410 67 16.

3.3 Treatment of the wastewater from a coking plant

Technical Description

The technology usually includes, as principal phases, the gravity separation of tars and oils, ammonium stripping, and a two stage biological purification process to remove especially phenols and sulphocyanides. Possible modifications of the technology could include breaking down colloids by cationic polyelectrolyte treatment, improved removal of phenols by introducing of a biooxidation phase, and ozone treatment for the removal of traces of cyanide and colour (the ozonation technology is described above). Pretreatment with bleaching earth is recommended prior to ozonation to minimize the amount of ozone required.

Extent of Use

This technology has been applied in Romania.

Operations and Maintence

This technology makes use of readily available wastewater treatment components, including biofilters, ozone production plant, and measurement and control equipment, and commonly available reagents such as cationic polyelectrolytes. The system requires moderately skilled staff to operate.

Level of Involvement

The technology is usually implemented at the local and/or community level. However, due to the cost of the equipment, (partial) external financing may be necessary.

Costs

The cost of this technology is approximately $3 to $5.5 million, depending on import requirements and the size of the plant.

Effectiveness of the Technology

The technology is highly efficient and produces an effluent of consistent quality, which meets or exceeds the Romanian quality requirements for discharge into surface rivers in the III-rd category. Pilot scale plants of 5 m³/h capacity are in operation and a 135 m³/h capacity industrial plant is being completed.

Suitability

The technology has been developed for application in the treatment of wastewater from the coking industry, although other applications may be possible using modifications of this technique.

Advantages

This technology is well suited for treating complex wastewaters contaminated with tars, oils, phenolic compounds, ammonium, sulphocyanides, cyanides, and other pollutants that are difficult contaminants to treat using traditional wastewater treatment methods.

Disadvantages

There are no known disadvantages.

Cultural Acceptability

This is a acceptable wastewater treatment technology.

Further Development of the Technology

The technology is fully developed.

Information Sources

ICPEAR (Institutul de Cercetari pentru Epurarea Apelor Reziduale - Research Institute for Waste Waters Treatment), Sos. Pandrui nr 90-92, sector 5 Bucuresti, COD 76231, Romania, Tel./fax: (40-1) 410 67 16.

3.4 Food industry wastewater treatment

Technical Description

This technology was developed to treat wastewater from the edible oil industry. The technology is modular, and the treatment module is suitable for continuous or batch operating regimes, depending on the particular conditions at the plant concerned. The major advantage of the modular system is the possibility of installing it in close proximity to the pollution source. The module operates in three stages: precipitation, coagulation-flocculation, and polyelectrolyte treatment. The effluent initially goes through a gravity separator that removes the floatable fatty oils. The wastewater entering the second stage of the treatment process, therefore, contains only those fatty materials in emulsion, which are separated in two stages of chemical treatment. The first stage loosens the oil-water bonds, while the second stage separates the oil drops from water. A finishing stage provides process control and improvement of the effluent to meet water quality discharge requirements.

Extent of Use

This technology is used in Romania.

Operation and Maintenance

The technology uses well known principles of wastewater treatment, and is easy to build and maintain. The reagents used are common water treatment chemicals which are readily available in the region. Treatment plants using this technology can be operated and maintained by one or two trained workers.

Level of Involvement

The technology is implemented at the local community or individual industry levels.

Costs

The costs depend on the quality of water required to be achieved and number of stages of treatment necessary to achieve the required quality.

Effectiveness of the Technology

Table 3 shows the typical improvement in effluent quality that can be achieved with this technology. The technology is capable of treating food industry wastewater to an acceptable standard for discharge to natural water courses.

Suitability

This technology has been proven to be effective in purifying wastewater contaminated with fatty oils, and, as such, is suitable for use in treating wastewater from the manufacture of margarine, wastewater from the meat products industry, and wastewater from the dressings production plants.

TABLE 3. Improvements on Water Quality Achieved with Wastewater Treatment.

Parameter	Influent Wastewater Quality	% Reduction Achieved
COD-Mn	820 - 1 200 mg O2/dm³	90%
COD-Cr	4 200 - 5 200 mg O2/dm³	80.4%
BOD5	2 600 - 3 600 mg O2/dm³	90.8%
Chloride (Cl-)	98.3 - 112 mg Cl/dm³	--
Soluble substances in petroleum ether	812 - 1 112 mg/dm³	91.3%
Total dried residue	1 975 - 2 875 mg/dm³	94.5%

Advantages

The technology can be maintained at local industry level, and may be adapted to suit the requirements of specific industrial operations. The technology uses readily available reagents, which are unique to each stage of the treatment process. Depending on the particular situation, the stages may be combined or partially suprimated. A direct advantage of this technology is the recovery of the fatty materials which might be reused. In addition, there are two indirect advantages; namely, the elimination of a major portion of the pollutant load from the effluent stream, and a decreased oil and grease load on the purification plant.

Disadvantages

There are no known disadvantages.

Cultural Acceptability

This technology is acceptable as a wastewater treatment technique.

Further Development of the Technology

The technology is fully developed.

Information Sources

Anca Manea and Alexandra Orlescu, Food Chemistry Institute, Str Girlei 1, sector 1, Bucharest, Romania, Tel. (40-1) 679 20 40.

3.5 Slaughterhouse wastewater treatment

Technical Description

Slaughterhouse effluent is usually high in organic contaminants. The BOD₅ oscillates between 1 500 and 2 200 mg/l or higher, which typically creates problems for traditional purification plants. To overcome these problems, this technology uses a chemical coagulation technique to precipitate the organic materials from the wastewater stream. The technology uses flow equalization tanks equipped with pneumatic agitators, chemical dosing systems, and a separator. In the first stage, a continuous chemical injection system adds an acidic coagulating agent known as T.I. In the second stage, a continuous chemical injection systems adds lime milk. After an initial T.I. mixture reaction time of 5 minutes (at pH = 4.4) in the first stage reaction tank, the effluent is transferred to the second stage reaction tank where it is neutralized (to pH = 7.0) by the injection of the lime milk. In the third stage, the effluent is placed in a vertical reaction column where separation of the coagulated sludge and supernatant water takes place. The supernatant is then siphoned off for further biological purification in aerated activated sludge tanks. Aeration is achieved with surface turbines. The sludge in the chemical stage separator, together with the excess activated sludge, is dehydrated under vacuum in rotary filters.

The T.I. coagulating agent is prepared daily from ground metallurgical slag and diluted sulphuric acid, H₂SO₄. The residual, exhausted slag is neutralized with lime milk, and, together with the dehydrated sludge, is used as fertilizer for agriculture. The principle active elements of this coagulating agent are the ferric sulphate and silicic acid which act as accelerators of flocculation.

Extent of Use

The technology is used in Romania.

Operation and Maintenance

The technology uses well known principles of wastewater treatment, and is easy to build and maintain.

Level of Involvement

This technology is implemented at the individual company level.

Costs

The costs depends on the desired discharge quality of the treated wastewater and number of stages need to achieve the required effluent quality.

Effectiveness of the Technology

This technology can achieve about an 80% reduction in BOD₅ in the chemical stages and a further 80% reduction in the biological stage. The overall purification efficiency of the technology was over 99% and achieved between 99.5% and 99.6% effectiveness at times. The product effluent was clear, colourless, and free of odours, with a BOD₅ of about 5 to 10 mg/l.

Suitability

This technology is suitable for treating slaughterhouse effluents.

Advantages

This is an highly efficient method of waste water treatment.

Disadvantages

No known disadvantages have been identified.

Cultural Acceptability

This technology is accepted as a wastewater treatment technology.

Further Development of the Technology

Technology is fully developed.

Information Sources

Nikolic Vasilie, Food Chemistry Institute, Str Girlei 1, sector 1, Bucharest, Romania, Tel. (40-1) 679 20 40.

3.6 Treatment of wastewater the sugar industry

Technical Description

The sugar industry is an important consumer of both drinking and industrial waters used in the refining process. Wastewaters produced have an high organic load and, initially in the refining process, also have an high particulate load. Thus, treatment of these wastewaters requires a process that combines mechanical, chemical, and biological treatment measures. The principle element of the purification process is based upon the aerobic activated sludge technology with one or more aeration stages.

The raw wastewater entering the treatment plant is mechanically treated (primary treatment) to remove coarse particulate, then conveyed to the primary separator which removes suspended particulate through sedimentation, and, finally, mixed with the recirculated, activated sludge in the aeration tank. The activated sludge is separated from the treated effluent in the secondary separator, and is recirculated to the aeration tank where it is again mixed with the wastewater entering the plant. Excess sludge is removed from the circuit at this time. Following this treatment, the treated effluent is discharged from the plant. This product water (the effluent from the treatment plant) is thus free of the major part of the degradable organic substances.

The principle factors which determine the ability of the purification process to remove organic pollutants, and, in that way, the quality of the effluent of the plant, are the reaction time between the wastewater and the biomass in the aeration tank, the type and speed of reactions that take place during wastewater treatment, and the concentration of the contaminants in the wastewater and the biomass in each moment during the reaction. Thus, for optimal treatment using aerobic activated sludge treatment, it is important that the inflowing wastewater have certain characteristics that make it treatable using this technology; namely, the wastewater must be biologically treatable (biodegradable), contain essential plant nutrients such as nitrogen and phosphorus (if these two elements are lacking, as in the wastewater from the sugar industry, they are added as urea and orthophosphate in the aeration tanks in order to ensure a C:N:P ratio of 100:5:1), be between 7.0 and 8.5 pH units (maintained using chemical reagents), and free of substances that inhibit the growth of aerobic microorganisms. In addition, the waste stream should be as constant as possible, in terms of both quantity and composition, in order to avoid the shocks that can negatively influence the purification process and the yield. Aerobic conditions must be maintained in the reactors (the lack of oxygen results in mineralization of the biomass), which also keeps the biomass in suspension.

In Romania, sugar processing wastewater is collected and transported through pipelines (preferable underground ones because the processing takes place during the cold season) to a collection facility, where it is passed through a sand separator to remove contaminants like sand, stalks, leaves, etc. From the sand separator, the wastewater passes by gravity flow to the primary separator, which is equipped with hydraulic devices for collecting the separated sludge and the foam. The separated sludge is removed, drained, and dried in sludge drying beds. The water passes from the separator into the first stage aeration tank, which is equipped with devices for aerating the effluent and adding the nutrients in order to promote the growth of active sludge bacteria which metabolize up to 75% of the organic pollutants in the wastewater. In the next phase, the water passes into the second stage separator from which the excess sludge is pumped to the drying areas, and the supernatant is pumped into an aeration tank, which further purifies the effluent by removing up to 95% of the initial organic load. The sizing of the aeration tanks should be such that they are adequate to handle the hydraulic charge and the appropriate concentration of the recirculated sludge, and provide sufficient aeration and sludge contact time.

From the aeration tank, the water passes in devices that collect the sludge, which is dried in sludge stabilization ponds, and remove the foam.

Extent of Use

This technology is used in Romania.

Operation and Maintenance

This is a locally available technology, which requires specialist operators. Nevertheless, the technology can be maintained at local industry level.

Level of Involvement

This technology is implemented at the local industry level.

Costs

The estimated cost of a facility capable of treating sugar industry wastewater at a rate of 300 to 350 m³/hour is approximately $12 million.

Effectiveness of the Technology

The technology removes 95% to 98% of the organic contaminants in sugar processing wastewater.

Suitability

The technology is suitable for all types of wastewater treatment where the wastewater has an high, predominantly organic, pollutant load which is biodegradable.

Advantages

This is an highly efficient means of wastewater treatment.

Disadvantages

No disadvantages have been identified.

Cultural Acceptability

This is an acceptable wastewater treatment technology.

Further Development of the Technology

When the technology is applied to the treatment other effluents, there is a need for a short study to determine the bioreaction conditions and contact times for each step.

Information Sources

Isvoranu Ioan, Food Chemistry Institute, Str Girlei 1, sector 1, Bucharest, Romania, Tel. (40-1) 679 20 40.

3.7 Lemna-based wastewater treatment system

Technical Description

Lemna, or duckweed, is a small, green plant that grows on the water surface, and is especially prevalent in conditions that are rich in nitrogen. When Lemna is used for wastewater treatment, the plant, which floats on the top of the wastewater, uses the nutrients and other organic substances contained in it. It grows very fast, is not very sensitive to changes in climate or wastewater quality and quantity, and can be found all over the world. A Lemna-based treatment system can be created in new artificial ponds or can be introduced into existing lakes within a couple of weeks. The ponds can be planned as individual treatment areas or can be joined together to reach the necessary treatment efficiency. The depths of the ponds should be between 1.2 m and 3.6 m.

Before discharge into the duckweed pond, bulk materials, sand, and grit must be removed by screening and preliminary settling in a grit chamber, and the clarified effluent may received further treatment in anaerobic, facultative, or aerobic ponds. In some cases, to ensure a final dissolved oxygen concentration of over 5 mg/l, cascade aeration could be considered. After discharging the treated effluent into the Lemna ponds, the resultant plant biomass must be collected with special harvesting machines. This biomass has high protein and mineral contents, and, after composting, is usable in agriculture without restrictions.

