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close this bookConducting Environmental Impact Assessment in Developing Countries (United Nations University, 1999, 375 p.)
close this folder10. Case studies to illustrate environmental impact assessment studies
View the documentCase study 10.1 Tongonan Geothermal Power Plant, Leyte, Philippines
View the documentCase study 10.2 Accelerated Mahaweli Development Programme
View the documentCase study 10.3 Tin Smelter Project in Thailand
View the documentCase study 10.4 Thai National Fertilizer Corporation Project
View the documentCase study 10.5 Map Ta Phut Port Project
View the documentCase study 10.6 EIA at Work: A Hydroelectric Project in Indonesia
View the documentCase study 10.7 The Greater Cairo Wastewater Project

Case study 10.1 Tongonan Geothermal Power Plant, Leyte, Philippines

Source: ESCAP Environment and Development Series, Environmental Impact Assessment, Guidelines for Industrial Development, p. 52.

Notes: The case can be used to show how environmental aspects have not been costed

The complete case study, of which this is a part, was adapted by Somluckrat Grandstaff from materials prepared by Beta Balagot, and may be found in Dixon and Hufschmidt (1986). It presents the analysis of the cost-effectiveness of various options for disposing of wastewater from a geothermal power plant built on the island of Leyte in the Philippines. The decision to build the power plant and to tap the local geothermal energy had already been made; it was necessary to decide which means of wastewater disposal from the plant would protect the environment in the most cost-effective manner.

Seven ways of disposing of wastewater are considered in the full case study; the costs of building and operating each are different and each has a different effect on the environment. The analysis examines each option in turn, determining its monetary values and, where possible, its environmental effect.

Not all of the effects on the environment can be quantified and given a monetary value, but those which cannot be quantified should not be ignored in the analysis. These effects are listed in a qualitative manner and taken into consideration when the final decision is made. In this way the decision maker or project designer is presented with a range of information on the actual costs of construction and operation of each option as well as the various effects of each upon the environment.

While each option is subjected to a complete benefit-cost analysis, a more complete presentation would include a benefit-cost analysis of the entire project including the differing options for design of the power plant as a whole as well as those for disposing of wastewater. In this way the economic worth of the entire project, not just one part of it, could have been explored and then compared with other ways of producing electricity.

Background information

In the past the Philippines has been highly dependent on imported crude oil to meet its energy requirements and so has adopted an energy policy which will promote various forms of domestic energy production. These include nuclear energy, hydroelectric power, coal, petroleum, natural gas, and geothermal energy. Geothermal energy is derived from the natural heat of the earth. With existing technology only geothermal reservoirs associated with recent hot intrusive rocks and with vulcanism can be harnessed for the generation of electrical power. High temperature geothermal energy is found in two forms: dry-steam fields, as seen in the geysers of the United States, and hot-water (wet) fields, as seen at Wairakei and Broadland in New Zealand. At present, the Philippines is exploiting only the wet fields, which produce a mix of steam and water.

Exploration at Tongonan in Leyte started in 1973, and in 1978 a potential productive capacity of 3000 MW of geothermal electricity was confirmed. This case study considers Phase 1 of the Tongonan Geothermal Power Plant (TGPP) which has a capacity of 112.5 MW. This power station relies on a wet-steam geothermal resource and produces residual liquids and gases. These have chemical and thermal characteristics that may affect the environment adversely; the degree to which they might do so depends on the rate and frequency of discharge and the method of disposal.

Environmental dimensions

An environmental impact report prepared by Kingston, Reynolds, Thom, and Allardice Limited (KRTA), consultants to the Ministry of Energy and the Philippine National Oil Corporation, indicated that the major adverse effects on the environment would be caused by the disposal of the geothermal waste fluids. The fluids from the Tongonan wells contain more dissolved solids than those from most other geothermal fields; these include chloride, silica, arsenic, boron, and lithium. Arsenic, boron, lithium, and mercury all have known toxic effects on plants, animals, and people, and the full case study examines these effects. The indiscriminate disposal of geothermal wastewater would have severe effects on health and productivity and, to minimize these, the government has set limits to its discharge. Concentrations of arsenic, boron, and lithium in water from the Tongonan wells were found to exceed the limits recommended by the National Pollution Control Commission.

Although the full case study examined the costs and benefits of all seven methods of disposing of the wastewater, our abbreviated version will outline the analysis of only four of them; the analysis of the remainder may be found in Dixon and Hufschmidt (1986).

The data

Seven options for disposal for the wastewater of the plant were proposed:

1. Reinjection

2. Discharge into the Mahiao river without treatment

3. Discharge into the Mahiao River after treatment for the removal of arsenic

4. Discharge into the Bao River without treatment

5. Discharge into the Bao River after treatment for the removal of arsenic

6. Discharge at sea without treatment through an outfall at Lao Point

7. Discharge at sea without treatment through an outfall at Biasong Point.

In option 1, geothermal fluids from separator stations would be piped to reinjection wells within the field. At full capacity the 112.5 MW power plant would need seven such wells. A standby disposal system consisting of thermal ponds and other contingency structures would also be needed. They would be used while the reinjection system was temporarily shut down either for maintenance or for some limited emergency. When the system is shut down for longer periods the stand-by scheme would permit the discharge of chemically treated waste fluids into the river.

Options 2 and 3 involve the direct discharge of waste fluids into the Mahiao River. Before being discharged, the fluids would be retained for a few days in a thermal pond where they may be treated with chemicals to remove arsenic.

In options 4 and 5 waste fluids would be discharged into the Bao River through a pipeline. A thermal pond would also be required for cooling the fluids before releasing them into the river. Option 5 would entail treatment of the fluids in the pond in order to precipitate the arsenic.

Options 6 and 7 involve the selection of an outfall at sea through which to discharge the wastes. Two possible sites have been studied: Lao Point and the Biasong Point. An outfall at the former would involve 22 km of pipeline and at the latter 32 km.

Costs and environmental effects of the options

Each of the seven options has different capital and operations, maintenance, and replacement (OM&R) costs, as well as different effects on the environment. They are briefly described here and 1980 prices are used in the analysis.

1 Reinjection. The construction of seven reinjection wells and the stand-by waste disposal system will take two years. Each well will cost P10 million, or P70 million in all. The construction of a system of pipelines for the separator stations to the reinjection wells will cost P20 million. The stand-by waste disposal system will involve another P17 million. The annual operation and maintenance costs will total P104 million.

Although reinjection is seen as the most ecologically sound method of disposal, it is not yet a well-established technology. In areas where water supplies are drawn from underground aquifers, as in the site of this project, it is important to know the local groundwater hydrology and to monitor carefully any effects of injecting geothermal wastewater.

Reinjection may also lower the temperature and hence the potential energy of the sub-surface geothermal water. In addition, the geothermal liquids at Tongonan contain large amounts of dissolved solids like silica which may clog the reinjection pipes. Such problems could be dealt with by adding chemicals to keep the solids in solution, but the effect of these chemicals may be to create other environmental problems.

2 Discharge into the Mahiao River without treatment. The construction of a thermal pond would take one year and cost P7 million. Operation and maintenance costs are estimated at P43,300 per year.

High levels of arsenic and boron in the untreated waste fluids discharged into the river would affect adversely the productivity of 4,000 hectares of rice fields served by the Bao River Irrigation System. If the irrigation waters are heavily polluted, farmers will probably not irrigate their crops; the consequence is a severe reduction in productivity. Irrigated rice fields yield an average of 61 cavans (1 cavan = 50 kg) per hectare against a yield of 37.9 cavans from unirrigated fields (NIA Region 8 Office, 1980). Production would also be reduced to one crop a year. However, since the rice produced in the Bao River Irrigation System is only a small part of the regional total, it can safely be assumed that these changes in production will not affect local rice prices.

Based on the cost of production data for the area over the 1975-78 period, the nett return per hectare for irrigated rice was estimated at P346 and for unirrigated rice P324, less if irrigation water were made unusable for the entire 4,000 hectares, the economic loss would be as follows:

4,000 ha × P346 per ha × 2 crops = P2,768,000

One crop of unirrigated rice could be grown, yielding the following nett return:

4,000 ha × P324 = P1,296,000

The annual loss, therefore, would be the difference, P1.47 million.

An added environmental cost of discharging untreated wastewater into the river system is the risk to human health and livestock. To evaluate this, the cost of a water purification system that will render the river water safe for domestic use and for drinking was also estimated. The construction of such a system would cost P50 million and cost P15 million annually to operate and maintain.

Estimating the costs to the freshwater ecosystem is more difficult, since there are no data on the economic value of the fishing along the river. However, another environmental cost which can be estimated will be the pollution of the delta, which will affect the marine fisheries of the area. The delta or mangrove area of Ormoc Bay plays an important role in sustaining productivity in the adjoining fishing grounds because it is the feeding and spawning ground of several species of fish.

Fishing is an important industry in the Ormoc Bay and Camotes Sea area. Based on 1978 figures, the nett return from fishing was estimated at 29 percent of the gross return from the catch. Although the annual value of the fish catch varied from year to year depending on the actual size of the catch and on market prices, a gross value of P39.4 million was taken as representative. If this fishery was lost as a consequence of heavy-metal contamination, the annual economic loss would be about P11.4 million (P39.4 × 0.29). It is assumed that the capital equipment could be sold or shifted to other areas, but that the lost catch would not be replaced by additional fish catches elsewhere.

3 Discharge to Mahiao River after treatment. A thermal pond will be constructed at a cost of P7 million and completed in one year. In addition to the regular operation and maintenance costs of the pond itself, there will be further costs for the treatment of arsenic. These will amount to P4 million per year for each of the 15 producing wells. There are no scientific studies of the interactive effects of boron and arsenic on a rice field: hence there is no basis at this point for determining whether or not the effects on productivity will be less severe if the arsenic is removed. There may also be some residual effects on the aquatic ecosystems, but these are not identifiable.

Capital costs for a water purification system are estimated at P25 million and annual operating and maintenance costs at P7.5 million.

4 Discharge of untreated effluent into the Bao River. A thermal pond will cost P7 million. A pipeline some 6 or 7 km long would take two years to build at a cost of P13 million. Operation and maintenance costs will be P6.2 million a year. Since the point of discharge will be downstream from the diversion for irrigation, the area of the Bao River Irrigation System will not be affected by the waste fluids.

A water purification system will be needed to serve the residents along the reaches of the Bao River below the point of discharge. Its construction will take two years at a cost of P15 million. Annual operation and maintenance costs are estimated at P4.5 million. The information on fishery productivity used in option 2 will be used in this option to estimate the costs to the marine environment.

5 Discharge of treated effluent into the Bao River. The capital costs will be the same as in option 4. However, the operation and maintenance costs will be higher. The annual cost of treating the waste fluids for arsenic is estimated at P4 million per producing well. The cost of establishing a water purification system will be lower when the fluids are treated for arsenic. The capital cost is estimated at P7.5 million, but the time needed for construction remains the same. Operation and maintenance costs of P2 million are expected.

6 Discharge into the sea with an outfall at Lao Point. This scheme will need a 22 km pipeline which will take two years to build at a cost of P45 million. Its annual operating and maintenance cost will be P41.8 million. The disposal of wastewater at sea may affect the productivity of coastal fishing as well as the commercial fishing in Ormoc Bay and the Camotes Sea. Not enough information is available, however, to quantify these effects.

7 Disposal at sea with an outfall at Biasong Point. For this option a 32 km pipeline would be constructed. This would take two years and would cost P65 million. Operation and maintenance costs would come to P60.8 million per year. The productivity of marine fishing may be affected. In estimating the effects of options 6 and 7 on marine productivity, hydrological and dispersal patterns in Ormoc Bay and the Camotes Sea should be taken into account.

Analysis of the options

There is enough information available to carry out an analysis of some of the major environmental effects of the various options. While the overall approach is that of cost effectiveness analysis, individual effects are usually valued using direct productivity changes based on market prices.

The assumption is therefore that market prices can be used to value agricultural and fishery production: that is, that there are no major distortions requiring the use of shadow prices. This may or may not be correct for the Philippines, but in this example no price adjustments are made. A similar assumption is made in the case of imported capital equipment used in the disposal systems and for petroleum products used to power the pumps and other equipment involved. Again, if major distortions like subsidies, foreign exchange controls, or capital rationing exist, then shadow prices would be needed.

The present value of the direct costs and the associated environmental costs for each of the proposed wastewater disposal schemes are calculated with a discount rate of 15 percent and an estimated project life for the geothermal power plant of 30 years. Table 10.1 presents the calculations of direct capital, OM&R costs for options 1, 2, 3, and 6. Table 10.2 presents the calculation of environmental resource costs for the same options.

The results of these calculations for all seven options are summarized in Table 10.3, without including the values of environmental costs. Option 4, in which untreated waste fluids are discharged into the Bao River, would have been chosen because it entailed the lowest direct cost. Once the environmental effects are valued and added to the direct cost, the total direct and indirect measurable costs are obtained.

Options 3, 5, 6, and 7 can be rejected because they are all relatively costly compared to options 1, 2, and 4, among which the choice would now seem to lie. If the decision is based strictly on measurable costs, then option 4 is the cheapest scheme. However, both options 4 and 2 may seriously contaminate the marine ecosystem with unknown and unquantifiable results. Option 2, which calls for the discharge of untreated waste into the Mahiao River, is rejected because not only does it pollute, like option 4, but it is also more expensive. In contrast, the main non-quantifiable effect of option 1 is the possible loss of energy from the lowering of the steam temperature. Hence reinjection becomes the most desirable method, although its total measured costs are slightly higher than for option 4. In this case a slightly larger measured cost in option 1 is preferred over the greater environmental uncertainty inherent in option 4, the least cost alternative.

Further Reading

J. A. Dixon and M. M. Hufschmidt, eds., Economic Valuation Techniques for the Environment: A Case Study Workbook, Johns Hopkins University Press, Baltimore, 1986.

Case study 10.2 Accelerated Mahaweli Development Programme

Notes: This case study can be used to make matrices and grade them.

Name of project: Accelerated Mahaweli Development Programme.
Type of environmental analysis: Full-scale EIA.
Project location: Mahaweli basin in Sri Lanka.
Type of project: Rural socio-economic development.

Table 10.1 Calculation of direct capital and OM&R costs of alternative wastewater disposal options (in Pesos)

Part of project


Option 1 -Reinjection

1 Construction (2 years)

Million Pesos

(a) reinjection wells


(b) pipeline


(c) stand-by system



Construction cost per year


2 Operation and maintenance per year


Cash flow:





million Pesos




Present value at 15 percent discount rate

Year 1 = 53.5 × 0.8696


Year 2 = 53.5 × 0.7561


Years 3-30= 10.4 × 4.9405


Present value of total direct cost


Option 2 -Discharge to Mahiao River without treatment

1 Construction

(a) thermal pond (1 year)


(b) Water supply system (2 years)


2 Operation and maintenance per year

(a) thermal pond


(b) water supply system


Cash Flow:





million Pesos










Present value at 15 percent discount rate

Year 1 = 25 × 0.8696


Year 2 = 32 × 0.7561


Years 3-30 = 15.0433 × 4.9405


Present value of total direct cost


Option 3 -Discharge to Mahiao River without treatment

1 Construction

(a) thermal pond (1 year)


(b) Water supply system (2 years)


2 Operation and maintenance per year

(a) thermal pond


(b) arsenic removal for 15 steam producing wells (at 4 million Pesos each)


(c) water supply system


Cash flow:





million Pesos











Present value at 15 percent discount rate

Year 1 = 12.5 × 0.8696


Year 2 = 19.5 × 0.7561


Years 3-30 = 67.5433 × 4.9405


Present value of total direct cost


Option 6 -Discharge at sea with an outfall at Lao Point

1 Construction

(a) Pipeline (2 years)


2 Operation and maintenance per year


Cash Flow:





million Pesos




Present value




Present value of total direct cost


Brief description

The programme includes the construction of storage and irrigation facilities sufficient to supply water for the cultivation of 128,000 hectares of new lands and for the upgrading of 32,000 hectares of existing agricultural lands in the irrigation systems designated as A, B, C, and D.

Approximately 175,000 families will find permanent employment in agricultural or agricultural-related activities. New and improved cultivation will produce more than 600,000 tons of rice and other crops annually and therefore meet the current import demand for rice as well as satisfy a major portion of future demands. In addition, the proposed reservoirs will substantially increase hydroelectric power output for the country.

Table 10.2 Calculation of environmental and resource cost of alternative waste-water disposal options (in Pesos)

Option 1 - Reinjection

The environmental cost cannot be estimated, although it involves: (i) possible loss of potential energy; (ii) treatment cost for dissolved solids in reinjection pipes; and (iii) additional environmental problems from chemicals used to keep the reinjection pipe from being clogged.

Option 2 - Discharge to Mahiao River without treatment

The environmental effects in this case include both the quantifiable and the non-quantifiable consequences, namely:

1 rice productivity: 4,000 ha per season serviced by BRIS;
2 river fishery: no data;
3 stock health;
4 laundry, bathing and human health; and
5 sea ecosystems.

Quantifiable effects:

Value of rice production loss:
Total rice area = 4,000 ha
Return/ha for irrigated rice
(average 1975-8) = 1,838 - 1,492 = P346

Annual loss if irrigation water cannot be used due to heavy contamination

= 4,000 × 346 × 2 - (4,000 × 324)
= 2,768,000 - 1,296,000
= P1.47 million

Present value of rice loss at 15 percent discount rate (years 3-30)

1.47 × 4.9405 = P7.26 million

Value of fishery product loss:
assuming total loss of product currently obtained

From data on average cost and return profile of fishing operation in Leyte, the nett return

= 6,914 - 4,918
= 1,996
= 29 percent of gross return

Total value of fishery product in the Camotos Sea and Ormoc Bay in 1980

= P39.4 million

Annual loss of fishery product = 39.4 × 0.29 gross return

Present value of fishery loss at 15 percent discount rate (years 3-30)

11.4 × 4.9405 = P56.3 million

Non-quantifiable effects:

River fishery, stock health, human health, loss of water use for laundry and bathing, effects on the marine ecosystems, plus possible family dislocation.

Option 3 - Discharge to Mahiao River with treatment

Environmental effects:

1 rice productivity unknown;
2 river fishery; no data;
3 stock health, laundry, bathing and human health; non-quantifiable but less than alternative 2; and
4 marine ecosystems; unknown.

Option 6 - Disposal at sea

Environmental effects: unknown effects on marine ecosystems.

Table 10.3 Cost of waste disposal under alternative schemes (in million Pesos)


Direct cost

Environmental cost

Total measured cost

Non-quantifiable or non-measured costs





Energy loss

Mahiao discharge


Rice 7.3
Fishery 56.5


Freshwater fishery, stock health, laundry, bathing uses, human health, sea ecosystems

Mahiao discharge



Rice production and a lower loss on items in alternative 2 with the exception of sea ecosystems

Untreated Bao discharge


Fishery 56.5


Freshwater fishery, stock health, domestic use, human health, sea ecosystems

Treated Bao discharge




Less than alternative 4

Lao Point




Non-quantifiable but high

Biasong Pt.




Non-quantifiable but high

Under the Accelerated Programme, the total live storage capacity of the major reservoirs is 2,555 million m3. With full development of the Rotalawels and Moragahakands reservoirs, a total of more than 4,000 million m3 of water will be available for irrigation and power generation.

In addition to the proposed dams and reservoirs, the major canal (Minipe Right Bank Canal) and a tunnel will be constructed to divert water from the Mahaweli Ganga at Minipe to the Ulhitiya Oya and the Maduru Oya reservoirs for irrigation of Systems B and C. Also, a barrage (Kandakadu Anicut) may be built in the Mahaweli Ganga near Manampitiya to divert Mahaweli water to System A.

The areas which will be irrigated under the Accelerated Programme could be tabulated. These data could be compiled from the most recent estimates from ongoing feasibility studies for System A, B, C, and D. When fully developed, the Accelerated Programme will provide irrigation supplies for the cultivation of 80,800 hectares of new lands (mostly for paddy) and for the improvement of 14,350 hectares which are in existing irrigation schemes.

The proposed settlement plan for the Accelerated Programme includes the clustering of house lots into a hamlet which will be located not more than 1-2 km from irrigated allotments. Each hamlet will be comprised of about 100 settler family units, each allotted 0.4 hectares (one acre) of upland as a house lot and vegetable garden and 1 hectare for paddy cultivation. About four or five hamlets will be consolidated into a village, and four village centres will form a township. All the necessary infrastructure such as roads, schools, hospitals, etc. will be provided by the government, and it is expected that the settlers will establish other facilities such as a shopping centre, community centres, etc. through their own efforts. In addition to the present inhabitants, the Accelerated Programme area will accommodate a population of about one million people.

Pertinent reports

Two EIA reports were prepared relating to the Mahaweli project: (a) "Environmental Assessment, Accelerated Mahaweli Development Programme'', by TAMS for Ministry of Mahaweli Development of Sri Lanka/USAID, Oct. 1980; and (b) "Environmental Assessment of Stage 11 of the Mahaweli Ganga Development Project'', USAID, Sept. 1977.

The present study is based essentially on the former reference.

Environmental study area

The portion of the Mahaweli Ganga river basin which includes Kotmale, Victoria, Randenigala, Ulhitiya Oya, and Madura Oya reservoirs and their catchments and downstream irrigation areas, plus the Rotalavela and Moragahakanda reservoir systems as applicable.

Environmental study team

Data not included in EIA report.

EIA budget adequacy

Data not included in EIA report.


The EIA classifies the environmental resources of the study area into three categories: (i) terrestrial environment, (ii) aquatic environment, and (iii) human environment. The human environment category includes three subcategories, "social profile'', "cultivation practices'' (including pest control), and "public health''.

Existing environmental conditions

The EIA presents detailed information on the existing environmental conditions. Some pertinent information, according to classifications used, is as follows.

Terrestrial environment

The climate is hot and humid, with two annual monsoons of 1,650 mm rain. In the dry zones (to be serviced by the proposed irrigation system) evapotranspiration usually exceeds rain.

Over the past 25 years, community (town) areas increased from 1,000 to 4,000 ha, intensive agriculture decreased from 87,000 to 63,000 ha, and forest areas have reduced by half. Present land uses indicate chena cropping occupying 23 per cent of the land within the project irrigation service area (ISA).

About 28 per cent of the proposed ISA is forested (tropical dry mixed evergreen forest). All former forest reserves were released for development and have been largely cleared, and rapid encroachment on the remaining forest is continuing (and will be accelerated by the proposed irrigation).

The region's wildlife has been exceptionally diverse with a variety of habitat including marshes (villus) and grasslands as well as forests. Several wildlife reserves are within the project area (wholly or partly) and others are nearby. A number of the species are endemic and are threatened.

Aquatic environment

The Mahaweli Ganga is the largest river in Sri Lanka, and the project is based on utilization of this resource. Groundwater is very limited in the project area.

The water quality of project area rivers is well suited for irrigation and other human use purposes (low salinity, low sodium absorption ratios).

Most of the fish catch is from irrigation tanks (about 180 kg/ha/year). Inundation (floodplains) fisheries amount to about 50 kg/ha/year. Riverine fishing is of the subsistence type. Total annual project area catch is about 1,850 tons. In addition there are substantial fisheries on both the Maduru Oya and Mahaweli Ganga rivers. Fish farming is very limited.

Per capita fish consumption has declined from 11.4 kg in 1972 to 10.4 kg in 1978. Because this is important to rural nutrition, one project goal is to increase this to 20 kg/year. Another goal is to improve the income of fishermen families, many of whom are landless.

The wetland in the project area includes some 60 villus (marshes) ranging from 10 to 900 ha in size, distributed throughout the total Mahaweli Ganga floodplains area of about 12,800 ha. The villus are highly productive biologic communities and a high-quality wildlife habitat. They are commercially important for the grasses produced, which are enough to support 1 head of livestock per ha of villa.

Human environment

The project area is sparsely populated, and farmers are engaged mostly in rice cropping below village tanks or upland crops grown in chena cultivation. The population is predominantly Sinhalese, average family size is about 5, and "encroachers'' are plentiful. More than half the families earn less than Rs 3,000/year.

In traditional villages in the project area, farmers operate usually a 0.2 to 0.6 hectare plot of lowland below the village tank, a small rainfed homestead plot, and an area of rainfed upland shifting chena cultivation. On the irrigated lowlands, rice farming is developed as a predominant monoculture, especially within the large tank systems. On some well-drained parts of the lowlands, chillies, onions, and vegetables are also grown. Paddy yields from rainfed and irrigated sources average about 2.5 tons/hectare/year. The availability of water is a major factor affecting yield levels as well as cropping intensity. Where a reliable water supply is available, paddy yields are well above 3.0 tons/hectare, occasionally reaching 4.5 tons/hectare.

On the rainfed homestead plots, various perennials and vegetables are grown along with bananas, pineapples, mangoes, papaya, and other tropical fruits. The chena cultivation focuses on annuals, mainly cereal and root crops, including pulses, millets, vegetables, tobacco, and often rainfed paddy. Most of the encroachers who have entered the project area in the past few years are subsisting on chena cultivation.

The most serious insect pest for rice in the project area is the brown planthopper. Other major insect pests include rice thrips and paddy bug. Sugarcane suffers considerable damage from shoot borers and smut. In addition, the mania and rose ringed parakeets cause an estimated 5 per cent loss to rice crops in the project area. Wild boar and elephants are also responsible for substantial crop losses.

Diarrhoeal diseases are common, due to inadequate sanitation. Of the vector-borne diseases, malaria is considered of primary project concern. However, malaria incidence has been decreasing due to anti-malaria programmes implemented over the past decade.

Significant environmental effects from project

Terrestrial environment

Watershed erosion is severe, but nevertheless reservoir siltation will not be enough to impair reservoir operations over the project design period (50 years).

Conversion of downstream forest/scrub land/chena areas to paddy will of course eliminate considerable wildlife habitat. Also, decreased river flood flows will convert much of the villus area into comparatively poor grazing area.

Increased encroachment seems inevitable both for "squatter land'' and for fuel. Project implementation will also make use of new lands for irrigation some of which has been valuable wildlife habitat. However, these same encroachments seem likely to occur eventually in any case. The present project will accelerate the process.

Aquatic environment

Under the Accelerated Programme, a large amount of the water diverted from the Mahaweli Ganga will be delivered to irrigation systems outside of the Mahaweli Basin. Of the remainder, only about 20 per cent is likely to re-enter the Mahaweli as irrigation return flow. Overall, the volume of flow in the river will be reduced by about 50 per cent. Wet as well as dry season flows are expected to decrease in the Mahaweli; however, future flows during the dry months should increase slightly in the Maduru Oya due to the planned transbasin diversion into System B. Flood peaks in the Mahaweli Ganga will be considerably reduced by the surcharge storage in the new reservoirs.

With the conversion of forests to agricultural land, the future surface run-off is expected to increase. However, the effect on stream flows should not be significant, because the forested area to be cleared is relatively small in comparison with the total drainage area of the Mahaweli Basin. In addition, the increased run-off will be retained by rice paddies and eventually lost to evapotranspiration.