Figure 3. Biology of a Lemna pond.

Extent of Use

This technology has limited application in Poland and Hungary.

Operation and Maintenance

Maintenance of the system is simple; namely, maintenance of facilities, biomass harvesting, and composting. It does not require highly trained personnel, and uses predominantly natural processes. [Caution: Non-native species should not be introduced into waterways.]

Figure 4. Construction of a Lemma treatment plant.

Level of Involvement

This technology is implemented at the local community level.

Costs

Costs are generally low, but include the cost of land, construction materials, and labour.

Effectiveness of the Technology

This technology naturally removes not only BOD₅ but also phosphorus and nitrogen at an affordable price. Retention time, depending on the removal efficiency desired, is between 15 and 30 days. Average effectiveness is 90% to 95% removal of BOD₅ and suspended matter. Reductions in nitrogen average 25% and 80% for phosphorus.

Suitability

This technology is suitable for the treatment of household wastewaters in medium sized municipalities, pert-urban districts, and rural areas.

Advantages

Treatment can be carried out in natural or artificial existing ponds, and the treated water can be reused for irrigation. The biomass produced makes a good fooder for animals or compost. The energy demand is minimal, as the technology uses natural energy sources.

Disadvantages

The disadvantage of this system is its dependence on favourable climatic conditions. During winter or cold weather, the treatment process is slowed down. In this situation, it is necessary to create additional storage to handle the same volume of wastewater as during warm weather.

Cultural Acceptability

This is an acceptable wastewater treatment technology.

Further Development of the Technology

The technology is well tested and fully developed.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

3.8 Land treatment using trees

Technical Description

Land treatment is defined as the controlled application of wastewaters to the land surface to achieve a specified degree of treatment through natural physical, chemical, and biological processes within the soil-plant-water matrix. This method includes the utilization of nutrients in the wastewater for wood production and groundwater recharge. In Hungary, the most extensively used irrigation method is the "slow rate" process using poplar trees, while, in Poland, willow trees are used. Both trees use the nutrients and evapotranspirate the wastewater very efficiency. The average annual loading rate of the slow rate process is 2 to 2.5 m/year. Soils ranging from clay loams to sandy loams are suitable for irrigation. Soil depths should be at least 0.3 m of homogeneous material. If the site drainage is poor, underdrains may be required. Wastewater is discharged into small flooding basins or irrigation furrows, which are located between two rows of trees, by various means including gravity flow and pumped flow from primary treatment plants. The primary treatment is provided by bar screens and calcium-hydrate dosing.

Figure 5. Flow chart of the land treatment plant.

Extent of Use

This technology is extensively used in Hungary, and is coming into use in Poland at a few sites.

Operation and Maintenance

The system does not require highly trained personnel for maintenance. Maintenance services include cutting the old trees, plowing, flooding the basins, etc.

Level of Involvement

This technology is implemented at the local administration and household levels.

Costs

Given the need for pre-treatment of the effluent applied to the forest plantations, the cost of a 500 m³/d capacity plant is approximately $200 000. Wood sales should offset a portion of this initial investment cost.

Effectiveness of the Technology

The technology can produce an expected average quality effluent with less than 2 mg/l BOD₅, 1 mg/l suspended solids, 0.5 mg/l ammonium-nitrogen, 3 mg/l total nitrogen, 0.1 mg/l total phosphorus, and no fecal coliforms. The treatment efficiency is controlled by the application rate, and the process should be monitored by sampling and analysing the surface drainage and well waters.

Suitability

This technology is suitable for treating municipal wastewater, wastewater from solid waste disposal sites, wastewater plants, and contaminated floodwaters. This method is also acceptable for use by small settlements (to treat night soil and sewage water) and for treatment of agricultural wastes (e.g., liquid manure, wastewater from the food processing industry, etc.)

Advantages

This technology not only results in water savings, by replacing freshwater used to irrigate tree plantations, but also produces an economic return on the marketable woods. It has a low energy requirement and does not require sludge. The tree systems are easy to create and inexpensive to maintain.

Disadvantages

Wastewater applications may result in possible groundwater contamination. The ability to irrigate the wastewater depends on both soil and climate conditions, and may require additional storage to be provided during winter and periods of cold weather. The technology requires a large area of land, which may need to be buffered from surrounding land uses by a protective zone due to odour emissions and similar environmental impacts.

Cultural Acceptability

This is an acceptable wastewater treatment technology. However, it may not be acceptable for people whose estates border upon treatment area.

Further Development of the Technology

This is a fully developed technology.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

3.9 Hydrobotanical or wetland treatment

Technical Description

Hydrobotanical treatment is based upon the natural water purification ability of wetland vegetation. Hydrobotanical treatment requires mechanical wastewater pretreatment, which is typically provided by means of a three-chamber flux settlement tank made of plastic (for ease of transport and construction). The biological treatment unit is specifically designed for each individual case, but typically can consist of ponds populated by various bulrushes, reeds, and cattails; land-based vegetative (cattail) filters with lateral and gravity-fed wastewater applications; or, cascades populated with bog vegetation (e.g., bulrushes, reeds, cattails, and willows). It is also possible to install a wastewater recirculating system for complex nitrogen removal. The plant beds generally consist of shallow trenches, shaped to conform to the land slope (which should not exceed 1 % to 2%) and lined with an artificial (having a membrane thickness of at least 0.5 mm) or natural (e.g., clay or poorly drained loam) isolation lining. The trench should be about 0.5 m to 0.6 m in depth and filled with well drained grit. Wastewater is applied by distribution pipes equipped with a system of tees to ensure sheet flow across the vegetation bed. The level of wastewater is kept under loading bed surface by controlling the rate of application. Treated waters are released through a drainage, positioned perpendicular to the direction of wastewater flow. There are usually two vegetative filters operated as a dual system. The reeds used in combination with the other vegetative elements provide oxygen translocation to the rhizosphere, allowing for nitrification and decomposition of organic matter, maintenance of proper hydraulic conditions, and, in winter, good thermal insulation.

The technology is capable of removing BOD₅ through aerobic and anaerobic decomposition and sedimentation; nitrogen through nitrification and denitrification, and vegetative utilization; phosphorus through vegetative utilization and accumulation in the soil; and, bacteria through sedimentation, filtration, and natural degradation as a result of exposure to unfavourable environmental conditions. The biological treatment can be enhanced by dosing with bioadditives to reduce odours near the mechanical treatment plant, BOD₅ and the amount of wastewater sludge. Sludge occurs as a result of the reduction of organic solids, and can interfere with the movement of the wastewater through the canals, pipelines, and outlet.

Treatment of this kind requires suitable terrain, which allows natural laminar flows. The treatment area required is 10 to 12 m²/person served. For installation purposes, an area with a flat surface, having a shallow slope (1% to 2%) in the direction of outlet and a sandy undersoil, is recommended. Such terrain permits the system to be operated by gravity; however, in cases where the recirculation of wastewater or unfavourable relief occurs, power requirements average about 1.5 kW.

Extent of Use

This technology has been used on a limited basis in Poland.

Operation and Maintenance

These systems have few requirements for their operation and maintenance. The materials needed for their construction (e.g., pipelines, interunits, well regulation controllers, moulders, drainage systems, PVC couplings) are readily available in the region.

Level of Involvement

This technology is implemented at the level of a local administration, generally as a public works project.

Costs

The investment cost is about $40 to $60/per inhabitant, depending on land relief, soil conditions, quality of the wastewater to be treated, size of the wastewater treatment plant required for pretreatment of the effluent, and the availability of filter bed materials. Operating costs in a gravity-fed scheme are low, including the cost of periodic control of flow rates, removal of sediments (once per year), and the eventual replacement of vegetation.

Effectiveness of the Technology

The technology can produce an effluent with a BOD₅ of 30 mg O₂/dm³, an organic matter content of <50 mg/dm³, a total nitrogen concentration of <30 mg N/dm³, and a total phosphorus concentration of <5 mg P/dm³.

Suitability

Treatment facilities of this kind are suitable for use in rural areas, small settlements, and recreational centres, and as a secondary treatment in conventional wastewater treatment plants. Better performance of this technology is achieved in the southern parts of Europe than in north due to unfavourable climatic conditions in the latter; in winter, the biological processes are slowed down.

Advantages

This technology can achieve an high rate of BOD₅ and suspended matter reduction (up to 90% to 95%), as well as nitrogen and phosphorus removal. It is simple and offers a reasonable degree of treatment at a competitive price. The technology has few requirements for operation and maintenance, and, in most cases, have no or low energy demands. The wetland systems can enhance the natural landscape and are generally harmless to the environment. There is no need for protection zones because the treatment occurs in the undersoil.

Disadvantages

This is a land-intensive technology.

Cultural Acceptability

For climatic reasons, this technology is not well accepted as a wastewater treatment technique in Poland.

Further Development of the Technology

There is a need for to enhance this technology by improving the capacity of the biogenic elements to effect pollutant removal, and the winter performance of the technology.

Information Sources

Contacts

Zaklad Gospodarki, Wodno-sciekowej, FIN-SKOG Geomatics International, ul. Jaskowa Dolina 59, 80-286 Gdansk, Poland, Tel./fax: (48-58) 476771.

Bibliography

Ministry of the Environmental Protection, Natural Resources and Forestry 1993. Water Protection and Waste Water Treatment. Ministry of the Environmental Protection, Natural Resources and Forestry, Warsaw.

3.10 Activated sludge wastewater treatment

Technical Description

Primary treated sewage effluent is conveyed to an equalizer-aeration tank that is provided with oxygen by deep aerators fed by air blowers forcing air into the pipelines. During aeration, an aerobic microorganism uses the pollutants contained within the wastewater as a nutrient source. From the aeration tank the wastewater flows into a final sedimentation compartment, where the liquid and activated sludge are separated. From this compartment, the purified water is discharged into a receiving waterbody, usually by means of gravity. From the bottom of the settlement tank, a pump recirculates the activated sludge back into the aeration tank. The electrical power required by the technology is about 20.4 kW.

The EGALAIR® system is one example of a specialized activated sludge-based treatment process. It is an Hungarian development, and is a compact, biological sewage water treatment plant based on a method of total oxidation. All of the compartments are included within one, steel construction unit.

Extent of Use

In Hungary, this type of sewage treatment system was built at the Village of Tarpa in 1992, with a daily capacity of 100 m³ of sewage and 30 m³ of sludge from septic tanks (night soil). This capacity is adequate to serve the needs of the 1 500 inhabitants of the village. The treated wastewater is discharged to one of the arms of the Tisza River.

Operation and Maintenance

The operation of this technology requires one mechanical engineer. Additional staff may be required depending on the size of the plant needed to serve a particular community. This technology uses standard wastewater treatment techniques and readily available materials.

Level of Involvement

This technology is implemented at the local community level.

Costs

The cost of a typical activated sludge treatment plant is about $400 000.

Effectiveness of the Technology

This technology can achieve an effluent with a BOD₅ concentration of 30 mg O₂/dm³, an organic matter content of <50 mg/dm³, a total nitrogen concentration of <30 mg N/dm³, and a total phosphorus concentration of <5 mg P/dm³.

Suitability

This technology provides treatment of domestic wastewater which is transported to the treatment plant via a piped drainage system or discharged directly into the plant by vacuum-storage trucks. It is ideal for small settlements, institutions (e.g., hospitals, schools, etc.), and holidays resorts, where the capacity of the plant is between 20 and 125 m³/day.

Advantages

This biological reactor is suitable for quantity and quality equalization of domestic wastewater. Detention time is optimised the reactor for the highest treatment efficiency. The secondary settling tank is loaded at a constant rate, and achieves a treated wastewater that meets Hungarian water quality standards. It is easy to control because the equipment and pipelines are situated on and above ground level. The air-blowers, which are built with a safety operating mechanism, require less operation and maintenance than other technologies. The need for sludge treatment is minimal in this technological process.

Disadvantages

If the plant is not covered, it is sensitive to cold weather. Pipelines may freeze in very cold weather.

Cultural Acceptability

This technology is an accepted and efficient wastewater treatment technology.

Further Development of the Technology

The technology is fully developed.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

BIO-CLEAR® Wastewater Treatment System Another example of activated sludge treatment technology used in Hungary is the BIO-CLEAR® wastewater treatment system. These systems ensure highly efficient biological treatment of wastewater flows in the 50 - 1 000 m³/d range. Depending on the treatment requirements, this treatment system can be a one- or two-staged biological treatment. The one-stage biological treatment method consists of simultaneous oxic (substrate removal, nitrification) and anoxic (denitrification, reduction) zones, while the two-stage treatment includes further mechanical primary sedimentation and high load trickling filtration. The BIO-CLEAR® technology has four modifications: BC-1 is for domestic wastewater treatment (350-450 g/m³ BOD5) with denitrification and aerobic sludge treatment; BC-2 is for domestic wastewater treatment with denitrification and phosphorus removal; BC-3 is for wastewater with an high organic pollutant load (e.g., agricultural and industrial wastewaters with up to 1 500 g/m³ BOD5) and includes pretreatment; and, BC-4 is for the same high load wastewater with an higher treatment efficiency.

3.11 Microbiological wastewater treatment

Technical Description

Microbiological treatment of highly organic wastewaters is rather simple but expensive technology that is mainly used to treat septic tanks, grease traps, industrial settlers, liquid waste disposal ponds, and highly polluted waterbodies, etc., by enhancing naturally-occurring bacterial populations. One example of this type of treatment is the BIO 2000® system, which uses a Lactobacillus inoculum (250 000 cells/ml) to decompose organic wastes. Under organic carbon-rich conditions, the initial inoculum of bacteria doubles approximately every 20 minutes and maintains this growth rate as long as the amount of carbon is sufficient for bacterial growth. Excess bacteria generated during this process can be used as fertilizers, while the treated effluent can be reused for most purposes. Table 4 shows typical levels of microbial uptake of a range of water quality indicators that can be achieved using this technology.

TABLE 4. Typical Water Quality Improvement Using Microbiological Treatment.

Parameter	Indicative Reduction Achieved
BOD	70%
COD	75%
Suspended Solids	80%
Nitrate	81%
Phosphate	84%
Sludge layer	50%

Extent of Use

This method has been well tested in Latvia, and has been used in the reconstruction of biological wastewater treatment plants that treat wastewaters from the meat processing industry and wastewater from zoological gardens. Between 1995 and 1997, 4 septic tanks, 2 grease traps, 2 sludge repositories, and 2 greenhouse waste disposal sites were treated using this technology, with excellent results. There are currently a further 10 projects using this technology underway.

Operation and Maintenance

This technology requires a very small staff to implement. The production of the bacterial inoculum, however, requires highly specialised staff and facilities. Nevertheless, such staff and facilities can service numerous treatment facilities.

Level of Involvement

This technology is generally applied by district and local level administrations.

Costs

This technology has a relatively low investment cost (excluding the microbiological laboratory). Commercially available bacterial inocula cost about $200/100 g unit.

Effectiveness of the Technology

This technology can be used to treat approximately 1 400 to 2 000 m² of water surface, or 300 to 500 m³ of manure of liquid wastes. The treatment is normally applied as a single step in surface waters and repeated after 3 to 6 months in the case of wastewater treatment use.

Suitability

This method can be used in wastewater treatment, waste treatment, fatty waste treatment including treatment of wastewater from animal processing activities, and treatment of artificial ponds and polluted surface waters.

Advantages

This technology has little or no energy demand. Excess bacteria produced by this technology may be used as fertilizer.

Disadvantages

The technology is expensive if used on a large scale. Currently, the marketing of this technology is proprietary and under the control of a single (US) company.

Cultural Acceptability

There are no known problems of cultural acceptability associate with this innovative treatment method.

Further Development of the Technology

More investigation of the efficacy of this technology is needed.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

3.12 Packaged wastewater treatment plants

Technical Description

Small sized wastewater treatment plant technologies have been built as compact units to serve the wastewater treatment needs of small settlements. This technology has many modifications which are typically based upon the activated sludge wastewater treatment process described elsewhere in this document.

Wastewater flows, following screening and settling of particulate, enters the tank unit, which includes a biosorber, a clarifier-regenerator, and a sludge mineralizer. In the biosorber, the wastewater is mixed with activated sludge recycled from the regenerator. At this stage, active adsorption of soluble and suspended solids takes place. The activated sludge, then, is settled in the clarifier and directed to the regenerator. In the regenerator, the sorbed and suspended solids oxidation is completed and the activated sludge recovers its original characteristics. Since the introduction of thin-layer modules, the time required for clarification in these packaged plants is reduced and the sludge is thickened better, which consequently allows the system to maintain a large dose of sludge in the regenerator and the sorber. The excess sludge is discharged into the aerobic mineralizer, where it is stabilized and dewatered in filtration bags under air pressure, with no chemical reagents being used. The dewatered sludge is an excellent fertilizer.

Extent of Use

This type of technology is widely-used, with country-specific modifications and special designs to suit local conditions and effluents, in Latvia, Poland, and Hungary. Typical treatment plants range in capacity from 10 to 1 000 m³/day, and serve populations of between 40 and 5 000 individuals. The plants are meant to treat domestic wastewaters and/or industrial wastewaters of similar composition.

Operation and Maintenance

This technology is easy to start and recovers quickly after temporary stoppages. It is also easy to operate, and does not require constant maintenance and full-time maintenance personnel, chemical reagents, or post-treatment disinfection.

Level of Involvement

This technology is implemented at the local administration level, or through some organized scheme of promotion on a local or country level.

Costs

No cost data are available, but costs may be assumed to be similar to those of conventional activated sludge treatment plants of similar capacity.

Effectiveness of the Technology

This technology can produce an effluent with concentrations of 10 mg/l suspended solids, 8 mg/l BOD₅, 4 mg/l ammonium nitrogen, and 1 mg/l phosphate (P₂O₅).

Suitability

Packaged wastewater treatment facilities are designed for use in small districts, single households, and villages.

Advantages

Activated sludge technologies have a proven track record of reliability, with long-term expenditures for operation and maintenance being within 50% to 150% of the norm, and consistent effluent quality (BOD concentrations ranging from 100 mg/l to 500 mg/l). The plants are relatively odour free, and packaged plant, compared to analogous conventional activated sludge plants, and are 2 to 3 times more compact; have internal sludge disinfection, handling and dewatering processes, and lower construction costs (by 1.5 to 2 times) and equipment costs (by 3 to 4 times); and produce excellent fertilizer as a byproduct.

Disadvantages

Activated sludge technologies are sensitive to overloading and contamination, especially by heavy metals. Packaged plants, in particular, in Eastern Europe are susceptible to theft and vandalism. The technology needs skilled consultants to put it into operation.

Cultural Acceptability

This technology is an efficient wastewater treatment technology well accepted by engineers and society.

Further Development of the Technology

The technology is complete in itself.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Street, 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

3.13 Oxidation and stabilization ponds

Technical Description

Many chemical compounds are biodegradable, besides the organic substances which originate from living organisms. Specialised microorganisms (e.g., bacteria and algae) are able to utilize hydrocarbons, mineral oils, phenol, heavy metals, artificial substrates, plastic, etc., as food resources. These biological processes form the basis of most new methods of wastewater treatment. Similarly, these processes often lend themselves to use in a well directed and controlled structure, for example, in activated sludge treatment systems, trickling filters, or stabilization ponds and biomechanical treatment systems.

The main biochemical processes can be separated into four groups: anaerobic, aerobic, facultative, and aerated. The appropriate planning of the pond systems make it possible to treat raw sewage, pretreat raw sewage, and final treat biologically purified sewage. Bacteria eliminate the organic substances present in the wastewater, while algae produce oxygen. Bacteria act in both an aerobic degradation mode, where the energy source is organic carbon and the oxidized products originate from CO₂, SO₄, and PO₄; and an anaerobic-reduction mode. These latter processes include facultative processes wherein heterotrophic bacteria produce fatty acids, alcohols, and aldehydes from organic substrates; and anaerobic processes wherein methane bacteria transform carbohydrates to methane by fermentation. Likewise, algae are capable of autotrophic and heterotrophic modes of action. The photosynthetic groups are the most important because they produce oxygen for the bacteria and animals. If the water is acidic (an H-donor), then the dominant process is autotrophic photolithotrophy. If there are any organic compounds, then it is heterotrophic photolithotrophy. The main algal genera are Chlamydomonas, Chlorella, Ankistrodesmus, Scenedesmus, Oscillatoria, Anabaena, Phacus, and Euglena. Under suitable conditions, protozoans, rotifers, and nematodes feed on the algae, thereby also playing an important role in the metabolism of the pond.

Use of an oxidation pond system for the final treatment of sewage from oil refineries has been very successful. For example, after a 40 day retention period, the 500 mg/dm³ COD concentration of an oil-sewage water emulsion was reduced to between 150 and 180 mg/dm³. In another case, following the activated sludge treatment, the oily, polluted water was final treated in an aerobic oxidation pond with a 40 day retention time. This resulted in an 80% decline in oil concentration in the effluent.

Similarly, biomechanical combined oxidation system effluent treatment technologies have been developed using similar technology to purify domestic sewage from communities with a population of between 2 000 and 200 000 individuals. This technology is also particularly suitable for the treatment of strong organic wastes. The technology is similar to that used in stabilization ponds, because it is based on the natural biodegradation processes. Purification takes place in a series of treatment units. After primary settlement, the sewage flows into the first treatment unit, which is operated as a pre-treatment section and is designed to achieve a 70% to 80% BOD removal efficiency. The remaining units operate as secondary treatment systems wherein oxygen is produced by photosynthesis. This treatment efficiency can be increased by the simple application of sand filtration as a tertiary treatment stage. In this type of biomechanical system, the treatment units are arranged as rings in which oxygen is produced by photosynthetic symbiotic bacteria and algae in the secondary treatment unit which surrounds the circular pretreatment unit. Treatment efficiency is increased by recirculating the liquid between the various treatment units, generally using an automated pump system. The oxygen produced by photosynthesis is supplemented by means of a floating mechanical aerator placed in the first stage of treatment. This aerator is operated intermittently by automatic control depending on oxygen concentrations within the units.

The concentration of active biomass contained in the biomechanical units is considerably less than that required for conventional activated sludge or oxidation ditch treatment, and the aeration system has a specific power demand of approximately one tenth that used in a conventional plant. A major advantage of this system is the fact that no surplus secondary sludge is produced and; therefore, no settlement tank, sludge treatment system, or sludge return facilities are required in the secondary treatment stages.

Extent of Use

All the known biological technologies used in Hungary are used for the treatment of different sewage waters. The first stabilization ponds in Hungary were built about 60 years ago. Since the 1960s, the number of these ponds has increased, largely due to their application for the treatment of wastewater from chemical works. Stabilization ponds are also widely used in Poland. In Latvia, where there are large systems of poldered lands, nutrient-rich and pesticide-contaminated surface waters are drained water to biological stabilization ponds prior to discharge to natural surface waters.

Operation and Maintenance

Operational and running costs are 40% to 70% less than those normally associated with single stage, conventional treatment systems. Total power demand also is reduced by 50% in comparison with conventional activated sludge systems. The total treatment efficiency of the system, however, is approximately 90% of the conventional plants. Maintenance is very simple and includes the removal of excessive aquatic vegetation. This system has been tested over many years and is considered to be a proven technology in the region.

Level of Involvement

Oxidation, stabilization and biomechanical treatment technologies are generally implemented at the local administration, corporate, and household levels.

Oxidation Ditch A variation on the oxidation, stabilization, and biomechanical wastewater treatment pond technology is the oxidation ditch, a closed loop around which the mixed wastewater is circulated by horizontally mounted aeration rotors, whose number depends on the applied load and the degree of purification required. The circulation channel generally has a trapezoidal cross section width of 0.5 m to 3.0 m and a depth of 0.8 m to 1.3 m. The ditch can be artificially lined if the soil conditions warrant. Unlike the pond systems, the oxidation ditch usually has a separate final settlement tank. Different aeration systems can be placed at various point within the ditch to achieve the same effect as multiple pond basins (i.e., by using a surface aerator with an efficiency of 1.2 to 2.4 kg O2/kWh, a fine air diffusor with an efficiency of 1.5 to 3.6 kg O2/kWh, or a coarse air diffusor with an efficiency of 0.9 to 1.2 kg O2/kWh). To avoid low efficiencies as a result of high dissolved oxygen concentrations, oxygen meters should be placed to monitor dissolved oxygen concentrations and control the aerators. After bar screening, wastewater enters the aeration ditch where it is mixed thoroughly with air. Aerobic bacteria present in this chamber use the oxygen to convert the organic wastes into a more reduced form. After aeration, the liquid flows into the settling chamber where the suspended particles and activated sludge are separated from the effluent. The loading rate of the system is low; the hydraulic retention tune is high. Oxidation ditches, with a treatment capacity of 40 to 10 000 m³/day, are a popular treatment system in communities of about 10 000 persons in Hungary.

Costs

Costs depend on the scale of a project. For agricultural stabilization ponds, the ponds are sized at approximately 3 to 5 m³/ha of agricultural land served, and building costs are at the level of $10 to $20/m³ of pond volume.

Effectiveness of the Technology

The efficiency of operation of stabilization ponds depends mainly on the environmental conditions (light, temperature, etc.), and the quantity and quality of the sewage water. Sewage stabilization ponds have a great economic advantage compared to other treatment techniques, but the efficiency of treatment is lower. Biomechanical systems with primary settlement can achieve a 70% to 80% BOD removal efficiency. With secondary treatment, these units can achieve approximately 90% BOD removal efficiency. This efficiency, however, depends mainly on environmental conditions and can vary as the quantity and quality of the sewage varies.