In a few localized areas water quality in return flows may deteriorate significantly, preventing their immediate reuse for irrigation. This may occur where salt accumulates due to improper drainage or where sonic sub-soils exist which, when irrigated, release sodium into drainage waters. However, in most of the project area, adequate drainage and the flushing action of heavy monsoon rains should limit salt build-up in soils or high sodium concentration problems.

Generally, surface water and groundwater in the project area should be suitable for livestock drinking as well as for swimming, bathing, clothes washing, and related domestic uses. However, the use of these waters for bathing or swimming and for human consumption will depend upon the provision of protected water supplies and adequate sanitation facilities.

Potential fish yields calculated for the proposed reservoirs clearly indicate that the deep up-country reservoirs are likely to be much less productive (20 to 30 kilograms/hectare/year) in terms of fish output than the shallower low-country ones (100 to 300 kilograms/hectare). Yields from the reservoirs will greatly exceed existing river yields both on a unit and total area basis. The total nett yield for the major proposed reservoirs is estimated at about 2,550 tons/year.

The presence of a series of dams on the main river will also block upstream spawning migrations of the massier. This, combined with the inability of the massier to adapt to reservoir habitats, will probably result in a significant reduction in the population of this species within the Mahaweli Ganga. Other species which may be adversely affected by interference with migratory movements include eels, two species of barbs, the endemic mountain labeo and the freshwater shrimp Macrobrachium.

The reduction of floodplain and associated villa areas will result in a corresponding loss to fisheries resources. The total loss in terms of fish yield is estimated at 320 tons/year. A further non-quantifiable adverse impact would be the reduction of floodplain spawning and nursery grounds for a number of fish species which inhabit rivers, streams backwaters, ponds, and tanks of the entire Mahaweli Ganga system. Overall, there will be a nett increase in potential fish yields from project area waters of about 2,140 tons, or a gross economic benefit of about Rs 8.6 million annually.

There will be a reduction in area for livestock grazing in the villus and a decrease in the villa carrying capacity from 1.0 to 0.75 animal units per hectare. The total carrying capacity for the project area villus will be decreased by more than 60 per cent, to a level of 2,880 animal units per grazing period. The decrease in floodplain villa area will result in a total loss in quantifiable economic benefits of about Rs 5.7 million annually. This includes losses to fisheries, grazing, and associated dairy production.

Any of the new reservoirs, irrigation canals, drainage systems, or paddy areas may be susceptible to aquatic weed infestation, chiefly from water hyacinth, floating ferns, or cattails. Particular areas of concern would be where eutrophication may be increased due to the accumulation of nutrients from run-off or return flows. Consequently, small downstream tanks and villus, the lower part of the Mahaweli Ganga with its reduced flow, and the shallow Kandakadu Barrage are likely to experience a continued infestation of water weeds.

Human environment

A major social impact of the Accelerated Programme will involve the transition from small isolated village societies to production-oriented large-scale colonization schemes. Implicit in the model of transition is the modernization of rural society with the attendant loss of traditional values and social cohesion within small kinship-based villages.

The population in the project area will be increased by about 1 million people. Current project area residents who are over eighteen years of age and have an agricultural background will have priority in the resettlement planning. The principal social benefits will accrue to settler families who stand to gain land and irrigation waters; this is also the major benefit perceived by project area residents as well as potential settlers from other regions who are applying for allotments.

An important attitude prevailing among future settlers is that the 1 hectare paddy land allotment, irrigated for two full seasons, will represent an improvement from present landholding. However, planning calls for traditional inheritance and kinship roles to be abandoned with respect to the mechanisms for landholding and its acquisition. This may prove difficult to enforce; studies elsewhere indicated that allotted land was leased, mortgaged, and given in tenancy to relatives within the first year of cultivation.

As in previous colonization schemes, the Accelerated Programme will also face the problem of employment for the second generation of the farmer settler families. Some of the second generation offspring can provide employment in non-farm sectors; however, not all of them can be accommodated in this manner. This may lead to fragmentation of paddy land and home plots or the further encroachment on undeveloped lands within or adjacent to irrigation blocks. Many of the present chena farmers in the area are second generation settlers from other schemes who have encroached land in order to be in a position of acceptance in the new programme.

At the proposed reservoir sites, especially Victoria and Kotmale, a total of 25,000 to 30,000 residents will have to be relocated. The affected people have accepted the inevitability of relocation, but there is a general resentment and a sense of loss of ancestral homes for those who have experienced little geographic mobility moving to nearby estates or into the Mahaweli area, which would benefit smaller landholders. However, most are concerned about how they can support themselves in the period it will take to replace their lost tree crops and paddy.

A major benefit of the Accelerated Programme will be to increase agricultural output. The main focus will be on rice production. The single rice crop intensity presently achieved per year under rainfed conditions or small tank irrigation will be increased to obtain double cropping. Approximately 8 tons per hectare of paddy will be produced from the two crops grown per year on the newly cultivated lands. Moreover, much of the existing irrigated paddy land will receive supplemental water to permit additional cropping intensity.

One constraint to the high intensity rice monoculture envisioned will be the farm labour supply. Another problem will be pest control. Since there are no geographical barriers to prevent the movement of any known insect pest or plant disease, it is anticipated that the crops proposed for the project area will be susceptible to damage from the same pests found in other parts of the island. Intensity of pest activity for the new rice growing areas is expected to be manifested by an increase of brown planthopper and sheath blight.

Extensive sections of wildlife habitat will be removed and thus eliminate a substantial amount of natural predator control. This, coupled with the increase in cultivated areas and the intensification through double cropping, will necessitate a significant increase in the use of insecticides, fungicides, and herbicides.

With the substantial increase in population which is anticipated in the project area, there will be an inevitable spread of a number of viral and parasitic water-borne communicable diseases. This will be exacerbated by the lack of basic health education combined with the cultural practices of the people. They would be expected to continue their present utilization of the same water supply for drinking, bathing, and waste disposal which would be very conducive to the spread of gastroenteritis, hepatitis, dysentery, and other water-borne diseases. This condition will be worsened if suitable water supply and sanitation facilities are not provided, or, perhaps more importantly, not maintained.

Reduced river flows and seepage from irrigation channels in the project area will enhance the formation of small pools which will increase the breeding potential of the principal malaria vector, Anopheles culicifacies. Malaria incidence will undoubtedly increase in the region. The present intensive control programme involves the risk of producing malathion-resistant A. culicifacies which could trigger an epidemic until new controls are decided. This vector has already developed resistance to malathion in India.

Among the other diseases, dengue fever, chikungunya virus, scrub typhus and bed bugs are all likely to spread in the project area. For the present, neither filariasis nor schistosomiasis would be expected to spread as a result of project implementation.

Rabies, tetanus, accidents and snake bites are also likely to increase, particularly in the early years of construction and clearing. Tetanus may be a serious problem for construction workers due to its prevalence in the project area soils. Existing health facilities in the Mahewali region will, of course, be too limited to accommodate the health needs of the additional population.

Overall, dietary patterns and nutritional quality should improve for the incoming settlers due principally to increased food availability and an increased standard of living. However, one potentially serious problem may be an insufficient supply of animal protein to meet nutritional requirements for the general maintenance of good health. The supply of dairy products to the project area may be limited since the grazing area may be reduced. On the other hand, increased freshwater fish production could contribute significantly to meet this need for animal protein.

Measures for offsetting adverse effects

Coordinating agency

Establishment of a National Coordinating Agency for Natural Resources, along with an Environmental Protection Agency, is recommended for furnishing institutions capable for follow-up implementation of needed environmental protection measures.

Watershed management/forests

A package of watershed soil conservation measures is recommended, including reforestation, establishing timber and fuel wood plantations, rehabilitating abandoned plantations by conversion to upland cropping, plus engineering measures for erosion control. The fuelwood plantations would utilize local village participation. A "Mahaweli Catchment Redevelopment Law'' would be enacted for establishing a new National Forest Authority. Included in the package would be the preparation of a systematic plan for continuing logging and clearing operations.


New wildlife reserves are to be established in those "high quality wildlife habitat'' areas not needed for agricultural purposes. In addition, to compensate for loss of habitat in the Mahaweli region, a series of six large continuous reserves/parks are recommended in and around the project area. These include the Somawathie National Park (especially important for elephants), Mahaweli Conservation Park (bird sanctuary), and Wasgomuwa National Park (endangered vertebrate species). A package of institutional improvements is recommended, including establishing a National Department of Wildlife Conservation, and authorizing a detailed study for planning the proposed new park and other reserve systems.

Wetlands and weed control

Within the context of the measures described above, the remaining villus and mangrove swamps will be preserved to the extent possible. A programme will also be developed for use of practicable methods for controlling aquatic weeds.

Fisheries development

The recommended action programmes include: (i) establishing fisheries management systems for the new reservoirs, (ii) a series of pilot project fish farms to determine the best approach for achieving markedly expanded aquaculture, and (iii) strengthening of the ongoing "tank'' type of aquaculture using relatively low level technology including construction of a centralized hatchery.

Downstream water and soil management

These recommendations include: (i) establishment of a water management system in the ISA, (ii) control of land clearing operations to minimize loss of topsoil and subsequent erosion, (iii) use of contour techniques in upland areas including plantings and terracing, (iv) establishment of riverbank forest reserves, (v) use of an integrated pest management approach, and (vi) establishing a multipurpose water and soils monitoring programme including a salinity intrusion survey and periodic water quality monitoring.

Health and sanitation

The recommendations include: (i) provision of an adequate rural water supply system, (ii) control of malaria and other vector mosquitoes through strengthening of the existing programmes, (iii) immunization procedures to be used during the construction, and (iv) strengthening of primary health care resources.

Social considerations

The recommendations include: (i) establishment of a regional planning and socio-economic studies unit, (ii) establishment of a settler orientation programme, (iii) studies for developing guidelines for managing a variety of social problems, including special attention to the poorer population sectors such as fishermen's families and agricultural labourers, and evaluation of tourist potentials, and (iv) strengthening of agricultural extension services.

Land use planning

This recommendation is for preparation of an optimal land use scheme which allows maximum agricultural development commensurate with preservation of forests/wildlife, including detailed mapping of non-arable lands and associated studies including evaluation of grazing potentials.

Priorities and scheduling

A tentative scheduling is outlined, showing when the various recommendations are to be undertaken as related to the various stages of project implementation.

Environmental monitoring

While the study does not deal with the need for comprehensive environmental monitoring, it does recommend a comprehensive "multipurpose soils and water monitoring programme'' in the project irrigation service area. Other monitoring is to be included under the various recommended sector programmes.

Concluding remarks

The recommendations of the EIA for achieving desired environmental protection measures as part of the overall plan are very comprehensive, so much so that implementing them will require major alterations in the existing national government structure and policies.

Case study 10.3 Tin Smelter Project in Thailand

Notes: This case study can be used by trainees to make mitigation plans and discuss post-project monitoring.

Name of the project: Environmental impact assessment for tin smelter project.

Type of environmental analysis: EIA.

Type of project: This is a metal-refining industry. The manufacturing process essentially involves heating the ore and utilizing the difference in melting point temperature (alloy formation involves slightly different methods) for obtaining the separation of the various components including the production of the tin metal of over 99.9 per cent purity from the original ore concentrate of approximately 73-75 per cent purity.

This is the only tin-smelting and refining plant in Thailand. It is capable of producing about 40,000 Mt/year of refined tin, which is 20 per cent of current total world production. A number of by-products are also produced, including tin-lead.

The industry produces three types of waste: namely liquid, solid, and gas. Domestic wastewater, laboratory wastewater and plant surface run-off are the main liquid wastes. Heavy metals such as Fe, Pb, Ta, Nb, Ti, Sn, Al, Zi, and Cn are the main heavy metal pollutants. Solid waste management does not pose any significant problem. Some amounts of toxic heavy metals, including Pb, As, Sb, and Bi, are emitted to the atmosphere. Also the sulphur present mainly in the fuel can generate significant quantities of SOx. Thus air pollution is the most threatening hazard at a tin smelter.

Project location

The tin smelter is located at the southern promontory of Ao Kham Bay on the southeast shore of Phuket Island, which is about 6 km south of Phuket town though 12 km by road. The plant is located adjacent to the tin ore processing facility. The plant is bounded on the east and south by the sea and the west and southwest by coconut groves. The total area of the plant is 5.8 acres.

Reports on pertinent studies

See References 1-4, page 305.

Environmental study area

The study area includes the land mass within approximately a 5 km radius of the plant. This area has been determined to cover more than adequately any resources which may be significantly affected by the tin smelter operation.

EIA team

The EIA team consists of two co-managers, with one project field engineer, two air quality experts, one socio-economist, one water quality expert, and one ecologist, with support staff.

EIA budget adequacy

Adequate budget was provided.


The methodology for preparing the EIA is that recommended by NEB (Ref. 5, p. 305). It is based on the methodology developed by the Battelle Institute/United States Army Corps of Engineers. In this methodology environmental resources are classified and evaluated in four general headings, namely: (a) natural physical resources, (b) natural ecological resources, (c) human use of economic development resources, and (d) quality-of-life values. In addition to estimating effects of the tin smelter operations on these resources, and identifying, delineating, and quantifying adverse effects, the method includes preparation of recommendations for minimizing unavoidable adverse effects and for offsetting these by positive enhancement measures.

To supplement the data from different sources, a number of field surveys were made covering all specialized environmental impacts (including socio-economics, wildlife, flora, and fauna, plus a sampling analysis of wastewaters, drinking water quality, health status of the workers, etc).

Existing environmental conditions


Based on discussions with long-time residents of Phuket, it appears that prior to the construction of the tin smelter (about 20 years ago), the study area was sparsely populated, with land use including some coconut groves, rubber plantations, and secondary forest. Agricultural development coupled with population growth has resulted in increases in cultivated crops as well as coconut and rubber plantations and thus created a more densely populated agricultural zone.

Environmental concerns

During the past 20 years (the duration of tin smelter operations), several new families have moved into what was previously a sparsely inhabited area. This can be expected as a result of increased economic opportunities from the industrial development, improvements in transport/access, etc. It may also be expected that the increased population may result in increased frequency and opportunities for complaints. Complaints on record cover blasting noise and smoke.

Blasting noise from slag granulation: frequently 2-3 times/day, mostly occurring during night; continuous blasting noises (> 100 times in each duration); disturbs relaxation time of surrounding people, patients, children, and babies; and caused different levels of vibration to houses depending on distances - creating damage to items, e.g. mirrors, window panes, and roof tiles.

Smoke from blasting and stacks: aesthetic nuisance (clothes and houses got dirty, bad odours); and fear of illness due to bad odours.

Environmental base map

The environmental base map (EBM) shows the plant and its environs. The EBM shows all potentially sensitive environmental resources, that is any resource which might be significantly impaired by the plant operations, including waste emissions.

Environmental effects from project

Adverse effects on physical resources

Air quality: odour and dust nuisance during certain hours on some days (though the modelling and stack emissions indicate that the tin smelter may not be the source); reduced yields from fruits from coconut plantations; and visible damage to leaves.

Noise pollution: noise has affected most of the residents of the villages.

Adverse effects on water resources

The wastewaters discharged from the laboratory and canteen without any treatment are unsightly and these waters exceed Ministry of Industry (MOI) standards for some parameters.

Adverse effects on human use values: agriculture

The smelter air emissions have caused significant reductions in yields of coconut plantations. Also the toxic effects of groundwater and soil polluted by tin dredge tailings which have been panned or stored in the coconut groves by local villagers have caused the plants to yield less.

Adverse effects on quality-of-life values: socio-economics

About 90 per cent of the respondents at Ban Ao Makhan and 100 per cent at Ban Laem Phan Wa Wee were negatively affected by noise and dust emissions.

Positive effects on human use values

Water supply: the tin smelter operations created beneficial impacts on water supply in that the smelter made arrangements for local villagers to utilize the groundwater supply developed by the tin smelter.

Mining/mineral resources: the operation of the tin smelter has an obvious beneficial impact on local, regional, and national mineral resource development and subsequent beneficial economic impacts.

Quality-of-life values: wage earning forms the major proportion of household income in the area. The smelter has created job opportunities and other related employment opportunities for the local villagers. These indicate long-term benefits for the people in the area.

Land prices in the vicinity have increased because of the presence of the industry. Economic benefits include benefits of increased earning and creation of jobs for the workers and their families as well as the gross regional product, and overall economic benefit to the nation.

Summarized projected effects

The impacts of the smelter operations are both beneficial and adverse, with the beneficial impacts outweighing the adverse. The primary beneficial impact is the economic benefit which is believed to play a major role in the villagers' good primary healthcare. In addition, the provision of water supply for many villagers is a primary beneficial impact.

The adverse impacts are related to air and noise pollution from the plant. Apprehension naturally results regarding health when one believes that air pollution is causing damage to vegetation, leaving deposits of dust at the living quarters, and may be damaging to human health. These fears may or may not be justified. The health data from the local clinic do not indicate any difference in the health condition.

Measures for offsetting adverse effects

Air quality

The cyclones, baghouses, and electrostatic precipitator are generally performing well. Consideration should be given to undertaking the corrective maintenance measures for the electrostatic precipitators (ESP) recommended by Research Cottrell as these measures will ensure a longer and more efficient operating life of the ESPs and should further reduce the frequency of tripping of the ESPs; bag replacement and maintenance should be improved, and the performance closely monitored; and consideration should be given to upgrading the old ventilated baghouses, so that the emissions are from a stack or stacks which can be monitored and also will reduce local dust deposition during calm periods.

Stack emissions from liquidator 3 resulting from dross production need additional pollution control in order to reduce the arsenic trioxide emission concentration. It has been proposed that by cooling the gas prior to baghouse filtration, the efficiency of filtration would increase. This cooling could be accomplished by installation of a medium efficiency dry cyclone with modification for air cooling in the exhaust line prior to the baghouse. It may also be necessary to install a second baghouse in series or vent the baghouse to an ESP. The approach here should be step-by-step to minimize unnecessary expenditures. This means that air cooling on a pilot scale should be tested first to determine the potential increase in arsenic removal efficiency of the existing baghouse. Further steps would be dependent on the results of the pilot testing. In addition it would be a good idea to only operate liquidator 3 on windy days to increase dispersion.

A general "tightening-up'' and possibly some modifications are needed for improving shop-floor ambient air quality. This is particularly true for the electric furnaces during charging, the refining and casting area, the hardhead tank, and the area around the AI/As dross storage room and liquidator 3 (particularly during liquidating). An analysis of needs for improvement in hygiene lines, exhaust fans, protective structures, etc., is needed to enable detailed design of cost-effective facilities. A corrosion control analysis should be incorporated in the study in order to prevent further corrosion-related gas line leakage.

The baghouse and hygiene system engineering study and improvement planning is completed and detail design is underway. The construction was expected to begin in the second half of 1986.

Water pollution

The water pollution analysis shows that the only pollutants exceeding MOI effluent standards are from the laboratory and canteen. Because of the small volume of wastewater and the vast dispersion/dilution effect of the tides and currents, it is evident that the effluent does not significantly impact on the local ecology. However, the smelter could easily meet MOI standards by routing the canteen wastewater flow to a septic tank/oil trap system and pumping the laboratory wastewater to the septic tanks system rather than directly discharging to the sea. This will eliminate any direct discharge of undiluted or diluted laboratory wastewater (this is the same disposal method as is commonly used by laboratories in Bangkok).

Noise pollution

The effect of noise pollution has been evaluated by noise level measurements at various locations in-plant and in surrounding communities. Noise pollution was shown not to be an occupational hazard for workers. The normal plant operation does not have any significant effect on sound levels in nearby villages. However, periodically, there are explosions due to slag granulation which are reported to cause nuisance conditions at nearby residences. The smelter has been and is continuously making every possible effort to reduce the frequency of such explosions. The frequency has been reduced from the occurrence of explosion in 18 per cent of tappings in 1983 to 14 per cent in 1985. This results in an average of less than two explosions per week. It is possible that this is the best achievable under present processing circumstances and is thus an unavoidable impact. It is not feasible to shift processing times to ensure that the slag explosions occur during the day. The smelter is continuing to modify its processing to reduce the number of slag explosions. One of the expansion plans is a new cooling water system, for the improvement of the water pressure and water flow rate of the slag granulation system. The high pressure and the high flow rate of granulating water will reduce the chance of slag explosion and therefore reduce the frequency of slag explosion. The installation of the cooling water system is planned within 1986/87 smelter budgets.

Solid wastes

Solid waste pollution control is not a significant factor in the assessment of environmental impacts of the tin smelter because the process solid wastes are either recycled or sold as slag or dust.

Environmental monitoring

The monitoring activities are planned to provide confidence in the continuous improvements in pollution control at the smelter and to ensure that the objectives of environmental protection are met.

The plan includes monitoring of both the natural environment and public and occupational health-related parameters. The monitoring will include systematic measurement of air and wastewater discharges from the smelter as well as special periodic ambient environmental quality measurements.

The implementation of the monitoring plan will serve to provide the following:

(a) establish a database to confirm meeting applicable MOI and National Environment Board criteria and standards;

(b) ensure worker health and safety;

(c) assist in the efficient operation of the smelter by providing feedback on operation/maintenance.

The monitoring programme includes point-source sampling for all significant air and wastewater discharges and ambient air quality sampling for the shopfloor and at the two nearby villages. The monitoring programme also includes continued monitoring of drinking water quality, recording of operational problems of air pollution control facilities, recording of blast occurrences, and continuing safety/health checks. The smelter monitoring programme will commence when appropriate equipment has been identified and obtained. Periodic reports will be issued to the MOI as required.

Concluding remarks

From the overall assessment it can be concluded that, while the tin smelter operations do cause minor effects on the local environment as a result of wastewater and noise, the only significant adverse effects may be caused by air emissions. These problems can be readily overcome so that the overall adverse impacts of the smelter will be minor or possibly insignificant, especially when compared to the major social and economic benefits derived during the past 20 years of operation and which are expected to continue in the future. These benefits are enjoyed by the local population, the Upper South Region, and the nation.


1 Metal Levels Associated with Tin Dredging and Smelting and their Effects upon Intertidal Reef Flats at Ko Phuket, Thailand, Coral Reef, Chapter 1, pp. 131-137, 1982.

2 Environmental Guidelines for Coastal Zone Management in Thailand/Zone of Phuket, H. F. Ludwig/SEATEC, 1976.

3 Inception Report: Environmental Impact Assessment for Thailand Tin Smelter, prepared by SEATEC Consortium, October 1984.

4 First Progress Report, Environmental Impact Assessment for Thailand Tin Smelter, prepared by SEATEC Consortium, March 1985.

5 Manual of NEB Guidelines for Preparation of Environmental Impact Evaluations, National Environmental Board, 1979.

Case study 10.4 Thai National Fertilizer Corporation Project

Source ESCAP: Environment and Development Series, Environmental Impact Assessment, Guidelines for Transport, p. 65.

Notes: This case study can also be used by trainees to develop mitigation plans and post-project monitoring.

Name of project: National Fertilizer Corporation, Eastern Seaboard, Thailand.

Type of environmental analysis: EIS.

Type of project: This project is an ammonia and phosphate fertilizer manufacturing complex. The complex will produce nitrogen-phosphorus (NP) granules, nitrogen-phosphorus-potassium (NPK) granules, urea granules with small amounts of ammonia phosphoric acid, mono-ammonium phosphate (MAP), and di-ammonium phosphate (DAP).

The NFC fertilizer complex will occupy an area of approximately 1.6 km2 on the Gulf of Thailand, and will require an additional area of more than 1 km2, to the east of the main plant location, for phosphogypsum storage. The complex will employ a workforce of approximately 3,000 workers during the construction stage, and approximately 700 during operation.

The complex will produce for sale a total of 670,000 tons per year of NP and NPK granules; 140,000 tons per year of urea granules; and smaller amounts of ammonia phosphoric acid, MAP, and DAP. Most of the complex output will be shipped to domestic dealers for further distribution. This quantity of fertilizer product represents a sizeable percentage of Thailand's fertilizer needs.

The complex was scheduled to begin operation in late 1987, based on the initiation of construction in early 1985.

Solid raw materials required by the complex, with the exception of filler, will be brought to the complex by ship. Products will be distributed by barge and by truck, and/or by rail. Water will be supplied from Dok Krai Reservoir, which has ample capacity to satisfy project needs. Power will be available from the new facilities of the Provincial Electricity Authority (PEA) and Electricity Generating Authority of Thailand (EGAT) which are being developed to serve the growing needs of the Eastern Seaboard Area. These and other requirements of the complex, such as transportation, port facilities, and housing for workers, have been included as part of the overall development plan for the Map Ta Pud Industrial Estate.

The processes and operations that will be used at the complex are similar to those that are presently in use at many other fertilizer plants worldwide. No new or experimental technology is utilized in the complex. The complex is planned to be a modern, environmentally sound facility that benefits from worldwide experience.

Project location

The National Fertilizer Corporation will be located on the Gulf of Thailand at the Map Ta Phut Industrial Estate in Rayong Province.

Reports on pertinent studies

See References 1 and 4, pages 316 and 317.

Environmental study area

The study area described by the EIS will include an area within a 20 km radius from the project site. Because most of the impacts caused by construction and operation of the complex will occur in the project area, this will be the only area described in depth.

EIA team

The EIS has been basically prepared for MFC by its consultants, namely TESCO (a Thai environmental consultant), Foster Wheeler International Corporation, the project management consultant (PMC), and Synco (an environmental consultant). This was a one-year study involving approximately 30 professionals with specialist inputs on physical resources, ecological resources, human use values, quality-of-life values, and project management.

EIA budget adequacy

Before the EIA process is started, one needs to ensure that adequate budget is available to collect data, analyse data available, carry out necessary research investigations, and develop any appropriate models.


The EIS document has been prepared in accordance with information included in the manual of NEB Guidelines for preparation of environmental impact evaluations as well as the specific guidelines contained in the terms of reference (TORs) developed by NEB for the EIS on the particular project. Work in preparing the EIS has considered all studies and potential impacts identified in TORs.

The methodology for making an EIS is essentially that prepared by the Battelle Institute/United States Army Corps of Engineers for water resources development projects. Here the environmental impacts are studied in four categories: (a) physical resources, (b) ecological resources, (c) human use values, and (d) quality-of-life values.

Field studies were performed on each of these topics, and existing data were used as appropriate.

Existing environmental conditions


At present, the part of Rayong Province where the complex will be located is largely rural. Cassava cultivation dominates the area, with sugarcane, fruit trees, pineapples, coconuts, and rice also occurring frequently. Rubber is also increasing as a local crop. In the immediate vicinity of the site are several small villages, including Ban Ao Pradu, Ban Nong Faeb, Ban Nong Ta Tik, and Ban Ta Kuon. At a distance of about 5 km is the municipality of Map Ta Phut, which has a population of about 7,000. More sizeable nearby population centres include Rayong, which is about 15 km to the east, and Sattahip, which is about twice as far to the west.

Cassava processing dominates the industry of the area, with cassava pellet and cassava flour manufacturing plants the most prevalent industry by far. There are nine such plants within only a few kilometers of the plant site. A second significant industry is pineapple canning. However, the first stages of the planned industrialization of the area are already evident, namely construction of the PTT Gas Separation Plant. Also, a plastic granules facility has been built a few kilometers to the east of the plant site, in Rayong.