Suitability

These technologies are suitable for use in the treatment of domestic and industrial sewage. In many cases, two or more biological methods are used in series. The number of treatment units required depends on the nature of the effluent being treated, but the construction of additional units is simple and economical. The system is particularly suited for the treatment of strongly organic wastes, especially where there are wide variations in the volumetric and BOD loadings. The system has an inherent buffering characteristic and is particularly suitable for use in situations were shock loading and pH variations are expected. It is consequently resistant to "bulking", which is often a major problem with activated sludge systems.

Advantages

This is a cost-effective technology.

Disadvantages

The disadvantage of the biomechanical systems is their dependence on climate and weather conditions. At low temperatures, as in winter, the natural biodegradation processes are very slow and the rate of algae growth is limited. In such circumstances, the efficiency of the treatment decreases. In summer, though, the systems respond with high rates of algal growth, which can result in a measurable COD concentration in the outflow. Oxidation, stabilization and biomechanical pond technologies are land-intensive technologies.

Cultural Acceptability

This technology is an efficient wastewater treatment technology, well accepted by engineers and society.

Further Development of the Technology

The technology is complete in itself.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

3.14 Water recycling in the galvanic metals industry

Technical Description

Plating requires a large amount of water, much of which can be provided through the reuse of wastewater. With use of new techniques during the plating stage, combined with recycling of process waters, it has been possible to reduce water consumption by up to 90% of the original volume of water used. The general method comprises various possible technical solutions which can be applied within the galvanic metals industry to specific processes. The more efficient use of water by recycling is important not only because of the reduction in the volume of wastewater discharged, but also because of the potential for industrial effluents to lower the treatment efficiency of municipal wastewater treatment processes. For example, one of Hungary's largest metal plating factories is located in Miskolc in the northern part of the country. This plant has sophisticated wastewater treatment facilities which provide the level of treatment necessary for discharge into a natural river. Notwithstanding, one part of this system comprises a recycling system which is able to recycle washing water. The recycled water is treated in an ion-exchange system at a rate of 8 to 12 m³/hour. The system has acid and base collecting reservoirs as well as neutralization basins, and the polluted wastewater from each technological process is segregated depending on its metal content. NaOH, HCl, NaSO₃ and NaOCl are used to neutralize these wastes before filtration and pH adjustment prior to reuse. The water circuit of the galvanic plant is completely closed.

This same plant also uses a batch-type, multiple counter-current rinse system. In the first tank, the water is static and does not flow out. This tank is used for the first, "rough" cleansing of the "work pieces" or items being manufactured. During this rinsing phase, the metal content in the water increases by up to 10% to 20% over that of the working solution. Once this concentration threshold is reached, the water is either recycled back into the processing solution used during the plating process (to supplement losses due to evaporation and spillage when the plated metals are removed from the tank). In the counter-current tanks, the work pieces are submerged in the water and moved against the water flow. In this way, the work pieces come into contact first with the most polluted water and, finally, is removed from the cleanest water. This is achieved, in practice, through the use of a cascade system. The basin is separated into compartments, with the cleaner water placed at the highest levels so it flows down into the progressively more polluted compartments. The disadvantage of this type of technology, however, is that the concentrations of the dissolved substances can become very high, which can make the treatment of wastewater difficult. If the main dissolved substances are sulphate-and phosphate-ions, use of CaCO₃ for neutralization instead of NaOH can reduce the dissolved solids content; in other cases, the best solution is the use of raw water with a low salt concentration.

Boiler water condensate is also recycled after it is mixed with desalinated water. It is reused in the gas boilers as supply water. Because the condensate must contain minimal hardness and few suspended solids, the recycled water is routed through an anthracite filter at 900°C and softened with ion-exchange resin. The resin itself may be regenerated with a 100 g/l concentration NaCl.

Extent of Use

These technologies are used in recently modernized plating and metallurgical factories. Examples of closed water cycles in the plating industry may be found in Hungary, Poland, and Ukraine.

Operation and Maintenance

Once installed, the recycling system can be controlled automatically or manually. However, a specially designed installation is required and technically trained staff are needed to operate the system.

Level of Involvement

This technology is implemented at the company level. Financial assistance from industry or governmental organizations is a important factor in offsetting the relatively high capital costs of installing recycling technologies.

Costs

The investment and maintenance costs are difficult to identify because the original plant has been rebuilt in several phases over many years. Different treatment technologies are used for various plating processes according to the customers' orders.

Effectiveness of the Technology

This is an highly effective group of technologies. It is possible to save up to 90% of the original volume of water used by plating industries.

Suitability

These technologies are best suited for use in the plating and metallurgical industries.

Advantages

The primary advantages of these technologies are the overall water savings, enhanced environmental compliance, and reduced usage of chemical agents.

Disadvantages

The disadvantage of these types of water saving technologies is the high concentration of dissolved substances in the wastewater, which makes wastewater treatment difficult. However, these difficulties can be minimized by other process modifications.

Cultural Acceptability

This technology is culturally acceptable.

Further Development of the Technology

Future developments should provide for less expensive means of materials processing.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

3.15 Recycling of wastewater in the transportation industry

Technical Description

Recycling of wash water in the transportation industry can benefit not only transportation companies but also individual owners of motor vehicles. An example of the former is the use of recycled wash water by BORSOD VOL, one of the biggest bus transport companies operating in Borsod County, Hungary. In 1985, they installed a new, water-saving wastewater treatment facility for wastewaters resulting from washing at the central service plant. An example of the latter is the system for the treatment of oily wastewater from car washes introduced in Hungary during 1991.

The commercial transportation system uses detergent-free, high pressure, hot water to remove dirt and grime from the car bodies and engines of the buses. The resulting wastewater is mechanically treated in an OSZTVB-15 15 m³ capacity filter system, the main parts of which are dual filters, an aerator, and an Al₂(SO₄)₃ and NaOCl dosing assembly. The filters consist of two layers: 1 mm to 2 mm diameter sand, and AQUAPOUR-D® activated carbon. For disinfection, a 1 to 3 mg/l NaOCl solution is used. The filters are backwashed with recycled water every 3 to 4 days. The polluted backwash water is returned to the treatment plant. Oily rainwater from the yard is also directed into the treatment plant.

The private system also uses fine sand filtration after pretreatment of the wastewater to remove grit, sand and oil. After this pretreatment, about 15% to 20% of the wastewater is discharged into a conventional sewerage system. This discharge prevents the accumulation of TDS and organic substances in the remaining water which is recycled for use in the carwash. This discharged water meets the water quality requirements for all categories. The remaining water that is to be recycled is subjected to ozonation (see the description of this technology elsewhere in this document) to prevent anaerobic digestion of organic materials which produces foul odours. After ozonation, the remaining, pretreated water is conveyed through a fine sand filter by pump. Once filtered, the water is resupplied to the carwash by means of a rubber membrane hydrophore at a pressure of between 2 and 8 bar.

Extent of Use

A few examples of similar technologies in Poland, Hungary and Latvia. Further, the private car wash recycling technology is being implemented in new petrol stations being built in Poland, Hungary, and Latvia, as well as those being renovated to meet new national environmental standards in those countries. While it is not unusual for modern petrol stations to include a car wash facility, high water prices create an urgent need for economical water use, which addressed through wash water recycling.

Operation and Maintenance

There is no need for highly trained personnel for operation. The systems are fully automated; only one-man supervision is required.

Level of Involvement

These technologies are usually implemented at the company level.

Costs

For the commercial vehicle washing recycling facility, the initial investment costs are about $80 000, with a further investment of about $1 600 likely to be required for reconstruction after about 10 years of operation. The initial investment in the private car wash recycling facility is somewhat less at about $20 000. Maintenance costs are about $4 000/year. The estimated period for recovery of this investment is about 1.3 years based upon typical usage within the region.

Effectiveness of the Technology

The achieved efficiency of water recycling is 80%.

Suitability

Method suitable for use by public transportation firms and petrol stations with car washing facilities.

Advantages

These technologies have an high treatment efficiency, easy maintenance, and simplicity of operation. The washing bays have a reliable construction, and, in the case of the public washing station, detergent-free operation.

Disadvantages

Disadvantages of these technologies include the need for sludge treatment, especially in the case of the public system which does not discharge contaminated wastewaters to the public sewer system, and the danger of freezing during winter.

Cultural Acceptability

There are no barriers to cultural acceptance of these technologies.

Further Development of the Technology

The technologies are adequate to meet required standards for water savings and effluent quality.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

3.16 Recycling of water in the power generation industry

Technical Description

The technology comprises a number of water savings opportunities which can be realized through the application of alternative technical approaches to the use of water in the power generation industry. For example, the Riga, Latvia, Thermal Power Plant Number l uses a large volume of surface water for cooling, and, after passing this freshwater once through the cooling process, discharges this entire volume of chemically and thermally polluted water to Lake Kišezers, situated in the City of Riga. Based upon the reconstruction experience obtained at the Riga Thermal Power Plant Number 2, it is proposed that this once through system be replaced with a treatment and recycling system that should consume significantly less water. After cooling, the cooling water used at the Number 2 Plant is biologically treated in ponds and recycled. This system is largely closed, with only small volumes of supplemental water being withdrawn from Lake Kišezers.

Extent of Use

Similar projects are under construction, or have been completed, in a few thermoelectric power plants in Poland, Ukraine, and Hungary.

Operation and Maintenance

Use of the treatment and recycling technology is fully compatible with standard operation and maintenance procedures in thermoelectric power plants. However, the recycling system does require some additional maintenance in order to recirculate the treated cooling water and to operate the biological treatment ponds.

Level of Involvement

This technology is generally implemented at the company level.

Costs

Costs are difficult to identify, and depend on scale of the project.

Effectiveness of the Technology

At Riga, it is anticipated that the introduction of recycling of cooling water will reduce water consumption at the power plant by 9.5 times. Recycling the treated cooling water for other purposes at the plant should increase reuse by up to 25 times. Specifically, the use of water for industrial purposes prior to reconstruction of the plant consumed 30 x 10⁶m³/year. This volume is expected to be reduced to 3.1 x 10⁶m³/year, or about 10% of the previously consumed volume. Use of recycled water is expected to increase from about 43 x 10⁶m³/year to almost 71 x 10⁶m³/year, or a 1 650% increase.

Suitability

This reuse technology is suitable for use at thermoelectric power plants.

Advantages

All of the cooling water, process water, and wash water used in the power plant is treated and reused. The greatest benefit of this technology is the prevention of thermal pollution in the lake.

Disadvantages

No disadvantages have been identified. Some modification of the wastewater collection and circulation systems must be undertaken, which has a cost impact.

Cultural Acceptability

This technology is accepted as a profitable and efficient environmental technology.

Further Development of the Technology

The technologies used in the Riga Project were designed by the Latvian State Enterprise "Siltumprojekts", which is main design authority for power production and supply in Latvia and the Baltic States.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Str., 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

3.17 Irrigation with diluted liquid manure

Technical Description

The basic principle of this technology is water recycling within a partially closed agricultural system. The liquid manure is diluted with surface water (in part, used to wash out the barnyard), use to irrigate the agricultural areas, and collected as a return flow from the fields for secondary use. Pig and cattle sheds can be designed and built to collect liquid and solid manure to permit these wastes to be flushed to a collection point where they can be used for irrigating grasslands, fodder fields, and vegetable growing areas. The volume of wastewater that can be collected from a 30 000 pig shed amounts to 120 000 m³/year. While it is technically feasible to reuse this entire volume, the reuse of water may be limited by the allowable fertilization rates for the lands being irrigated. For example, one particular pig operation is limited in its reuse by the amount of nitrogen in the wastewater (the allowable fertilization dose in this case is 300 kg N/ha).

The irrigation system at Limanti, Latvia, is an example of this type of agricultural reuse system. The system employs two stationary pumping stations, one of which is for pumping the liquid manure and the other is for pumping freshwater from the Daugava River. Smaller pumping stations are used for recycling the return flows to the manure collection reservoir. This collection reservoir is located within the drainage system of the irrigated area. All surface flows and drainage waters are gathered in this reservoir. The main piping conduits are 500 mm diameter steel pipes which deliver the water and manure to asbestoconcrete pipes ranging in diameter from 300 mm to 500 mm. The liquid manure is screened before being irrigated, and, should additional storage be required, temporary reservoirs for storing the diluted liquid manure within the fields may be constructed with plastic screens.

Extent of Use

This technology has been well used in Latvia since the early 1980s. More than 10 large pig farms, housing more than 10 000 pigs each, and almost 100 large cattle farms, with more than 400 cows each, have constructed this type of reuse system. This method is used in Latvia, Lithuania, and Russia.

Operation and Maintenance

Good meteorological information is required to prevent water-logging of the fields. Likewise, skilled agronomists are needed to determine appropriate manure application rates to provide adequate fertilization of crops and to minimize the potential for groundwater contamination by nitrates, etc. Skilled mechanics (two for running the pumping stations and 8 for operating the irrigation equipment, in two shifts) are also very important for the successful operation and maintenance of this type of system.

Level of Involvement

While this technology is generally implemented at the local farm level, monitoring and control by environmental authorities of groundwater, wells, soils, and surface waters, and by health authorities, to assure the quality of the produce, is often necessary.

Costs

The construction cost of this type of reuse system is about $10 000/ha, and the anticipated payback period is 6 to 8 years. Recurring irrigation costs are estimated to be about $ 1 000/year. The net improvement in crop yields through the use of liquid manure is approximately 200 centners of fodder per hectare. The water saving and environmental issues are additional benefits derived from the use of this technology, but are difficult to estimate.

Effectiveness of the Technology

Use of this technology has resulted in an harvest of grass of up to 600 centners/ha. The efficiency of the system is high, and additional environmental benefits and water savings occur. Agricultural production is increased by approximately 2 times, and the use of mineral fertilizers is decreased by more than 2 times. Further the total volume of freshwater used in irrigation is decreased from 3 m³/ha to a total of 2 m³/ha, 1.5 m³ of which is freshwater. This results in a savings of 50% in freshwater usage.

Suitability

This technology is suitable for use in areas suited for irrigated agriculture, and is especially suitable for use on large farms.

Advantages

Use of this technology results in significant water savings and improved environmental protection.

Disadvantages

Irrigation equipment requires an high degree of maintenance. Parts for older-style irrigation systems may not be readily available, and it may be necessary to replace older equipment with more modern (and readily available) machinery.

Cultural Acceptability

This technology is related to traditional methods of fodder production and is well-accepted.

Further Development of the Technology

A better understanding of the economic value of the environmental protection benefits is needed. Also, monitoring should be conducted to determine the long term environmental issues relating to using this type of technology.

Information Sources

Rolands Bebris, Ministry of Environmental Protection and Regional Development, 25 Peldu Street, 1494 Riga, Latvia, Tel. (371-7) 227145, fax: (371-7) 820442, e-mail: BEBRI@VARAM.GOV.LV.

Anna Egle, V/U "Meliorprojects", 11 Novembra Bulvaris 31, LV-1494 Riga, Latvia, Tel. (371-7) 228734.

3.18 Reuse of cooling water for fish farming

Technical Description

This technology is based upon the use in fish hatchery and farming operations thermally-polluted cooling water discharged from an electric power plant. The farming operation in which this technology is used deals primarily with European fish, but the technology is particularly suited to raising Asian fish as the farm is supplied with warm water.

In Hungary, this technology is used at TEHAG Ltd. The water in this hatchery's ponds does not cool to below 20°C during May and June, as other Hungarian waters are frequently wont to do, and hence fishes which are highly sensitive to cool (16° to 18°C) water mortality during the first weeks of their lives can be reared safely. This facility rears about 300 to 400 million larvae annually in a propagating house with a floor area of 1 500 m². The farm also has 131 ha of fish ponds, with more than 80 compartments ranging in area from 100 000 to 300 000 m². Because fish farm production is very intensive, the rearing ponds are treated annually with several hundred kilograms of inorganic fertilizer (N and P) and 3 to 5 Mg of organic fertilizer. Oxygen is supplied by aeration. All stages of work are highly mechanized. Production is facilitated by modern, automated, heated hatchery and nursing halls, fry storage tanks, self feeders, fish sorting conveyors, and vehicles equipped with an oxygen supply for transporting fish. A unique characteristic of this type of technology is the simultaneous propagation of breeding fishes having different spawning times and temperature requirements. The annual water demand of 1.6 million m³ is supplied through an gravity-fed, underground pipeline system which carries cooling water effluent from a power plant on the Danube River. The temperature of this water is 10° to 12°C higher than that of the river water, which not only makes warmwater fish propagation possible, but also prolongs the propagation season for coldwater fishes. After use in the fish farm, the water, now cooled to ambient temperatures, is discharged through Benta Creek into the Danube without causing any heat pollution. Fish yields in the farm are among the highest in Hungary with an average of 1.8 to 2.6 Mg/ha, ranging upwards to 3.5 to 4.5 Mg/ha in some ponds.

Extent of Use

This reuse technology is only known to be employed at one site in Hungary.

Operation and Maintenance

Operation and Maintenance requirements of this technology are the same as employed at conventional fish farming operations, and require the same level of water quantity and quality control measures.

Level of Involvement

This technology was implemented at the company and local administration level, with financial backup and support from relevant governmental organizations.

Costs

The farm was constructed between 1970 and 1974 by the Food and Agriculture Organization of the United Nations (FAO) and the Hungarian government at a cost of $2 million. Maintenance costs are difficult to identify. Beside fish breeding, the farm doubles as a development and training centre, and the costs of lecture rooms and guest houses for the purpose of training persons in the operation of fish farming enterprises mask the net cost of the reuse technology.

Effectiveness of the Technology

The technology is fully effective in preventing the thermal pollution of natural water ecosystems and the resultant water quality deterioration.

Suitability

This technology is suitable for use in localities with appropriate soil conditions and relief, situated near power plants.

Advantages

This technology has the advantage of preventing the thermal pollution of natural waters while producing marketable goods.

Disadvantages

This is a land intensive technology.

Cultural Acceptability

This technology is a well-accepted, efficient wastewater treatment technology.

Further Development of the Technology

The technology is complete in itself.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

3.19 Reuse of wastewater for irrigation of a snail farm

Technical Description

The Mantar Kft. edible snail processing factory was established in Nyiregyhaza, Hungary, in 1993. Processing consumed 110 m³/day of drinking water during the processing season which lasts for four months. The amount of resulting wastewater is about 60 m³/day. Originally, the treatment of this wastewater was difficult because of the high chemical oxygen demand of the water (almost 3 000 mg/l) and the high concentration of sodium salts added as cleaning and whitening agents during the washing of the snail shells. While the amount of sodium salts Used in this process could be reduced to about 60 kg/day, no other chemicals suitable for cleaning and whitening the shells of the snails were readily available. Mechanical and chemical pre-treatment of the sewage with ferric chlorite and lime cream, however, was able to reduce the COD by up to 70%. Notwithstanding, final disposal of the treated wastewater was problematical due to the lack of a suitable receiving surface waterbody.

In order to obviate the problem of sewage disposal, the factory decided to establish a snail stock-farm, where the treated sewage could be reused as the water supply to irrigate the feeding plants. To retain the irrigated effluent within the snail biotope, a ridged poplar tree filtering system has been planted, and fencing installed on the ridges to prevent the migration of the snails and any direct contact with the polluted water. Until the cultivated snail's breeding plants reach an optimum size, the farm is irrigated with clean water to maintain a moist environment.

Extent of Use

This technology is known to be used at only one site in Hungary.

Operation and Maintenance

The operation and maintenance of this technology includes repairs and control similar to that traditionally used in snail farming and processing schemes.

Level of Involvement

This technology is implemented at the company level.

Costs

The capital cost of investment in the treatment facility and additional improvements was $76 800. The cost of the snail breeding farm and required equipment is estimated to be $48 000.

Effectiveness of the Technology

This technology is fully effective in utilizing food processing wastewater from an existing factory for production purposes.

Suitability

This reuse technology is suitable for use in similar situations where food processing factories backward integrate into food stuff production, and where favourable climatic conditions exist (e.g., light winters).

Advantages

The utilization of the mechanically and chemically- pretreated sewage is very economical, and serves as a means of conserving the irrigation water supply.

Disadvantages

No disadvantages have been identified.

Cultural Acceptability

This technology is an accepted and efficient wastewater treatment technology.

Further Development of the Technology

The technology is complete in itself.

Information Sources

PetKovac and Dr Korna H. Kocsis, FelsTisza - Vid Kezetvlmi Fels 4400 Nyiregyh, Szenyi u.19, Hungary, Tel. (36-42) 310 155, fax: (36-42) 310 713.

4.1 Environmental labelling of water-saving products

Technical Description

The environmental label, or eco-label, is an environment-related identification for a product. A product bearing this type pf label has a positive identification, which, currently, is adopted by a manufacturer on a voluntary basis and which attests to the willingness of the manufacturer to comply with a series of environment-friendly guidelines and requirements. The environmental label is a market-oriented, so-called "soft policy instrument" that relies on the information and motivation, conviction and environment-conscious thinking and actions of manufacturers and consumers. Use of the label fits into the competitive marketing strategy of the manufacturer and provides an incentive to the consumer to purchase products with the best possible, environment-related properties. (A further part of this effort is to encourage the development of positive environmental properties by the manufacturer, both in terms of production and packaging.) Eco-labelling has become a widely recognized aspect of product quality. The award of the label to individual products is based on the definition of relevant product groups and related environmental criteria. A very important element in the promotion of environmental labelling is the creation of environmental awareness among the general public. Consumers must be willing to make an environment-related choice when shopping and faced with making a selection between two or more products.

One example of eco-labelling is the environmental label system implemented in the Republic of Croatia. The decision to award the Environmental Label was made by the Ministry of Civil Engineering and Environmental Protection in February 1993, by adopting the Rules on Awarding the Environmental Label. The label consists of a circle containing a stylized sketch of a bird and a fish with the inscription - "Environmentally Friendly" - in the upper part of the label and a description of the reason for the award in the lower part. In order to obtain the Environmental Label, the product has to meet specific requirements defined by criteria established for its award in various product groups. These requirements are established by competent expert institutions. The assessment of product, made by jury, takes into the consideration all environment-related aspects of the production and sale of the product, including cost-efficient use of raw materials, energy, and low waste-generating technologies. When evaluating products, all phases in the life cycle of the product (i.e., the period that includes raw materials acquisition, manufacture, packaging, sales, use and disposal) are taken into account. The duration of the award procedure is between 2 and 3 months per product, depending on a number of factors such as the degree to which the product life cycle is documented. The award is valid only for a specific period of time.

Extent of Use

The Extent of Use of official environmental labelling systems is still limited in the region, although national ecolabelling schemes exist in Croatia and Czech Republic. This method is more fully developed in the countries of the European Union.

Operation and Maintenance

This method is based on the free-market mechanism, wherein consumers use their buying power to strengthen the market for goods which do the least possible harm to the environment. In this case, the ecolabel can be used to promote the adoption of water-saving processes.

Level of Involvement

This technology is best implemented at the governmental level, although producer and/or consumer organizations can also adopt and promote eco-labelling schemes.

Costs

From the point of view of the decision-maker, this technology is a "non-investment". The system is self-financed, with each producer interested in obtaining the label having to pay a fixed sum.

Effectiveness of the Technology

This is a very effective method of raising consumer and manufacturer awareness, and promoting environmentally-friendly action. However, experience in the region is currently limited.

Suitability

Environmental labelling is suitable in all countries in the region with a free market economy.

Advantages

Ecolabelling provides direction to manufacturers that encourages manufacturers to account for the environmental impact of their products. In so doing, ecolabelling stimulate demand for water-saving facilities, and raises the awareness of consumers about protecting the environment.

Disadvantages

In many countries, unofficial, private systems of environmental labelling have been developed. However, in such situations, the consumer may feel confused because of variety of labelled goods and labelling systems.

Cultural Acceptability

Nowadays, people in the region are becoming more interested in searching for, and buying, ecolabelled products, the majority of which imported from countries outside of the region. This technology, therefore, is culturally acceptable and popular.

Further Development of the Technology

Further development of ecolabelling systems in the region requires preparation of a uniform series of legally-regulated labelling systems in the countries where conditions exist for doing so. Ecolabelling systems should be supported by social education and advertising, and can be extended to promote water-saving facilities and products, many of which have already obtained an environmental label.

Information Sources

Vesna Montan, Ministry of Civil Engineering and Environment Protection, Avenija Vukovar 78, 41000 Zagreb, Croatia, Tel. (385-41) 536 197, fax: (385-41) 537 203.

Jean-Jacques Lauture, European Commission, rue de la Loi, B-1049 Brussels, Belgium, Tel. (32-2) 96 8096, fax: (32-2) 29 5684.

4.2 Water-saving fixtures

Technical Description

Water-saving measures taken by households and public institutions also contribute to the conservation of freshwater resources. Replacement or modification of existing household taps and water closets can achieve a significant reduction in water consumption without loss of utility. While all taps can be fitted with aerators and low flow spouts, it is the bathroom bathing and sanitary fixtures that generally consume the largest volume of household water. Hence, application of water-savings fixtures in the bathroom can cause significant water-savings.

For example, the rational consumption of water, and reduction in volume of sewage, from toilets can be achieved by installation of a special device to reduce the flushing-water volume or by using toilets having a dual flush mode. Reduction of flushing volume can be accomplished by householder actions ranging from the placement of a brick into a conventional flushing box, to the purchase of a low volume per flush unit, to the use of toilets with a dual system of flushing, which enables the selection of two or more volumes of water according to nature of the excrete to be flushed. Use of this latter type of toilet typically reduces the volume of household sewage by up to 15%. Installation of new equipment in apartment buildings can save approximately 30% of water in used in the component households.