Since the plant site is a seacoast area, two activities usually associated with the ocean are also found, namely fishing and recreation. A small resort, Haad Sai Thong, is located at Ban Ta Kuon, about 3 km east of the plant site and 1 km south of the gypsum stack area. The resort is located near the mouth of Khlong Huai Yai, which is a stream located to the west of the gypsum stack. Some recreational house plots belonging to individuals are also found in the area.

The fishing industry is less significant to the area than agriculture, and fishing activity centres around the mouth of Khlong Huai Yai. The area is not considered a prime fishery area.

Topographically, the project area is relatively flat. The plant site is at an elevation of 5 to 10 m MSL. The land rises gradually towards the inland areas, with isolated hills at distances of 10 km or more from the plant site. Drainage is good, flowing primarily southward to the sea. Flooding is not a significant problem.

The area is not seismically active and is far from existing centres of seismic activity.

Several different types of soils are found in the area, and these are identified on a soils map presented in the report. In general, the soils tend to be sandy, well-drained, and low in nutrients.

Although agriculture is important in the study area, the methods used are not entirely efficient or modern. Fertilizer is applied to crops in many cases, but in amounts that are generally less than recommended. Therefore, especially in cassava areas, nutrients in the soil are gradually being depleted. Farm machinery is used in some cases, water buffalo and cattle in others. Water shortages have been found to be a problem, which is being addressed in part by a government programme to encourage the growing of rubber, which has roots deep enough to reach groundwater, rather than cassava.

Water and power supply to the project area have been incorporated in plans for construction of reservoirs and electrical substations to serve the area. At present, the Dok Krai reservoir provides water for irrigation. It is planned that this water will be transferred to the industrial estate. However, by the time this occurs, another reservoir, Nong Pla Lai, will have been constructed to supply irrigation water. Electrical power substations are now under construction in the region to increase the availability of power for industry.

Transportation facilities of many kinds to serve future needs of the area have been planned by the responsible agencies and authorities. These facilities are at various stages of early development and include highway and road networks, a railway line, and an industrial port facility for ocean-going vessels.

Existing environmental conditions

Air quality in the vicinity of the plant site has been sampled at two locations, and has been found to be generally well within air quality standards. Particulates were found to be present at levels of 81 to 92 mg/m3. High levels of total hydrocarbons (1,350 to 2,600 mg/m3) were noted, but since the methane portion of the measurement was not accounted for, the values cannot be compared to standards.

The two air quality sampling stations were located at Map Ta Phut and Huai Pong, near centres of population and of industrial development. Thus, it can be expected that air quality elsewhere in the region is better than at the two locations studied.

In the immediate vicinity of the plant site, there are several perennial streams but no rivers. The streams, Khlong Huai Yai and Khlong Nam Hoo, join and flow to the sea at Ban Ta Kuan/Sai Thong. These streams also border the gypsum stack location on the east and the west, respectively.

Water samplings to date have found the water quality to be rather poor and affected by upstream discharges from industry and communities as well as by salt water intrusion. The water level was very low in both streams, and in the April sampling, Khlong Nam Hoo was found to be stagnant, due to the irrigation dam being closed. Turbidity was high, as were total solids and total suspended solids. COD was high, especially in the upper location on Nam Hoo. The influence of salt water intrusion could be seen at the lower location on Nam Hoo, since high levels of total solids, sulphate, and salinity were found.

Sea water quality is found to be affected by contaminants in fresh water discharges, with near-shore water in a state of eutrophication because of waste organic matter brought in by the streams.

Sub-surface strata in the project area generally consist of sand near the surface, sandy clay below, grading into a clay layer with very little sand at even greater depths. A bedrock of granite underlies the area. The depths and thicknesses of the individual layers vary spatially, with the region nearest the shore having the most extensive sand layer. Inland areas, namely the gypsum stack site, have more extensive clay layers.

Groundwater is high in iron, manganese, and turbidity. Low pH was also found in some cases.

Existing pollution in the area is caused primarily by the human population and by the cassava processing industry. Wastewater, consisting both of sanitary waste from residences and of effluent from tapioca plants, contributes high loadings of BOD to the local streams. Solid waste, that is rubbish and garbage, is burned, land-filled, or dumped into the sea.

Existing air emissions from industrial sources consist primarily of SOx and particulates, and are generated by tapioca plants and other industries in the area.

In the Rayong Province, public health is generally not good, because of the combined problems of poor sanitation, lack of potable water, presence of malarial mosquitoes, and insufficient health care professionals. Malaria, although declining, is still the most common "notifiable disease'', and of these diseases, causes the greatest number of deaths.

At present, people living in and around the plant site are aware that the area will be expropriated for the industrial estate. However, those living in and around the gypsum stack area are not so aware, although rumours exist. People living in the study area generally perceive the project as providing socio-economic benefits, including job opportunities and future development, although they also believe there will be increased pollution as a result.

Environmental base map

There is not any specified EBM in the report. However, a location map shows the waterways, transportation routes, pipelines, etc., in the vicinity.

Environmental effects from the project

Adverse effects on physical resources

Potential impacts to surface water quality during construction could arise from dust emissions (from vehicles and disturbance of soil cover), high suspended solids (from storm water run-off), and sanitary waste (from construction personnel).

The discharge of wastewater from the fertilizer complex, under all-flow conditions, will increase the concentration of sea water contaminants in the area near the discharge point. Sea water within a short distance from the discharge point will be hazardous to marine life. Under misoperation conditions, sea water pH will be affected in the initial dilution zone and high concentrations of fluoride and phosphate will be released into the receiving water.

The turbidity and some dissolved minerals will be increased in the groundwater. According to the hydro-geological characteristics of the project area, the major problem in the gypsum stack area is the potential contamination of shallow unconfined groundwater by leachate from standing water used in gypsum disposal.

The topography will be affected temporarily during the construction phase.

Fluoride and phosphorus pentoxide emissions from the NFC plant will lead to depositions in the soil surrounding the plant site and gypsum stack.

Construction and operation activities will generate localized sources of high noise level. During operation of the NFC complex, road trucks will be used to transport product and some raw materials. It is estimated that truck traffic volume will be 20 trucks per hour based on 6 days per week. Noise level from road trucks ranges from 82 to 92 dBA at a distance of 15 meters. Only the Haad Sai Thong recreation resort will be significantly affected by these transportation activities.

Construction activities will create additional emission sources typically associated with large construction projects. These additional sources include air emissions from construction vehicles and equipment, fugitive particulate emission from the disturbance of soil cover, water quality impacts from surface run-off, and potential impacts from the sanitary waste of construction workers.

Adverse effects on ecological resources

Construction activities at the phosphogypsum disposal area will impact fresh water ecology in the two streams since the area is very close to the streams. There will be an increase in total dissolved solids and turbidity of the water from erosion and run-off. Sedimentation from erosion and surface run-off will also affect living conditions such as respiratory processes and feeding habits of benthic organisms and some fishes. The dominant benthic organism in Khlong Huai Yai was Chironomus sp., which will be affected by sedimentation.

High concentrations of some chemicals in the NFC plant wastewater will be a hazard to marine organisms within 3-5 m from the discharge point along the plume trajectory. Any possible adverse impact from the fluoride will be limited to a 5 m radius around the diffuser and then it will only affect very sensitive species (Perna Perna).

Adverse effects on human use values

The NFC will change the existing land use pattern in the project area from agricultural areas, villages, etc., to the fertilizer plant and gypsum stack. Houses and the crops in the plant site will be removed and the land owners will have to find a new place for settlement.

Two unpaved roads located in the plant site area and used by local commuters will be eliminated by plant construction. Traffic volumes will generally increase near the project area.

Fluoride emissions from the operation of the NFC plant will cause some localized impacts on existing agricultural vegetation. An area of approximately 140 ha, generally north of the gypsum stack, is exposed to annual average fluoride concentrations above 0.25 μm/m3. Plants sensitive to fluoride may be affected in this area. Thus the unknown susceptibility of the majority of crops (cassava, coconut, paddy rice, and rubber) needs a threshold examination.

Examination of the monthly ground level fluoride air concentrations reveals areas that receive a two-month average above 0.33 μg/m3. Forage materiais are subject to fluoride accumulation and if it exceeds 40 ppm (less than 0.33 μg/m3), cattle may suffer fluorosis. But the areas of potential forage contamination are not in the pasture, and constitute a maximum of 1.4 per cent of the study area. However, there is an increased percentage of susceptibility.

Contamination of the streams with increased phosphates and ammonia will increase the aquatic plant biomass. This will change the ecosystem and thus affect fisheries.

A small number of swimming crab fishermen may have to move from the fishing ground adjacent to the project site to fish in other areas. Some adverse effect of the discharge (fluoride and phosphate) on the larval stage of fishes and invertebrates may be expected.

Construction of the NFC complex will require resettlement of villagers who are presently living on portions of land to be devoted to the project.

Some impact is anticipated at the black sand beach mine at Nong Baeb. It will depend upon conflict resolution between the mining company and the government during expropriation for the Map Ta Pud Heavy Industrial Estate project development.

Adverse effects on quality-of-life values

Impacts will occur from plant construction and operation due to the number of workers moving into the area. Plant operation will create an area around the gypsum stack having impacts from fluoride emissions. The majority of the villagers are aware of possible water and air pollution. During certain operations, ambient concentrations of contaminants can be expected to increase. An ammonia spill would have a significant impact on public health.

Measures for offsetting adverse effects

The mitigating measures of the project plan that will offset the potential impacts are described as follows.

(a) Siting of the complex in an area where many of the existing environmental resources/values are not of prime importance. The project site: (1) does not contain any valuable ecological resources (either terrestrial or aquatic), (2) does not contain any items of archaeological significance or historical importance, (3) is not subject to floods or seismic disturbances, (4) is not heavily populated, (5) is not the location of significant mineral resources or mining activities, and (6) is not a prime area for tourism, recreation, or aesthetic pursuits. The project will also not compete with local industry for raw materials, or workers with similar skills.

(b) Procedures in the construction period will involve: preferential use of local labour to minimize the number of workers who migrate to the area; establishment of construction camps by subcontractors for migrant workers; use of dust suppressant spraying to minimize fugitive dust during construction activities; use of temporary dams to control erosion and promote settling of particles from stormwater run-off to prevent damage to surface waters (fresh and nearshore) and aquatic ecosystems; provision of sanitary waste facilities for workers; and cooperation with local and provincial public health authorities.

(c) Use of air emission control equipment that limits emissions of pollutants, including SOx, NOx, hydrocarbons, acid, mist, ammonia, carbon monoxide, and volatile organic compounds, to levels that result in ambient concentrations well below applicable air quality standards. Emissions from the plant will also not create any harmful synergistic effects with each other (i.e., ammonia with CO) or with other existing emission sources in the area. Deposition rates are low enough that they will not adversely affect soils.

(d) Siting of the gypsum stack area over a thick layer of naturally occurring, low permeability clay to serve as a liner that will prevent seepage of cooling pond water from reaching groundwater or surface water.

(e) Constructing very low permeability dikes around the gypsum stack down to the underlying clay layer to provide safe lateral containment for the gypsum pond water and to restrict the potential impact on neighbouring groundwater to insignificant levels. Analyses show that conservatively projected seepage rates are so slow that the time required for contaminants to escape the gypsum stack area exceeds the life of the plant by more than a factor of four.

Use of on-site wastewater treatment to treat effluent from the complex, followed by use of a well-designed, submerged diffuser 2,000 m from shore to discharge the effluent to the ocean at a depth of 4 m. Analysis shows that the sea water quality beyond about 10 m from the discharge point will be only minimally altered and that no significant impacts will occur on marine ecosystems or fisheries.

(g) Plant operational procedures that utilize evaporation from the gypsum cooling pond to minimize wastewater discharge from this source, restricting it only to part of the rainy season (about 3 months per year).

(h) Stacking of phosphogypsum in the gypsum stack area using well-established techniques that involve double-diking to minimize the chance of leakage or spillage of slurry water from this area.

(i) Application of noise criteria that will meet United States Occupational Safety and Hygiene Association (OSHA) standards for occupational noise within the plant boundary. Any equipment not meeting noise control standards will be subject to attenuation, and ear protection equipment will be provided if necessary. Attenuation of plant noise by distance beyond the boundary will reduce noise impacts on human receptors in the area to insignificant levels.

(j) Commitment by the project to conduct environmental monitoring activities during construction and operation of the complex so as to verify the protection of the health and welfare of workers, nearby population, and the surrounding environment. Monitoring activities will be performed at locations both within the complex and around it. Significant sources of emissions and effluents have been identified and will be monitored. The monitoring programme will cover: (a) sources within the plant, (b) air quality and meteorology, (c) surface water quality, (d) sea water quality, and (e) groundwater quality. Selected ecological studies may also be made. The early results obtained will be used to modify details of the monitoring programme as necessary. To the extent desirable, the monitoring programme will use the same sampling stations and parameter lists as in the baseline programme. The monitoring results will be compiled and reported periodically to the appropriate authorities.

(k) Commitment by the project to perform an occupational health and safety monitoring programme covering employees of the complex, so that any concerns can be identified, addressed, and countered by the proper remedial action.

(l) Project plans to investigate alternative commercial uses for phosphogypsum to eliminate the need to stack it over the life of the plant. These commercial uses could include: (a) being a raw material for manufacture of plasterboard or cement, or (b) application as a soil conditioner (possibly with lime) to supply calcium and sulphur to soils. These kinds of uses for phosphogypsum are being demonstrated in Japan and the United States.

In addition to the potential impacts summarized above that are mitigated by the project design, by regional circumstances, or by the location of the site, several other potential adverse impacts were identified that will be mitigated by plans or activities to be developed and undertaken by the project. The topics involved in these impacts are: (a) fluoride emissions from the gypsum stack and resulting fluoride impacts on nearby agriculture, livestock, flora, fauna, and people; (b) relocation of villagers living in the gypsum stack area; (c) socio-economic and public health issues associated with low probability "worst case'' emissions or discharges from the complex; and (d) cooperation with local, provincial, and governmental authorities on infrastructure and facilities planning so that growth in the area can be adequately managed.

Environmental monitoring

The project will have an environmental monitoring programme during both construction and operational phases to provide continuing assurance that the planned environmental protection measures are working adequately.

During construction, environmental monitoring will be conducted on: (i) particulate emissions from traffic, earth moving, and debris, and surface water quality effects associated with construction area run-off at both the plant site and gypsum stack area. During operation, major sources of air emissions and wastewater discharge will be monitored at the plant. In addition, ambient air quality surrounding the plant will be monitored, along with meteorological conditions. Water quality monitoring will include both surface and groundwater. Surface water sampling stations on inland streams and in the ocean will be the same as those used in the baseline study. Groundwater monitoring will occur both up-gradient and down-gradient from the gypsum stack in shallow wells. Occupational health and safety of workers at the plant will be monitored on a continuing basis.

Concluding remarks

The EIS study conducted for the ammonia and phosphate fertilizer complex was conducted in accordance with the study plan developed with and approved by the National Environment Board (NEB) of Thailand. The EIS report produced as a result of the study is compatible with both the NEB's guidelines for the preparation of the environmental impact evaluation and the terms of reference prepared by NEB for the NFC project.

Potential environmental impacts associated with constructing and operating the project were evaluated for a total of 28 separate topic areas in 4 major subject categories (physical resources, ecological resources, human use values, and quality-of-life values). This evaluation represented a comprehensive investigation of how the project might affect the environment based on present plans for its construction and operation.

In the analysis, emphasis was placed on evaluating those impacts affecting the sensitive receptors that were identified in the project area. Both routine and non-routine operating conditions for the complex were considered, including several low probability "worst-case'' conditions. For some topic areas, no sensitive receptors, issues, or impacts were identified. These areas received correspondingly less emphasis.

Because of the commitment by NFC to design the plant using modern, environmentally sound control technology and to take advantage of favourable existing conditions in locating plant facilities and defining plant operating procedures, the EIA revealed that many potential impacts had already been effectively mitigated.

For example, locating the plant in a major new industrial estate (i.e., at Map Ta Pud) that has been the subject of extensive planning and analysis by several private and governmental bodies, allows NFC to benefit from the planned infrastructure development already completed. Utilization of land for the plant site that is within the territory expropriated by IEAT simplifies many land use and socio-economic impact questions.

The complex will also benefit from development projects planned in the Map Ta Pud area for transportation (highways, railway line, and deep-water port), water supply (from Dok Krai Reservoir), power supply (by PEA and EGAT), natural gas supply (PTT), and housing (new town - Ban Chang). The effect of this previous planning is to reduce impacts in these particular topic areas to levels of no consequence. NFC will coordinate with these other projects to assure their timely development and compatible schedule.

The overall conclusion is that by using the planned mitigation and control measures, the NFC project can be constructed and operated without significant impact on the environment.


1 Preliminary Report of EIS Study of National Fertilizer Complex, July 1984.

2 C. Tharnboopha and N. Lulitanon, Ecology of the Inner Gulf of Thailand, Marine Fisheries Laboratory Technical Paper No. 4/1977 (in Thai).

3 C. Tharnboopha, Water Quality off the East Coast of the Gulf of Thailand, Marine Fisheries Laboratory Technical Paper No. 10/1979, 1980 (in Thai).

4 Study of Pollution Control Measures and Impacts of the Development of Chemical Fertilizer Complex and Integrated Steel Industry, Mahidol University, Volume IV, Environmental Status and Impacts on the Development of Chemical Fertiliser Complex and Steel Industry on the Sea-Coast in the Eastern Region of Thailand, 1983.

5 The Directory of Industrial Factories in Changwat Rayong, Rayong Provincial Industry Office, Ministry of Industry, 1982.

6 S. Khetsamut, et al., Benthic Animals off the East Coast of the Gulf of Thailand, Marine Fisheries Laboratory Technical Paper No. 11/1979, Dept. of Fisheries, 1979 (in Thai).

7 Report on Initial Evaluation on Major Industry on the Eastern Seaboard, Environmental Working Group, National Environment Board, Volume 1, March 1981.

8 Development Document for Effluent Limitations Guidelines and New Source Performance Standards for the Basic Fertilizer Manufacturing Point Source Category, United States EPA, March 1974.

9 Guide to Pollution Control in Fertiliser Plants, United Nations Industrial Development Organization, Monograph # 9.

Case study 10.5 Map Ta Phut Port Project

Note: This case study can be used to generate an impact network diagram.

Name of the project: Environmental impact statement of Map Ta Phut Port Project, by Industrial Estate Authority of Thailand, August 1985.

Type of environmental analysis: EIS.

Type of project: This is the development of a commercial port or multi-user zone. Within this area, the following will be established: a port operations centre, bulk commodity storage areas and berths, general cargo storage facilities, and bulk liquid berths. Marginal reclamation along the shoreline will also be incorporated.

The site of the Map Ta Phut port was fixed during the earlier feasibility study (JICA 1983) relating to the establishment of a major heavy industry and residential zone in Rayong province. Concerning berth requirements, construction of Map Ta Phut port is intended to proceed in phases to provide facilities supporting progressive growth in industries adjacent to the site. Thus three development stages are considered.

(a) Short-term development: required before 1992 for loading raw and finished products of NFC, MPC, etc.

(b) Interim operations: specialized facilities for handling hazardous flammable liquids.

(c) Interim operations: specialized facilities for handling hazardous flammable liquids.

Table 10.4 Work force - port personnel



General cargo berth



Liquids berth






Customs & immigration



Port administration



IEAT personnel



Harbour operation - marine



Harbour operations - engineering & administration



Other facilities - gatehouse, weighbridge, fire, medical, canteen, etc.





The port will have all the basic facilities as following: (1) harbour craft requirements - tugs, pilot launches, work boats, buoy maintenance; (2) road and rail; (3) work force (see Table 10.4); (4) water supply, drainage, and wastewater collection and treatment; (5) solid waste management; (6) emergency services; (7) power supply; (8) port traffic; and (9) cargo handling and storage.

Project location

The Map Ta Phut port project is located in Rayong province in the eastern seaboard area and the site is exposed to the Gulf of Thailand.

Reports on pertinent studies

See References 2 and 3, page 329.

Environmental study area

The port will occupy approximately 2 to 8 km of shoreline and an offshore area within the break of about 4.75 km. The dredged shipping channel will extend to approximately 4 to 5 km from shore. For the purposes of the EIS the port has been defined to include all offshore works, the commercial port area, and the berths and loading/unloading areas for specific uses (tapioca, fertilizer, raw materials, and products).

EIA team

Not provided with the report.

EIA budget adequacy

Not provided with the report.


The methodology basically follows the procedure laid down by the National Environment Board. First of all an initial environmental examination was made in January 1985, for which comments were received from IEAT and the National Environment Board, after which this EIS report was made. The EIS follows an "item to item'' impact description.

Existing environmental conditions

See the relevant section from Case Study 10.4, pages 307-310.

Environmental effects from the project

The network of potential impacts of the proposed port is divided into main parts: (i) the construction phase and (ii) the operational phase.

Adverse impacts: aquatic

Dredging and reclamation will result in formation of plumes of suspended sediment around the dredgers, reclamation outfalls, and dumping ground. The coastal waters at Map Ta Phut are at present unpolluted and have low levels of suspended sediments.

Small areas (at most 3.5 km2 mostly about 0.5 km2) will be affected sufficiently by increased turbidity and deposited sediments to affect marine biota and productivity, in some cases causing total loss of photosynthetic activity. This will necessarily have further implications in the food chain of the coastal environment. The impact in the context of biotic and fishery resources of the Eastern Seaboard is not considered to be significant, although local fishermen will be forced to fish elsewhere. There is little inshore fishing activity at Map Ta Phut compared with elsewhere along the coast and the coastal waters are not considered to be a significant spawning or nursery areas compared with waters further to the east.

Disturbed sediments will have a more significant impact on recreational resources at the Sai Thong beach resort just to the east of the port site, reducing the quality of inshore waters for contact and non-contact recreation during the construction period.

Disturbed sediments will also damage the remaining corals on the islands of Ko Saket, but these have been evaluated as low in significance as an ecological or touristic resource in comparison with other colonies occurring along the Rayong coastline.

The sediments that will be released have been tested to determine their polluting potential. It is concluded that the sediments are unpolluted and that the potential for uptake of dissolved oxygen or release of nutrients affecting biological productivity is negligible.

Maintenance dredging during operations will not have significant impacts on the marine environment.

Other sources of water pollution in the area at present are tapioca-processing plants and communities. These result in poor quality in streams flowing through the area (high BOD and low dissolved oxygen) but there is no evidence of their having adverse effects on coastal water quality. Monitoring of coastal waters and sediments indicate that the marine environment is largely unaffected by land-based sources of pollution.

Sources of water pollution include: run-off during construction and quarrying; sanitary wastewater during construction and operation, including shipboard wastes; and oily wastewater and tank washings.

The impacts from run-off, sanitary, and oily wastewater will not be significant in relation to other sources which will occur as the area develops, provided appropriate measures are taken to collect, treat, and dispose of wastewater.

Quarrying and transport of quarried materials also have the potential for water pollution by dust, but this is not expected to be significant at any of the proposed sites.

Construction of the port could affect dispersion of effluents from the proposed outfall from the National Fertilizer Corporation's plant on the industrial estate. This impact has been evaluated and the impact is not considered to be significant.

Adverse impacts: atmospheric

Sources of air emissions during construction will include: dust from traffic, site clearing, and construction activity; emissions from vehicles bringing materials to the site and from construction equipment; emissions from burning of waste materials; and dust from quarrying.

These emissions are expected to result in degradation of air quality, primarily in the working environment affecting construction employees. Dust and other emissions from on-site are unlikely to spread sufficiently to affect homes and other properties around the site.

Dust and emissions from vehicles carrying materials, particularly quarried rock and aggregate to and from the site, are expected to generate dust nuisance in communities along their routes. This will only be significant if the Khao Bandai Krit East site is selected as the routes from other sites do not pass close to communities.

Dust from quarrying itself will affect communities and farm fields in the immediate vicinity of sites. It will be significant at Khao Bandai Krit East and Khao Noen Krapok where it will affect cassava fields and orchards adjacent to the quarry sites. There are no houses within 500 m of any sites, except for worker housing at Khao Chi Chan. Dust will be generated within the quarry working areas and measures will need to be taken to protect workers.

The existing air quality at the site is high and there are no major sources of air emissions. Development of the industrial estate will inevitably change this situation. Emissions and resulting air quality resulting from ships using the port and other port activities have been predicted. Emissions from the port are unlikely to cause significant deterioration in air quality compared with NEB standards.

Dusty cargoes present risks to workers on site and to people and property from dust nuisance generated during handling and dust explosion hazards.

Handling tapioca is likely to be the greatest source of nuisance in surrounding communities, although there may be some visual impact, as is evidenced from tapioca-handling facilities elsewhere on the Inner Gulf.

Adverse impacts: noise and vibration

The noise environment at Map Ta Phut is typical of a quiet rural area. There are no significant sources of noise in the area at present. Sources of noise during construction and operation will include: construction equipment and activity; vehicles; cargo handling equipment; and ship and port PA systems and sirens.

The working environment will be subject to significant noise levels and measures will be required to ensure that Labour Department standards for occupational noise levels are met.

After development of the industrial estate, the numbers of people living close enough to the site to be affected by noise from port operations will be very small and this impact is not considered to be significant.

Adverse impacts: land and other resources

The coastal strip which will be affected by development of the port and the associated industrial estate is low lying. About 40 per cent of the area is used for farming - growing orchard fruits, coconut, cassava, and other crops. There are 5 houses and several groups of fisherman's huts along the shoreline. There is also a picnic area. Two houses and one group of fishing huts are actually within the area to be occupied by the port.

Outside the boundaries there are numerous shelters and huts, a private resort area, and 1.5 km to the east a small beach resort (Sai Thong) with a capacity of about 150 persons.

All properties and land uses within the site boundaries will be lost, but the impact of the port in isolation from that of the industrial estate will be compensated. Fishermen using the shoreline are mostly not land owners and will not therefore be entitled to compensation. Many of them have moved to the area within recent years to avoid overcrowding elsewhere.

Construction of the port will change patterns of littoral sediment drift causing build up to the west of the port and erosion to the east. This would have a significant impact on the beach at Sai Thong unless provisions can be made to replace the eroded material.

The port development will place only a small demand on water and power supplies and the transportation network compared with the industrial estate. Its impact is not therefore considered to be significant.

Black sand mining for extraction of tin has been carried out on a small scale along the foreshore at Map Ta Phut. Access to the resource will necessarily be foreclosed by port construction.

The value of these resources has never been estimated but the fact that no mining has been undertaken in recent years suggests that the resource is not of major commercial significance.

The potential impact on Sai Thong beach resort was noted above. The island of Ko Samet is also being developed for tourism. The port is unlikely to reduce the level of use of these facilities, it may in fact increase it; but it is likely to change the visitor population from non-local visitors to visitors associated with the port and industrial estate workforce and supporting populations. The area is not considered to be of regional or national significance for tourism.

Adverse impacts: visual impacts

The port and industrial estate development will have a major impact on the immediate visual environment, replacing an undeveloped coastline with large industrial buildings, cranes, warehouses, and other structures.