Water-savings can also be achieved by installation of water-saving shower facilities. Technical modifications including decreasing the effluent rate of the water flow through the shower head by reducing the diameter of outlet pipe, providing for the automatic opening and closing of the water flow, stabilizing the water temperature independently from changes in water pressure, and electronically operating the shower facilities to ensure that the water flow will be automatically interrupted if the shower facility is not used.

Elsewhere in the household, water savings may be achieved through the use of similar types of technologies. Some popular fixtures commercially available in the Baltic States include both kitchen and bathroom appliances and fixtures. Typical water consumption rates of these fixtures are given in Table 5.

TABLE 5. Water Consumption Rates of Commercially-available Household Fixtures.

Fixture	Water Consumption Rate
washing table (tap-mixer)	6 l/min
kitchen sink (tap-mixer)	12 l/min
shower (tap-mixer)	12 l/min
bath (tap-mixer)	18 l/min
toilets (per flush)	4 l.

Extent of Use

This technology is beginning to be used in Poland and elsewhere in the region.

Operation and Maintenance

Installation of these fittings may be done by a plumber or, in some cases, by the individual householder. Once installed, maintenance is minimal and does not differ from the daily household cleaning routine normally employed within the home or public building.

Costs

Costs vary depending on the particular fixture, and can range from being equivalent to traditional or conventional fixtures to 2 times higher. Devices to reduce the toilet flushing-water volume in conventional flushing-boxes are very inexpensive.

Effectiveness of the Technology

Depending on the type of fixture, reductions in the volume of household sewage (and, therefore, in water consumed) can range from 5% to 30% in comparison to conventional systems.

Suitability

This technology is suitable for application everywhere.

Advantages

This technology eases the load on both water treatment and distribution systems, and sewage treatment plants, reducing energy consumption for water and wastewater treatment, and often resulting in savings for the individual householders or building operators.

Disadvantages

No disadvantages have been identified.

Cultural Acceptability

This method in acceptable, especially in regions with an existing market for water. Some public information programming may be required to convince householders that the low flow devices can perform as well as the traditional types of fixtures.

Further Development of the Technology

There is a need for corporate support, advertising, promotion, and social education.

Information Sources

Osmulska-MrB. 1995. The Local Systems of Neutralization of Sewage. Institute of Environmental Protection, Warsaw.

4.3 Water meters

Technical Description

During this century, housing in Polish cities and towns was generally provided within apartment buildings, or "blocks", which housed hundreds of inhabitants. Water was supplied to, and charged for within, these "blocks" based upon the numbers of inhabitants. This system did not require the installation of meters, and water-meters were never installed. Each consumer paid for an allocation of water regardless of their real consumption. More recently, however, the transition to a market economy has resulted in water-meters gaining in popularity. Meters enable individual consumers to calculate their costs according to their real rate of consumption, and allow consumers to make choices regarding their water use habits.

Extent of Use

Water-meters are popular in Poland and Latvia. In Ukraine, however, the lack of cheap water-meters is a decisive barrier to implementing a programme of metering.

Level of Involvement

Water meters are generally installed at the individual household or consumer level by water works companies.

Operation and Maintenance

The installation of water-meters may be undertaken by specialist plumbers or, in some cases, by individuals. Generally, if the water-metering system is to be tied to a water billing system, installation of water meters is undertaken by the water utility company in order to ensure standardization of meters and parts, fair measurement of water volume, and, potentially, remote access to water consumption data for billing purposes.

Costs

In Poland and Latvia, costs of metering are typically about $80 per meter. Of this amount, $40 is allocated to the cost of the water-meters, and $40 to the cost of installation.

Effectiveness of the Technology

Existing data show that installation water-meters has a significant impact on water savings within households. Installation of new equipment in apartment buildings can save approximately 30% of the volume of water previously consumed in households. During 1994, the installation of water-meters resulted in a 50% decline in consumption of water in some households in Poland.

Suitability

This method is suitable for use in all countries within the region.

Advantages

This method eases the load on water and sewage treatment plants, reduces energy consumption for water supply and treatment, and can lead to financial relief for consumers who now pay only for the water that they consume, reducing their costs of water supply and sewage treatment.

Disadvantages

The main problem with retro-fitting existing households and buildings is the poor state of the water pipes in the houses - they must often be replaced at the same time, greatly increasing the cost to the consumer.

Cultural Acceptability

This method is culturally acceptable and is becoming very popular.

Further Development of the Technology

It is expected that, during the next few years, water-meters will be installed in each apartment. However, because not all consumers will benefit from the water savings, there is a need for advertising, promotion, and social education. Less expensive water meters are also needed in some parts of the region.

Information Sources

PoWoGaz s.a., ul. K. Janickiego 23/25, 60-542 Poznan, Poland, Tel. (48-61) 47-44-01, fax: (48-61) 411 501.

4.4 TV inspections

Technical Description

Detection of leakages is a serious problem in all countries within the region. As a result of the lack of water meters (see above), detection of leakage before 1990 was mainly by observation, through inspections of manholes and reports of other external indicators. Since 1990, other technologies have been used to identify leakages within water distribution systems. For example, a large scale survey of the state of water mains in Riga, Latvia, was conducted using aerodetection (by aeroplane and helicopter), which sought to estimate areas where leaks occurred by thermal measurements: leakage from water mains tends to elevate ground temperatures in contrast to the temperature of the surroundings. This survey was used in the preparation of General Plan of City Riga during 1990. Subsequently, more detailed inspections of areas with suspected leakage has been carried out using closed circuit television. The success of this method in Riga has resulted in its introduction in the other large cities of Latvia and in many other countries within the region. This system records the technical state of the piping system on video tape, and the technology can be applied not only to surveys of water and sewerage systems, but also to other pipelines (such as oil and gas pipelines), wells, and other similar systems. The results of the survey may also be presented in the form of a computer printout.

Extent of Use

This technology is currently used in Latvia, and is coming into use with water supply companies and service firms in Poland. However, wider use of this technology in Eastern Europe is limited not only by high costs, but also by political difficulties.

Level of Involvement

This technology is typically implemented at the municipal level by specialized service firms.

Operation and Maintenance

This method should be operated by specialist technicians, and requires specialized equipment and installations.

Costs

This technology costs about $5/linear metre of pipeline. The capital cost of the TV equipment, cleaning equipment, and field station is more than $100 000.

Effectiveness of the Technology

This method is effective in aiding the inspection of sewerage and water supply systems.

Suitability

It is expected that this method will become more popular. It is suitable everywhere, and requires little disruption of infrastructure when used to search for leakages in urban supply and distribution networks.

Advantages

The advantages of this technology include its simplicity and efficiency in leakage detection. The system allows a utility company to check the entire length of the pipeline system, not only those portions which are visible from access points or which evidence surface signs of leakage. The method is user-friendly.

Disadvantages

The disadvantages of this technology are its high cost and requirement for an highly skilled operating team.

Cultural Acceptability

This is an acceptable technology.

Further Development of the Technology

There is a need of promotion of this technology as an effective and non-invasive technique for ascertaining the integrity of distribution systems.

Information Sources

The Department of Sewage System, Potlitechnika Swietokrzyska, Kielce, Al. 1000-lecia PP 1, Poland, Tel. (48-41) 24-620, 24-616; fax: (48-41) 43-784, 42-997.

5.1 Environmental education campaign - "Washing May Be Cheaper"

Introduction

Educational programmes and awareness campaigns are needed to persuade people to adapt their behaviour to the water cycle, and to create recognition that water is neither limitless nor free.

The mission of this campaign was to inform people that, just like this bicycle, both of these circles - representing the household budget and environmental protection - may, and should, turn the same way.

Figure

Technical Description

The environmental educational campaign, under the banner "Washing May Be Cheaper", was conducted by the Institute for Ecology of Industrial Areas in Katowice, Poland, between October 1994 and May 1995. The principal goal of the campaign was to stimulate the behaviour of consumers of washing powders so as to bring measurable savings to the consumers and improve the poor state of the environment. One of the premises of this campaign was the fact that more rational use practices by consumers of washing powders were also advantageous for the environment. Specifically, the campaign was based upon several simple principles, including relating the dosage of washing powder to the hardness of water, supplying washing powders in larger boxes, using lower temperatures and special economy programmes during the washing process, and informing consumers of the higher quality of modern washing powders which make possible different washing regimes to those traditionally used in Polish households. The campaign was conducted in several spheres. People were provided with access to clear, comprehensible information and shown how to change their practices in ways that would benefit the consumer economically - stricter dosing of washing powders could provide an additional economic benefit.

In order to rationally proportion washing powder, it is necessary to know the hardness of the water being used. Hard water requires a larger dose of washing powder than soft water. Information about hardness of water was obtained from the water-supply enterprises. The dosage of washing powder was then adapted to the water supply and specific instructions provided on the packaging of the washing powder. Because it is very important to carefully measure the amount of washing powder, a special measuring glass was provided with the powders. One important lesson which was conveyed to consumers was that an overabundance of powder does not improve the result of the wash. Figure 6 shows an example of a typical dosing instruction.

Dosage instructions for 4-5 kg dry laundry

Figure 6. Typical instructional label provided on washing powder packaging.

Water hardness	Recommended dosage in millilitres, medium soiling (no presoaking, no prewashing)
Soft	275
Medium hard	300
Hard	325
One cup = 200 ml = 100 g The glass is in every box with 2.4 kg of washing powder

Extent of Use

This campaign was conducted in those regions of Poland with soft and middle-hard water. These regions included Katowice, Warsaw, and Bielsko-Biala.

Operation and Maintenance

This campaign used most of the available media: print, television, radio, and videotapes, as well as traditional methods:

- television and radio interviews,

- propagation of informational leaflets, which provided short, easy to read and remember information about washing and its influence to the environment, to 0.5 million families,

- education of teachers,

- education of over 10 000 pupils,

- poster campaigns,

- modification of the user instructions provided with one Polish firm's washing machines,

- establishment of a uniform scale of hardness of water in all over the country,

- propagation of 70 000 self-stick labels reminding people about appropriate dosages (according to the instructions on the packaging) of washing powders,

- organization of a competition among young people from the primary schools of two towns of Poland where there is soft and medium hard water, in which the scholars had to demonstrate a knowledge all of these principles, and the winners were awarded financial and material prizes.

Figure

Level of Involvement

This campaign involved all parts and segments of the population.

Costs

The cost of this campaign was about $60 000. The main sponsor was the National Fund of Environmental Protection and Water Protection, together with some Polish enterprises.

Effectiveness of the Technology

This campaign was expected to produce such positive environmental effects as reducing the amount of harmful substances discharged to the sewerage system, especially those associated with the washing process. This would ultimately reduce the occurrence of water pollution, particularly eutrophication, in waterbodies with soft and medium hard waters. A typical example is the protection of Goczalkowice, the principle freshwater reservoir of the Silesian agglomeration. The campaign was also expected to reduce the consumption of energy and water. In addition, one of the effects of this campaign was to increase awareness of environmental matters among the populace. Before the beginning of the campaign, in October, the population of Poland was polled about their awareness of environmental matters connected with washing. People were asked, for instance, if they were conscious of the influence of their washing on the environment, as well as several other questions concerning the hardness of water in their homes and their method of washing (i.e., type of soap used, adherence to the recommended dosage of washing powder, use of the full capacity of the washing machine, use of energy-saving programmes, etc.). When the campaign was over, in May, people were asked the same questions to determine what effects the campaign had. This second poll indicated that about 10% more people were aware that even such a simple practice as washing their clothes at home influences the environment. In addition, the number of persons who knew the hardness of the water in their home increased by approximately 5%.

Advantages

The essential advantage of this campaign is the fact that changing the everyday practices of people can result in a major reduction in their impact on the water environment. Such behavioural modifications do not require major expenditures of money, but, in contrast, can bring some savings for consumers of washing powder.

Disadvantages

No disadvantages were noted.

Further Development of the Technology

This campaign is still being continued by the Regional Centrums of Ecological Education in Katowice and Bielsko-Biala, and by the Society of Towns and Communes of Drainage Basin of Parseta, which has its seat at Bialogard.

There is a need to organize more of these campaigns which promote sustainable living and consciousness of environmental matters. Such campaigns can help to show people how to change their practices to save water. The effectiveness of these efforts can be increased if the knowledge and perceptions of the target groups are drawn upon in developing the campaigns.

Key points to be considered in such public informational campaigns include:

Ö creation of a basic understanding of the water cycle among decision makers,

Ö promotion of awareness of the water cycle among decision makers,

Ö explanation of the need for everyone to protect water from pollution,

Ö provision of educational materials to improve hygiene and sanitation especially in lower-income communities,

Ö improvement of awareness of the values of wetlands, peatlands and other aquatic ecosystems and the ways they can be sustainably used, among communities, government decision makers, schools and colleges, and the media,

Ö initiation of actions to provide decision makers with syntheses of the best available scientific data so that they can understand the interactions among water users.