The main impact will be on those people living adjacent to the site or using the island of Ko Samet for recreation. The horizon is close owing to the low-lying wooded terrain and the port is not expected to be visible from the resort buildings at Sai Thong but the eastern reclamation will be visible from the beach. Until such time as major structures are built on the eastern reclamation, the port is unlikely to be obtrusive from the beach. Ships entering and leaving the port may be considered as a positive attraction.

People using Ko Samet will have a clearer view of the commercial port area and the industrial estate. The impact will therefore be much greater.

Adverse impacts: solid waste disposal

Wastes will be generated during construction, by the construction workforce, by the permanent workforce, by cargo handling operations, and from ships discharging in port.

The daily waste generation during operation is estimated to be about 3 tonnes per day. Waste generation during construction and operation is unlikely to cause adverse environmental impacts provided appropriate measures are taken for collection, treatment, and disposal.

Adverse impacts: accidental

Accidents may be caused by incidents on-board ship, fire, explosion, occupational accidents, collision between vessels, and grounding, on the shore or on the gas pipeline to the west of the port.

These accidents may result in loss of life or injury, damage to property, and pollution by spills. The risk has been quantitatively assessed on the basis of presently available data; however, it is our view that the risks are such as to require strict control over shipping movements.

Risks from explosions caused by dusty materials are discussed above (Adverse impacts: atmospheric-page 320). Other risks to people and property may arise from handling of dangerous cargoes: vinyl chloride monomer, hydrocarbon gases, chlorinated hydrocarbons, caustic soda. Details of hazardous cargoes to be handled at the port are not available, but if such cargoes are to be transhipped, the appropriate preventive measures and emergency provisions should be established.

Adverse impacts: socio-economic and public health impact

Development of the port and industrial estate will have a very major impact on local socio-economic conditions, changing the area from a rural area with low population density and relatively low income, to an industrialized area with a large new population and opportunities for significant creation of wealth.

The impact of the port alone is unlikely to be significant in isolation from the complete development, as the port workforce will be 900-1,000 compared with an estimated total of over 15,000 for the industrial estate. This could lead to an induced population increase of as much as 70,000 by the time the estate is fully developed. A new town will be built to house the majority of this population and a separate EIS is being prepared for this development.

Two houses and a group of fishing huts lie within the port boundary and will be demolished in the early stage of construction. Several other properties lie within the industrial estate boundary. At present it seems that the affected families and fishermen are not aware of the proposed development and are making no plans to relocate.

The main employment sectors that will be affected by the port development are inshore fishing and tourism. The number of families relying on fishing for part or all of their income is believed to be about 20. 70 crab and shrimp nets are in operation in waters adjacent to the port and there are several squid fishing boats. Incomes of these families vary from season to season very substantially, but are generally low compared with industrial and agricultural workers.

It is expected that some fishermen will take up employment associated with the port; others will move elsewhere and provisions may have to be made to facilitate this to avoid family and social problems.

Employment in tourism, at the Sai Thong beach resort and Ko Saket, is expected to increase as a result of the port development. There will also be substantial increases in employment opportunities in sectors servicing the large new population.

It is likely that unless strict controls are exercised, illegal development will occur around the plot boundary, with consequent problems of water supply sanitation, public health, waste disposal, and unsightly development.

Public health impacts may include an increase in communicable disease incidence caused by the influx of workers and foreign sailors and disposal of shipboard waste; an increase in disease through poor sanitation in camps, new housing areas, and squatter settlements; and stress on available medical facilities caused by a large increase in population.

Measures for offsetting adverse effects

Aquatic impacts

The following mitigation measures have been proposed for dredging and reclamation. Construction of the western breakwater and silt basin should be a priority to minimize sediment release from the reclamation. Reclamation of the eastern area should be as far as practicable, awaiting construction of the eastern revetment, to minimize impacts on the Sai Thong beach resort. The eastern reclamation should be drained into the port, not outside the eastern revetment, to minimize impacts at Sai Thong. Best practicable technology and operating methods should be used to minimize sediment release from dredging and barge loading. All operations should be properly supervised and a regular programme of equipment maintenance carried out. Overspill from loading barges should be kept to a minimum, consistent with achieving an economically viable load, while loading barges should be regularly checked and maintained to prevent leakage from bottom seals. Spoil should be dumped only within specified boundaries and a pattern of dumping should be adopted to minimize repeated dumping in exactly the same spot. These same general conditions should also apply to maintenance dredging where relevant. It is not considered that further physical measures to control fine sediment release are necessary.

The following monitoring measures are proposed. Bottom conditions should be inspected and recorded by divers at intervals before and during construction and operation and if possible a photographic record kept. Turbidity in waters at Sai Thong should be measured at monthly intervals over the construction period to monitor aesthetic and water quality impact on recreation. Dissolved oxygen, ammoniacal nitrogen, and other nutrients should be measured at intervals during construction to determine whether water quality changes have occurred as a result of dredging. Records should be kept of any evidence of algal blooms and of the conditions under which they have occurred. If it can be arranged, a serial photographic record of sediment plumes around dredgers, barges, reclamation drains, and dumping sites should be made, principally for reference in assessment of similar developments in the future.

Mitigation measures for other impacts on water quality. Temporary bunds should be constructed to contain surface run-off from the land sites. Collected run-off should be passed through retention ponds to collect suspended solids, before discharge. A treatment system should be provided at the construction camp. This should be either a package plant or septic tank. Consideration should be given to two possible alternatives for treatment of sanitary wastewater during port operations: either an anaerobic pond followed by facultative and polishing ponds discharging to a near-shore outfall; or an anaerobic pond discharging to an offshore outfall. A conventional activated sludge sewage treatment plant is not considered to be appropriate for port operations owing to fluctuations in the volume and quality of loads. Sanitary effluents should not be discharged into the harbour itself. There may be some merit in providing a combined outfall with NFC, provided construction can be scheduled appropriately for both developments and operational arrangements organized. All sanitary provisions should be in accordance with the Memorandum on Guidelines for Incorporating Sanitation Parameters into Planning Design of Ports and Harbours in Developing Countries including Thailand. Oily wastewater (from fuel storage tanks, maintenance shops, ship bilgewaters, tank washings) and run-off from dirty areas of the port (vehicle marshalling, parking, and fuel storage areas) should all be collected and passed to an oil-water separator before discharge. Oily run-off may be returned to the stormwater system after treatment. Reception facilities for oily wastes from ships should be provided and their use enforced by monitoring and penalties for oily discharges in or approaching the port.

Regular monitoring of water quality should be carried out within the port and in adjacent waters during operation, to identify adverse environmental changes.

Atmospheric impacts

Mitigation for general emissions. Good housekeeping practices should be adopted to control dust from construction operations, quarrying, and transport of quarried materials. These may include periodic water spraying dusty areas and shielding of dusty areas, maintenance of road surfaces, ventilation of enclosed areas, cleaning of equipment and vehicles as well as adoption of proper operating methods. Unpaved access roads which may lead to dust problems in communities should be paved. Burning of waste materials should be avoided.

Occasional monitoring of air quality should be carried out by the appropriate government agencies in Map Ta Phut village, Sai Thong, and the new town, and in the working environment of the port.

General housekeeping measures to control dust emissions as described above, should be adopted when handling dusty cargoes. Recommendations on handling dusty cargoes to minimize dust nuisance in the occupational and external environment and to reduce the risk of explosion, should be adopted, and laid down by the Port Authority as conditions for private operators. Occasional monitoring should be carried out by the Port Authority to determine dust levels in the occupational environment within the port.


Noise specifications for construction equipment should be laid down in contracts for construction work in accordance with Labour Department standards for the occupational environment.

Occasional measurements of sound levels in the occupational and external environment should be made to monitor noise. Records of complaints should be kept.

Land and other resources

Mitigation measures. Compensation will be provided for land owners as required by existing schemes. Several fishermen who have no legal status will be displaced and consideration may be given to giving them financial and other assistance in finding alternative employment or alternative locations at which to keep their boats and equipment. Strict boundary regulations should be enforced to prevent overspill of activities beyond the port and industrial estate and to prevent illegal squatter settlement. The boundary should be securely fenced and regularly inspected. A programme of excavation of sand accumulated on the west side of the port and transported to the Sai Thong beach should be adopted, to mitigate the adverse effects of erosion at Sai Thong and provide an improved beach resource.

It would be useful to monitor use of the Sai Thong beach resort, if the owners agreement can be obtained, to provide information on the implications of this type of development for coastal recreation.

No special provisions are considered to be necessary with regard to power, water and other resources.

Visual impacts

Special measures to mitigate visual impacts at Map Ta Phut are not considered to be necessary. However, normal standards of good design and maintenance should be adopted to avoid visual clutter caused by port structures and equipment.

Solid waste management

Contractors should be required to make proper arrangements for disposal of wastes arising during the construction period. Dumping on the foreshore or in the sea and burning of waste should not be permitted. Dumping of wastes from ships approaching the port or into the harbour should be prohibited by harbour regulations. Provisions should be made for reception of shipboard wastes and for their safe disposal if any risk is presented to public health. Arrangements should be made with the Municipality for collection and proper disposal of solid wastes. Charges may be levied on private operators and ships generating waste for disposal.

Accidental impacts

Port approaches and operations should be regulated in accordance with international navigational standards regarding pilotage, anchorage, ship movements, etc. A prohibited anchorage should be defined within 1 km of the gas pipeline and established by international agreement. Local regulations should be issued prohibiting passage of deep draft vessels in the vicinity of the gas pipeline in waters less than 15 m deep. Handling of hazardous cargoes should be subject to approval by the Port Authority. When application for such approval is made, information should be required to enable an evaluation of the risk and the adequacy of the preventive and emergency provisions to be made. International standards on handling of dangerous cargoes should be adopted. A first aid unit, properly equipped, staffed, and trained, should be established by the Port Authority. An emergency response system should be developed in cooperation with local fire, police, and medical services, and regular exercises should be carried out to test preparedness. Port workers should be regularly informed and trained in safe working methods and emergency procedures.

Socio-economic and public health impacts

A programme of actively informing residents of the port area about the proposed development should be undertaken as soon as the decision to proceed has been taken. This will enable the population to make plans in reasonable time for relocation, new employment, schooling, etc. An orderly relocation of population would be in the interests of preventing illegal settlement. Some residents may benefit from assistance (financial or other) in relocation where they are not entitled to compensation.

To minimize public health impacts: arrangements for quarantine of vessels should be made in accordance with international practice; temporary and permanent workers should receive medical examinations and necessary treatment before starting work; facilities for first aid should be provided at the construction site and camp, and in the port; and proper sanitation should be provided during construction and operation to minimize the spread of disease.

General recommendations

Necessary conditions to achieve mitigation of impacts during construction should be stipulated in contracts for construction work and site policing: inspection should be carried out. Where activities not under the direct control of the Port Authority are to be carried out (e.g., transfer of hazardous materials from tank storage to the industrial estate), all operating methods and equipment should be subject to evaluation and approval by the Port Authority. An environmental control division (or officer) should be appointed for Map Ta Phut Port. The duties of this division should include: evaluation and approval of activities occurring in the port not under the direct control of the Port Authority; maintenance of the water supply and wastewater treatment system; collection and disposal of wastes from ships and onshore; monitoring and enforcing pollution prevention regulations affecting vessels; and carrying out regular monitoring to identify adverse environmental changes caused by pollution. The model proposed by Poston may be used as a guideline for establishing the environmental control division.

Harbour regulations should be drafted to control: discharge of liquid or solid wastes from ships approaching or moored in the port; use of reception facilities for sanitary wastewater, oily wastes, and solid wastes from ships; conditions of operation for handling dusty cargoes to minimize nuisance in the occupational and external environment and the risk of explosions; piloting, anchorage, ship movements, cargo handling; information to be provided by vessels approaching the port; conditions of approval for handling hazardous cargoes to minimize risks of fire, explosion, toxic release, or other hazard.

Environmental monitoring

The required monitoring programme for each impact has already been described, along with the mitigation measures for the convenience of a continuity of the explanation.

Concluding remarks

The EIS report is prepared in fulfilment of the requirements for preparation of an EIA of the Map Ta Phut Port Project. This study addresses the environmental impacts of the port alone; however, the overall development of the area comprises an industrial estate, an urban area, and associated infrastructure and services as well as the port.

The EIS report lacks a number of items found in formal presentation, such as the environmental base map, beneficial impacts from the project, the professionals or EIA team involved in the study, etc. Without these, the EIS really looks a bit handicapped and poses problems to the researchers. The organization of the report is not sequential and looks poor. But the analytical work is envisaged to depth, and thus the technical work is appreciable. This is one of the very few EIA case studies regarding the port development done in the region.


1 Manual of NEB Guidelines for Preparation of Environmental Impact Evaluations, National Environment Board (NEB), Bangkok, April 1979.

2 R. J. Hofer, Water Quality Management Plan for the Raoyong Map Ta Phut Development Planning Areas, Office of National Environment Board.

3 JICA, The Study on the Development of the Industrial Port on the Eastern Seaboard in the Kingdom of Thailand, Final Report, 1983.

Source: Strengthening Environmental Cooperation with Developing Countries, pp. 100-128.

Case study 10.6 EIA at Work: A Hydroelectric Project in Indonesia

Philip Paridine, Canadian International Development Agency

The proposed Lake Sentani hydroelectric development is located in the province of Irian Jaya in the extreme northeast of Indonesia. The site is near Jayapura, some 20 km from the border with Papua New Guinea. Sentani is a natural lake with an outflow through the Jafuri River eventually reaching the Pacific Ocean. By closing off the Jafuri outlet and diverting the flow through a series of channels and tunnels to Yautefa Bay, it is possible to generate hydroelectricity.