Information Sources

Ryszard Janikowski, and Beata Michaliszyn, Institute for Ecology of Industrial Areas, ul. Kossutha 6, Katowice, Poland, Tel. (48-3) 1546031, fax: (48-3) 1541717, e-mail: jan@amnesia.ietu.us.edu.pl.

5.2 Biotechnology-based wastewater treatment

Introduction

Ukrainian Academy of Sciences Institute of Colloid and Water Chemistry, in cooperation with a number of organizations, has developed and implemented a flow-through biotechnology for wastewater treatment that uses a sequence of bacteria and hydrobionts (aquatic fauna) to immobilize contaminant loads. These biotechnologies are widely used in wastewater treatment, drinking water pretreatment, and purification of rainfall and surface waters (in lakes, bays, channels, etc.).

Technical Description

While this technology can be specifically adapted for particular groups of pollutants, this case study will examine the biotechnology proposed for use in the treatment of wastewater from a yeast production facility. This technology includes three stages. In the first stage, the effluent is subjected to anaerobic treatment in three consecutive biological reactors (concrete submerged tanks, filled with "Vija" fibre produced from textured nylon with a specially tailored interlacing). The fibres provide a substrate that approximates sone 10 000 to 100 000 m² of surface area/m³ of fibre. The anaerobes that inhabit this surface area can reduce the COD of the influent wastewater by not less than 80% (as COD). In the second stage, the effluent is subjected aerobic treatment in a modified trickling biological filter, wherein the conventional substrate of rocks has been replaced by additional fibre batting. In this chamber, the effluent is denitrified to rid the effluent of excess ammonia. In the third stage, the effluent is subjected to aerobic mineralization using activated sludge. This stage serves as a final polishing stage in the enhanced water purification process. When the contaminated water emerges from this portion of the process, its BOD is reduced from 3 000 mg/l to 6 mg/l.

Extent of Use

Table 6 lists the industrial facilities in which biotechnological systems of wastewater treatment are in operation.

Operation and Maintenance

Operation and maintenance costs incurred using this technology are 3 times less than the costs of wastewater treatment in aerobic activated sludge tanks, and half as many staff are required to operate this type of technology. The types of professional skills, however, are slightly different to those required in conventional wastewater treatment plants as one staff member should be a biologist-ecologist (in addition to an engineering technician and electrician). Because this is a biological rather than a mechanical system, electric power consumption is reduced by a factor of 3 times. Likewise, because of the mix of aquatic organisms used in this treatment process, the amount of activated sludge is reduced by 5 times. The microorganisms used in the process could be selected from local sources.

Level of Involvement

This technology is typically implemented by the private sector, when employed in the factory setting, or by the municipal sector, when used for community wastewater treatment.

TABLE 6. Application of Biotechnology-based Wastewater Treatment Systems in Ukraine.

Facility	Implementation benefits
	Parameter	Before (mg/l)	After (mg/l)
1. "Khimvolokno" Chernigov Production Association	Deep purification of wastewater to remove hexamethyldiamine	2500-4000	5-0
2. Ivano-Frankovsk Fine Organic Synthesis Plant	Microbial water pre-treatment to remove non-ionic detergents	10 000	20
3. "Azot" Dnieprodzerzhinsk Production Association	Wastewater pre-treatment to remove aniline, formaldehyde, and chlorobenzene	1500-3000	2-50
4. Krasnodar, Afipsky, and Novokuibishevsky refineries, and a joint project with the Krasnodar subsidiary of Sirius Company (Russia)	Deep refinery wastewater purification to remove oil	75-100	0.05
5. Orenburg Gas-processing Plant (Tengiz oil and gas deposit)	Gas-processing plant wastewater treatment to remove methanol, diethanolamine, ethyleneglycol	50 000	10
6. Kiev Household Chemicals Production Plant	Detergent production wastewater treatment	500	15
7. Makeevka Coke Chemical Plant	Wastewater treatment to remove phenols and thiocyanates	1 500	50
8. Makeevka City Sewage Treatment Facility	Deep tertiary wastewater treatment: BOD suspended matter	25 30	4 3
9. Bilche-Volitsk, Ugersk, and Dashava Underground Gas Storage Facilities	Wastewater treatment to remove diethyleneglycol and methanol	10 000	0-20
10. "Lakokraska" Production Association (Lida, Belorussia)	Pre-treatment of dye and pigment production wastewater to remove organic solvents, heavy metal ions and sulfates	7 000	100
11. Nikolaev Hydrolysis and Yeast Production Plant	Hydrolysed lime wastewater treatment (COD)	15 000	500
12. Krasnodar Machine-building Plant (Russia)	Electroplating wastewater treatment to remove Cr6+	50	0
13. "Krasnodarnefteorgsintez" Production Association (Russia)	Oil sludge stratification	40%	1%
14. Shishaki Township and Kobelyaki Village (Poltava Oblast)	Household wastewater treatment (BOD)	400	5
15. Kolindayni Village (Ternopol Oblast)	Yeast production wastewater treatment (BOD)	5 000	6
16. Tripolie Industrial Cluster (paper and cardboard production, lysine production, and municipal sewage effluents)	Tertiary wastewater treatment (BOD) suspended matter	25 30	10 8
17. Chernigov Worsted Facility	Wastewater treatment	600	50

Costs

The capital cost of a biotechnology-based treatment facility with a capacity of 1 500 m³/day is about $2 430 000 (or $1.62 per unit of output). Operation and maintenance costs are 3 times less than the cost of water treatment in aerobic sludge tanks. The fibre batting costs $10/kg. Purification facilities generally use between 0.3 and 3 kg of this material/m³ of effluent treated. In most applications, the depreciated cost of wastewater treatment prior to the introduction of biotechnological-based treatment was $376.10 (or $0.25 per unit of output), and, after its implementation, these costs declined to $150.20 (or $0.10 per unit of output). Under ideal conditions, the biotechnological treatment is self-adjusting once it has been launched.

Effectiveness of the Technology

In urban wastewater treatment applications, these biotechnologies produce an effluent which improves on the performance of conventional biological treatment facilities by 50% to 60% overall. Water quality of the purified water leaving the plant is 5 to 10 times better; typical output has a COD of between 15 and 20 mg/dm³, a BOD of between 2 and 3 ma/dm³, and a suspended matter concentration of less than 2 mg/dm³. Power costs are reduced by 3 to 4 times, and surplus sludge quantities are reduced by 5 to 8 times.

Advantages

Under ideal conditions, the treatment facility is self-adjusting, and can be used to purify any wastewater, including almost toxic wastewaters, to required levels of water purity.

Disadvantages

There are no known disadvantages to the use of biotechnology-based wastewater treatment methods.

Further Development of the Technology

This biological technology is based upon universal principles inherent in aquatic ecology. Hence, this type of system can be used for the treatment of both raw water and wastewater from various industrial and municipal sources. The basic principles employed are the principles of spatial succession of different microorganisms and of the nutritional chain of hydrobionts (the food web). The technology is generally reagent-free, but, in the case of the technology being used for water treatment in chemical facilities, reagents might be also used for pretreatment of the wastewater. Reagents may also be used when there might be a shortage of biological growth elements in the water being treated.

In industrial waterworks, this reagent-free, inexpensive, and environmentally-safe treatment method can replace the traditional chemical (biocide) treatment of recycled water needed to reduce biological growth within heat-exchangers. In natural waters, this technology can be used to completely remove up to 100 ml of oil per square meter of water surface daily.

Information Sources

Dr Vladimir A. Demkin, Ministry of Environmental Protection and Nuclear Safety, 5 Khreschatyk St., Kyiv-1, Ukraine, Tel. (380-44) 228 0786, fax: (380-44) 229 8050, e-mail: demkin@mep.freenet.kiev.ua.

5.3 Beaver reintroduction

Introduction

The natural retention of water within the landscape can be beneficial to providing better hydrological conditions in an area. Besides artificial impoundments, it is possible to enhance water retention by introducing beavers to appropriate areas. Beaver (the Euro-Asiatic Castor fiber and introduced North American Castor canadensis) are aquatic rodents of the family Castoridae (order Rodentia), and are well known for their dam-building activities (Figure 7).

Figure 7. The beaver and its lodge, which is generally built transverse to a stream course forming an impoundment.

Beavers are thickset animals with small, rounded ears, short legs, and large, webbed hind feet. They may grow to about 1.3 m long, including their flat, scaly, 0.3 m tail, and may weigh more than 27 kilograms. Beavers have a preference for streams and small rivers but also live around the margins of forest-edged lakes. Their dams of sticks, stones, and mud may last for years, impounding pools that sometimes cover many acres, which, as with all lakes, eventually fill in with silt to form meadows. Saplings and even large trees are felled by gnawing, cut into portable lengths, and dragged or floated through beaver-made canals to the pond. Beavers live in colonies, one or more family groups to a lodge. A family consists of a mated pair and two sets of offspring. The food of the beaver usually consists of the tender bark and buds of trees. The beaver is a protected species in Poland.

Technical Description

The method of augmenting water resources through beaver reintroduction is based on ecological engineering principles. In this method, a knowledge of local physiographic conditions and beaver species ecology are used to identify suitable sites to which beaver families may be transferred from overpopulated areas. The choice of the reintroduction site is a crucial stage in this process. Some site investigation and research into local development scenarios should be conducted to avoid those areas which are extensively used for agriculture and forestry. This avoids conflict between the beavers and neighbouring humans. These site investigations should also take into account the fact that should, population growth occur among the introduced family in a few years, young beaver might migrate to another nearby locality. Migration generally occurs along main rivers and their tributaries. Migrating animals can settle anywhere regardless of potentially competing human interests; in such cases, the beavers activities may lead to damages such as flooding of agricultural lands. Beavers can also be a threat to some cultivars, such as beets, which are a favourite food.

Ponding behind beaver dams modifies the hydrological regime in the surrounding area. The scale of change in the water regime depends on the prevailing hydrological and geological conditions. Because beavers also make vertical wells (up to 2 m in depth) to access their lodges, water circulation into and through soil layers may be enhanced. One beaver family can create a pond with a surface area of between 100 and 5 000 m². In one reported case, a beaver pond covered an area of 200 ha and impounded about 1 000 000 m³ of stored water.

Extent of Use

In Poland, the introduction of beavers is carried out by the University of Poznan and the Ministry of Environmental Protection Natural Resources and Forestry as part of a national programme of beaver protection. A few other universities in Poland also have field stations which are involved in beaver research and which offer beaver-introduction expertise. The known beaver population in Poland is about 12 000 animals. However, these animals are not equally distributed throughout the country. After World War II, beaver populations were sustained only in a few natural stands in the northeastern part of Poland, and it was due solely to strict protection measures that this species was saved from extinction. This programme, which comprised three voivodships over a 40 year period, allowed the beaver population to achieve a size which now exceeds the ecological capacity of the area, allowing the surplus beaver population to be transferred to other voivodships. In 1995, about 120 beavers (or 30 beaver families) were relocated to new areas. In this process of reintroduction, the voivodship administration takes part in covering the direct costs of reintroduction, in preparing feasibility studies, and in protecting the beavers. Since the beginning of this relocation programme in 1973, 1 800 beavers (400 families) have been relocated to the Oder River basin, and, in the highly industrialized region of the Katowice voivodship, 18 beavers have been introduced in various places.

Implementation of this technology needs the acceptance by the local community of the animals as a positive natural element. Many people in rural areas still view the beaver as a nuisance, and several have been killed (e.g., at TarnGdansk Voivodship).

Operation and Maintenance

Operation and maintenance during the initial stages of reintroduction involve catching and transporting the animals to new places, and providing protection for the animals during the period during which their colony is being developed. Such protection should be to the standards typically applied in animal conservation and wildlife preservation - protection from poachers, control of land-use changes, monitoring of changes in population, etc. Beavers should be kept away from areas of extensive agriculture and of infrastructure facilities. Sometimes, however, there is a need for a beaver family to be transferred to another site. Losses of animals are about 1% to 2 % of the introduced population, due to predation by animals such as wolves and cats, and human activities. The reproduction index for beaver populations is about 1.8 to 2 animals. Three years are needed for a beaver to achieve sexual maturity.

As was stated previously, some educational programming or activities may be needed to inform the public about these animals. This programming can be provided by the foresters, who usually are responsible for beaver protection, and who are well acquainted with the local people.

Level of Involvement

Government and its institutions must be involved in supervising the programme a whole, securing the legal status of this animal, backing scientific research, disseminating instructions and information, providing materials, and assisting financially. In addition, local and regional administration involvement is required in the process of introduction, in site selection, covering local costs, providing consultancy, and in adapting and integrating the species into the new area. Local and regional authorities can also assist in local community education.

Costs

Costs include the cost of catching the animals in their natural environment (at sites overpopulated by the species), and transporting the animals to the new site. There are also costs associated with acquiring the necessary scientific expertise, and providing educational services. The direct cost for a beaver family transfer is made up of labour (10 days x 6 persons) and miscellaneous costs like transportation, cages, etc. Additional costs may be incurred as a result of natural migration or when uncontrolled development of a colony threatens human activities (the local administration in Poland, according to the law, is obliged to pay for damages caused by the beavers' activities, as they are a protected species).

Effectiveness of the Technology

Effectiveness depends on the natural physiographic conditions in the area to which a beaver family is introduced. The most effective sites are those with a shallow watertable, such as a flat-bottomed or valley-shaped surface with a low rate of water outflux. Streams, small rivers, and natural, seminatural and artificial water courses with woodland vegetation comprise ideal places for beavers. Under these conditions, reintroduction of beavers is an effective means of enhancing water retention within catchment areas, and of raising the watertable.

Advantages

The main advantage of this technology is enhanced retention of surface water in the area, and the raising of the associated watertable. This additional source of groundwater can be productively used as a freshwater resource (e.g., as in Kielce Voivodship, Poland). Additional advantages include the facts that the beavers are an important biocoenotical element, their activities can efficiently enhance the water purification capacity of the ecosystem and contribute favourably to changes in the local microclimate and biodiversity within the stream system (as has been observed in the Gdansk Voivodship following beaver reintroduction). These modifications contribute also to general changes in the forest environment which are important in improving the fire resistance of the forest, improving soil conditions, and enhancing carbon fixation (as a result of the gradual accumulation of organic matter in the pond). Beavers can be efficiently used in land reclamation schemes (as in Przemysl Voivodship where beaver resettlement and activities in an abandoned gravel pit enhanced the restoration of the natural landscape).

Disadvantages

The disadvantage of this technology is the land-use changes which beavers can initiate. Such changes, in cases of where highly productive agricultural lands are flooded, forest stands decimated, or infrastructure like roads and railway crossings flooded or undermined, may result in conflicts between the beavers and their human neighbours (e.g., as in one not very serious case in Katowice Voivodship).

Further Development of the Technology

Beaver reintroduction in Central and Eastern Europe could be one means of creating better general retention of water within the landscape. In comparison to artificial dams, this technology provides a decidedly more natural, effective and, in the longer term, less expensive approach. In addition, beavers can repair the damage caused by human activities (such as dewatering of bogs and wetlands). Beavers from the Polish populations of Euro-Asiatic species can be slowly reintroduced to many Central and Eastern Europe countries, and could mirror the success of other Polish wildlife species protection efforts, such as the restoration of breeding populations of the European Bison (Bison bonansus), from remnant populations in the Bialowieza forests. In comparison to this example, the beaver has an especial importance because of the role that this animal plays in preserving and augmenting water resources.

Information Sources

Prof. Ryszard Graczyk, Academy of Agriculture, Zootechnical Department, ul. Wojska Polskiego 71c, 60-625 Poznan, Poland, Tel. (48-061) 224901 ext. 28.

Dr Zygmunt Krzeminski, Ministry of Environmental Protection, Natural Resources and Forestry, Department of Nature Protection, Wawelska 52/54, 00-922 Warszawa, Poland, Tel. (48-22) 256204, fax: (48-22) 254705.

Janusz Krupanek, Institute for Ecology of Industrial Areas, ul. Kossutha 6, Katowice, Poland, Tel. (48-3) 154 6031, fax: (48-3) 154 1717, e-mail: jan@amnesia.ietu.us.edu.pl.

Table of conversion factors for metric and U.S. Customary Units

This water-quantity equivalents and conversion factor lists is for those interested in converting units. The right-hand column includes units expressed in two systems-US Customary and International System (metric). Units, which are written in abbreviated form below, are spelled out in parentheses the first time they appear. To convert from the unit in the left-hand column to that in the right, multiply by the number in the right-hand column. Most of the quantities listed were rounded to five significant figures. However, for many purposes, the first two or three significant figures are adequate for determining many water-quantity relations, such as general comparisons of water availability with water use or calculations in which the accuracy of the original data itself does not justify more than three significant figures. Quantities shown in italics are exact equivalents-no rounding was necessary. Regarding length of time, each calendar year is assumed (for this list) to consist of 365 days.

US Customary		US Customary or Metric
Length
1 in (inch)	=		25.4 mm (millimetres)
1 ft (foot)	=		0.3048 m (metre)
1 mi (mile, statute)	=		5280. ft
	=		1,609.344 m
	=		1.609344 km (kilometres)
Area
1 ft² (square foot)	=		0.09290304 m² (square metre)
1 acre	=		43,560. ft²
	=		0.0015625 mi²
	=		0.40469 ha (hectare)
1 mi²	=		640. acres
	=		259.00 ha
	=		2.5900 km² (square kilometres)
Volume or Capacity (liquid measure)
1 qt (quart, US)	=		0.94635 l (litre)
1 gal (gallon, US)	=		231. in³ (cubic inches)
	=		0.13368 ft³ (cubic foot)
	=		3.7854 l
	=		0.0037854 m³ (cubic metre)
1 Mgal (million gallon)	=		0.13368 Mft³ (million cubic feet)
1 Mgal	=		3.0689 acre-ft (acre-feet)
	=		3,785.4 m³
1 ft³	=		1,728. in³
	=		7.4805 gal
	=		28.317 l
	=		0.028317 m³
1 Mft³	=		28,317. m³
1 acre-ft (volume of water, 1 ft deep, covering an area of 1 acre)	=		43,560. ft³
	=		0.32585 Mgal
	=		1,233.5 m³
1 mi³ (cubic mile)	=		1,101.1 billion gal
	=		147.20 billion ft³
	=		3.3792 million acre-ft
	=		4.1682 km³ (cubic kilometres)
Speed (or, when used in a vector sense, velocity)
1 ft/s (foot per second)	=		0.3048 m/s (metre per second)
	=		0.68182 mi/hour (mile per hour)
1 mi/hr	=		1.4667 ft/s
	=		0.44704 m/s
Volume per Unit of Time (discharge, water supply, water use, and so forth)
1 gpm (gallon per minute)	=		0.00144 mgd (million gallons per day)
	=		0.0022280 ft³/s (cubic foot per second)
	=		0.0044192 acre-ft/d (acre-foot per day)
	=		3.7854 l/min (litres per minute)
	=		0.063090 l/s (litres per second)
1 mgd	=		694.44 gal/min
	=		1.5472 ft³/s
	=		3.0689 acre-ft/d
	=		1,120.0 acre-ft/d (acre-feet per year)
	=		0.043813 m³/s (cubic metre per second)
	=		3,785.4 m³/d (cubic metres per day)
1 billion gal/yr (billion gallons per year)	=		0.0013817 km³/yr (cubic kilometre per year)
1 ft³/s	=		2.7397 mgd
	=		448.83 gal/min
	=		0.64632 mgd
	=		1.9835 acre-ft/d
	=		723.97 acre-ft/yr
	=		28.317 l/s
	=		0.028317 m³/d
	=		2,446.6 m³/d
	=		0.00089300 km³/yr
1 acre-ft/yr	=		892.74 gal/d (gallons per day)
	=		0.61996 gal/min
	=		0.0013813 ft³/s
	=		3.3794 m³/d
1 acre-ft/d	=		0.50417 ft³/s
Volume, Discharge or use per Unit of Area
1 in of rein or runoff	=		17.379 Mgal/mi²
	=		27,154. gal/acre (gallons per acre)
	=		25,400. m³/km² (cubic metres per square kilometre)
1 in/yr	=		0.047613 (Mgal/d)/mi²
	=		0.073668 (ft/s)/mi²
1 (Mgal/d)/mi²	=		21.003 in/yr (inches-of rain or runoff per year)
1 (ft³/s)/mi²	=		13.574 in/yr
	=		0.010933 (m³/s)/km² (cubic metre per second per square kilometre)
Mass (pure water in dry air)
1 gal at 15° Celsius (59° Fahrenheit)	=		8.3290 lb (pounds avoirdupois)
1 gal at 4° Celsius (39.2° Fahrenheit)	=		8.3359 lb
1 lb	=		0.45359 kg (kilogram)
1 ton, short (2,000 lb)	=		0.90718 Mg (megagram) or ton, metric

Prepared by John C. Krammer, US Geological Survey (National Water Summary 1990-1991)

The UNEP Water Branch

The UNEP Water Branch was established on 1 January 1996, with the consolidation of the former Freshwater Unit and the Oceans and Coastal Areas Programme Activity Center (OCA/PAC).

A main function of the Water Branch is to promote and facilitate integrated water management, focusing on rivers, lakes and other freshwater systems, groundwater, and the coastal and marine waters into which they ultimately drain, including their living resources. The Water Branch integrates UNEP's water activities across (i) physical boundaries, (ii) disciplines, and (iii) types of water (fresh and marine waters). Particular attention is directed to internationally-shared water systems, including promotion of mechanisms for enhancing international cooperation for their sustainable management and use, as well as assisting riparian countries to undertake transboundary diagnostic analyses and to develop comprehensive management action plans. The focus is on both the scientific and technical issues (water supply and demand, pollution sources, flora, fauna, etc.) And the social, economic, institutional, legal and political issues that fundamentally shape the way in which humans use their water resources.

The Water Branch is UNEP's focal point for its role as secretariat of the Global Programme of Action for the Protection of the Marine Environment from Land-based Activities, including its Technical Coordination Office in The Hague, The Netherlands. The Water Branch also administers and supports UNEP's 13 Regional Seas Programme involving more than 140 coastal States throughout the world, as well as UNEP's activities in support of such initiatives as the Barbados Programme of Action for Sustainable Development of Small Island Developing States, the International Coral Reef Initiative and the Global Plan of Action for the conservation, Management and Utilization of Marine Mammals.

The activities of the Water Branch reflect the objectives and goals of Chapters 17 and 18 of Agenda 21, as well as other chapters of Agenda 21 relevant to the sustainable management and use of water resources, and to the direction provided by UNEP's Governing Council. The Water B ranch supports activities of the International Environmental Technology Centre (IETC) and the Office of Industry and the Environment (IE) of UNEP on matters related to the development and transfer of environmentally sound technologies (EST's) aimed at water resource management. It also participates in inter-agency initiatives involving common UN agency water issues.

To address its tasks and responsibilities, The Water Branch brings together expertise in river and lake limnology, groundwater hydrology, hydrologic engineering, coastal zone management, marine biodiversity, resource economics, monitoring and assessment, environmental technology, environmental law, capacity-building and public awareness. It also works with partner UN agencies, inter-governmental bodies, and international and non-governmental organizations on integrated freshwater and coastal water resource issues.

The Institute for Ecology of Industrial Areas (IEIA)

The Institute for Ecology of Industrial Areas (IEIA) is based in Katowice, Poland. It is a scientific-research institute which dates back to 1972 when it was established by the World Health Organization (WHO) and the Polish Government as an Environmental Abetment Center. In 1992, the Ministry of Environmental Protection, Natural Resources and Forestry issued Decree 54 which gave a new structure to the Institute. Since 1992, the Institute for Ecology of Industrial Areas became a separate and independent scientific-research organization.

The activities of IEIA are primarily related to the following environmental aspects:

-) Air, water, and soil quality control/problem;
-) Waste management;
-) Pollutants migration and transformation in the environment;
-) Assessment of pollutants concentration and their impact on humans;
-) Development of technologies reducing pollutants emission into the environment;
-) Development of modern methods and tools for environmental management;
-) Assessment of agricultural lands suitability for food production;
-) National and European environmental policy analysis;
-) Assessment of Ecosystem conditions;
-) Multi disciplinary system analysis;
-) Air, water, soil and plants pollution;
-) Transboundary pollution;
-) Environmental Impact Assessment;
-) Risk Assessment;
-) Environmental engineering/technology;
-) Clean technologies;
-) Environmental Economics;
-) Water ecology and technology;
-) Solid waste management and reclamation;
-) Life cycle assessment of products;
-) Life cycle assessment of products;
-) Environmental Audits;
-) Analytical methods;
-) Environmental Toxicology;
-) Identification and monitoring of environmental hazards.

The Institute has 129 staff members including 4 Professors, 23 PhDs and 52 MScs. considering chemists, biologists, physicists, mathematicians, agronomists, sanitary engineers as well as chemical and agriculture engineers, geographers, economists and lawyers. A large number of these specialists have extensive experience at international as well as national level.

Institute for Ecology of industrial Areas (IEIA)

6, Kossutha St.,
PL-40-833 Katowice, Poland
Tel: + (48-32) 154-74-13
Fax: + (48-32) 154-17-17
Email: R.Janikowski@ietu.katowice.pl

UNITED NATIONS ENVIRONMENT PROGRAMME - INTERNATIONAL ENVIRONMENTAL TECHNOLOGY CENTRE

Osaka Office

2-110 Ryokuchi koen, Tsurumi-ku, Osaka 538-0036 Japan
telephone: + 81(0)6 915-4580
telefax: + 81(0)6 915-0304

Shiga Office

1091 Oronoshimo-cho, Kusatsu-City, Shiga 525-0001 Japan
telephone: + 81(0)77 568-4586
telefax: + 81(0)77 568-4587

Email: ietc@unep.or.jp
IETC Homepage: http://www.unep.or.jp