The main environmental features of the project are therefore a reduction of the Jafuri flow, manipulation of the lake water levels, input of extra fresh water into the marine system of Yautefa Bay, and terrain disturbances along the flow diversion corridor.

Sentani Lake is surrounded by 22 small villages whose residents live a traditional lifestyle. In the Yautefa Bay area fishing is practised while the diversion corridor is currently designated for high intensity development. The Sentani culture is very old and is traditionally orientated towards the lake with houses constructed on stilts in the water. This factor became a key aspect of the impact assessment.

When the Canadian-based consultant firm Acres International became involved in the Sentani Lake project in 1982, several studies had already been completed. In 1977 Tata consultants did a feasibility study which developed the flows through channels. The Tata study proposed a 10 MW plant and would have raised the lake level by 2 m, requiring relocation of the Sentani people. Subsequently, a 1975 feasibility study was performed by NEDESCO and SMEC. That consortium, also funded by the Asian Development Bank, examined the Sentani proposal and redefined it to increase the installed capacity. As in the previous study, no environmental assessment was included in the terms of reference.

Form of the assessment

In 1982 when the Canadian International Development Agency (CIDA) became involved in the project, Acres was asked to re-examine the situation. A proposal for a feasibility study and environmental reconnaissance was funded and work subsequently progressed to the design phase, during which a full EIA was conducted. An interdisciplinary environmental team worked with the designers to develop alternative scheme and integrate mitigation measures directly into the project proposal. The local population was directly consulted and the lifestyle of the lake-dwellers will continue to be possible after project development. The proposal submitted to decision makers involved a 12 MW project and decisions are now pending on construction.

Content of the assessment

There has been a growing awareness of the necessity to increase energy in this part of Indonesia. National policy is to promote development of some of the less populated areas of the country, thus creating the need for energy to supply the projected growth. The projected population increase and associated industrial activity within the Japur region over the next four years requires an increase in the generation capacity of the existing electrical system. The most economically attractive alternative involves use of the outflows from Lake Sentani as a potential hydroelectric supply. This would substitute for expensive diesel-generated electricity and permit supply to the provincial capital and surrounding region.

Scoping of studies of the existing environment

The environmental reconnaissance level study involved the fielding of a team which was on-site for six to eight weeks. The team consisted of a civil engineer, a hydrologist, a scientist, an economist, and an energy systems planner. The team operated interdependently through daily meetings. Based on an understanding of hydroelectric projects in general, and a limited database from previous studies, a generic list of impacts was established. The reconnaissance was intended to verify the database and scope issues for further studies.

The team's first priority was to establish contacts with local government, residents, the university, and anyone else who could provide baseline information and help identify the issues of importance for the local population.

During the environmental reconnaissance, the project concept became very important as it was obvious that the original 2 m water level increase would entail major impacts. The effect of alternative lake operating levels was determined as a critical area for further study and subsequent environmental information gathering was scoped accordingly.

Food availability for the Sentani people is directly related to the lake levels. Not only is the lake used for fishing, but the nearby marshes are harvested for sago. In addition, the shoreline behind the houses is used for the planting of vegetable gardens, so that lowering of lake levels during the farming season would be beneficial.

Farming was also potentially affected along the proposed corridor where rice and vegetable plots could be subject to disturbance by the construction of channels. Another aspect of the food availability issue concerned the tribes along Yautefa Bay, where traditional fishing lifestyles are followed. Possible disturbance by the sudden overflow of lake water into the marine environment was of concern.

An anticipated issue concerning lake water levels that was identified during the reconnaissance phase was that of public health. As the Sentani people use the lake as a latrine, too low a water level could spread disease, while too high a level would contaminate the shore.

Along the corridor, local planning objectives had to be considered. Ridges and swamps alternate continuously along the route. Areas that are dry and suitable for housing are limited, and estrangement of prime potential housing lots was to be avoided. Lack of land registration was of concern and projected urban growth had to be taken into consideration. National planning objectives were also of importance, since a proposed transmigration area exists south of Sentani Lake and along the Jafuri. The impacts this project would have on the water supplies and land uses for the transmigrants had to be considered.

On the basis of issues identified in the field, a scope of work was prepared for the environmental assessment and alternatives proposed for operational lake levels.

Study of alternatives

During the preparation of the environmental assessment, local people were extremely important in providing site-specific information. Although the team spent four months working on the Sentani Lake, statistically significant information could not be collected in such a short time. Where necessary, the collective memory of the Sentani people was used in lieu. Information on historical lake levels, resource utilization, and fishery in particular, was gained from the local population. Cultural information was an integral part of the data collection.

The major alternative examined during the environmental assessment was the lake level rate curve, which is the constraint governing manipulation of the water level during operation. A computer model of Sentani Lake was prepared to try various operating scenarios. The lowest constraint was dictated by sanitation levels while inundation of floorboards was the upper constraint.

For fishing, it is preferable to raise the lake level during the spring to allow the fish to spawn in their natural areas, with the water being kept high long enough for the fry to hatch and move down into the lake (thereafter drawing the lake down as fast as possible to allow people to plant their gardens).

Often a computer model is used to optimize the energy production without integrating environmental impacts. However, in this case, it was possible to achieve the same amount of energy while staying within all the environmental parameters.

As for the corridor alignment, values were placed on all of the relevant structures, so that every time a change was made, it was possible to recalculate how many houses, people, or hectares of crops would be impacted. Through land-use planning, it was possible to avoid cemeteries or schools and avoid cutting transportation paths. Hence, the corridor alignment was, in the end, quite different from that which had originally been proposed. In fact, the corridor was actually diverted considerably, to avoid land that was slated for future housing. It was also essential for the design to include safety considerations with regard to the canals.

As described above, real alternatives were considered in project design using information obtained during the environmental assessment. This resulted in some improvements being predicted for the project area including: improved fishing areas on Lake Sentani for people of Yoka near the approach channel; more recreation areas or islands in the lake from generally lower lake levels throughout the year; improved sago stands and access to swamps around Lake Sentani from generally drier conditions resulting from lower lake levels; and improved conditions in Yautefa Bay for milkfish and other estuarine species.

Environmental impacts

Despite these improvements, a number of anticipated impacts remained. Potential mitigation measures and proposed compensation were therefore summarized in the environmental assessment as follows. Construction of the hydro corridor and powerhouse will affect between 448 and 593 people, 67 to 97 structures, 30 to 45 ha of land (purchased or leased), and 25 to 145 ha of crops, depending upon the alternative chosen. The village of Puay will be the most seriously affected community on Lake Sentani as a result of weir construction on the Jafuri River. Fish resources of the upper Jafuri River will be lost and a decline in fish catches on Lake Sentani near Puay is likely. The latter is expected due to anticipated water quality degradation in this end of the lake when the natural outflow to the Jafuri River is blocked by the weir. The drying up of the upper reaches of the Jafuri River will also adversely affect Puay's accessibility to agricultural lands and wildlife (and, hence, hunting) along the river. The people of Lake Sentani will be inconvenienced by having to adapt their fish cages to a greater annual range in lake-level fluctuations. The people dependent on Yautefa Bay fisheries are likely to be adversely affected in the short term by a reduction in fish harvests until marine resources in the bay adapt to an estuarine environment. The virtual termination of lake flows to the Jafuri River will reduce mean annual flows in the Sunggrum River, although these are estimated still to be adequate for irrigation requirements currently forecast.

Mitigation measures

A number of proposals for mitigation were presented to alleviate impacts. The people currently occupying or owning lands along the hydro corridor and at the Jafuri River weir site should be compensated for buildings, lands, and crops lost or damaged as a result of the project. The people of Puay and Sekanto should receive sufficient compensation to enable them to continue their lifestyle with adequate fish resources and without the need to relocate their village. Families with fish cages around Lake Sentani prior to operation of the hydro project should be provided with screening materials to eliminate potential problems associated with a greater annual range in lake-level fluctuations. Families who regularly fish Yautefa Bay as their primary resource base should be provided with additional gill nets to off-set a possible reduction in fish harvests following construction and operation of the hydro project. Footbridges with railings across the tailrace channels in the vicinity of the fishponds and at the tailrace outlet to Yautefa Bay should be constructed to allow people continued access to both sides of the channel in these areas. Efforts should be made to restore the environment as far as possible following completion of the project, through grading, contouring, and planting.

Results of the assessment

While the project has not yet been completed, the substantial changes in design without power loss already indicate the value of the environmental assessment. Detailed actions have also been suggested for appropriate government agencies to take before construction of the project. Ensure no further development occurs on the corridor easement, including a 30 m buffer zone on either side. Provide careful inspection when staking out the easement in detail as discrepancies between technical drawings and site conditions can easily occur. Organize preparation of compensation payments for building, land, and crops, and ensure consistent and equitable treatment of individuals (including compensation for lands temporarily disrupted during construction). Planning for relocation of people and structures should begin well ahead of construction, and the affected populace should be included in the process. A reasonable schedule for relocation should be determined, and the people affected should be notified well in advance. Keep local residents well informed of project activities so they may adjust their own activities accordingly. Appoint a responsible individual to manage compensation awards for the people living around Lake Sentani, the Jafuri River, and Yautefa Bay who are expected to be impacted by the disruption to fishery resources.

During construction, it is important that a safety and environmental inspector be employed as part of the construction management contract to ensure that all necessary safety precautions are in place and that environmental recommendations contained in this report pertaining to construction activities are followed. This should include supervision of daily reporting of fish catches in the villages of Puay and Sekanto and in villages around Yautefa Bay, since these data are vital to any subsequent monitoring programme following project implementation.

Monitoring following construction

Approximately three months following project operation, a survey of Puay, Sekanto, and Yautefa Bay fisheries should be undertaken to determine impacts and assess whether further mitigation is warranted. This should be undertaken by the safety and environmental inspector. Approximately one to two years following commencement of hydro operations, it is strongly recommended that a comprehensive environmental evaluation be carried out to compare post-project conditions with impact predictions. The need for further mitigation based on the above assessment should be documented as part of the monitoring programme. Further environmental monitoring is recommended five years after hydro operation using a similar programme to that outlined above.


While some government authorities in Jakarta were initially skeptical about the environmental assessment, attitudes changed as the results started to be known. It became evident that the project design and operation could change without affecting the cost-benefit ratio of the project. Government agencies, locally and in Jayapura, provided the study group with information requested, although constraints on horizontal coordination limited the ability of the team to discuss the project with various ministries.

Unfortunately, the university and environmental studies centre could not provide the group with technically skilled personnel. Although keen to assist in any way, the resources were not available to offer. Ultimately, however, a useful baseline study was completed. Fortunately, local people were always willing to give information about their lives and priorities and this compensated somewhat for the lack of technical knowledge.

One specific constraint was a requirement that local people not be told about the proposed hydroelectric project. Therefore, questions had to be formulated in an odd manner, which tended to make them suspicious.

To sum up, the Sentani project demonstrates the value of incorporating environmental factors early in the planning process, such as during reconnaissance. Because of this, key decisions were made early to allow changes to the project before designs were set. The value of scoping a list of issues to consider was also demonstrated. It allowed focusing on the right questions and eliminated costly and delaying studies.

Integration of the environmental team with the overall project team allowed a major impact, potentially involving the relocation of 60,000 people, to be avoided. It also permitted optimization of resource utilization in the proposed project operations.

Because of effective communication with local people, the study was able to obtain information that was not available as published baseline data. This made a critical difference to project design. The involvement and cooperation of local agencies was also essential.

Finally, the importance of monitoring must be emphasized. It is impossible to quantify everything, especially with so little reference material on which to base some key predictions. Thus monitoring is absolutely necessary to make sure that the study and design are correctly verified and implemented, and that the mitigation measures that were proposed actually work.

Case study 10.7 The Greater Cairo Wastewater Project

Mohamed Talaat Abu-Saada, Cairo Wastewater Organization, Egypt, and Stephen F. Lintner, US Agency for International Development

Note: This is an example of a case study where environmental aspects have not been costed.

The Greater Cairo Wastewater Project, undertaken jointly by the Arab Republic of Egypt and the United States, is an excellent example of how environmental assessments can be used to assist host countries and donor organizations in the evaluation of phased implementation strategies for major projects, the selection of technology, the evaluation of operation and maintenance issues, and in the identification of complementary projects to assure sustainable performance of the project. This experience can be helpful when preparing environmental assessments for other projects in developing countries.

In 1976, the Arab Republic of Egypt embarked on a massive undertaking to improve the wastewater collection, treatment, and disposal systems for the capital city of Cairo. The objectives of the project were to improve wastewater collection, conveyance, treatment, and disposal in the metropolitan region. The implementation of this undertaking has been assigned to the Cairo Wastewater Organization (CWO), while the operation of the system is the responsibility of the Cairo General Organization for Sewerage and Sanitary Drainage (CGOSD). The project involves not only extensive rehabilitation of existing facilities, relief pump stations and force mains, but new construction as well, including major wastewater treatment plants and disposal systems. Additional project activities will provide extensive support for institutional development and training programmes. In addition, the Ministry of Health will conduct water quality monitoring on a regular basis.

The city is geographically divided into two banks, East and West, by the River Nile. The East Bank, the oldest portion of the city, has an extensive wastewater system dating back to 1906. The West Bank wastewater system, which was constructed in the 1930s, is not as extensive, and as a result, the West Bank has a higher proportion of its population living in unsewered areas.

During the planning stages for the Greater Cairo Wastewater Project, consideration was given to these various structural differences and the varying needs of the areas. As a result, East Bank improvements focus on the construction of a major conveyance system, to carry existing and future wastewater to a new treatment plant at Gabel el Asfar. Construction activities for the West Bank are more extensive. They include the expansion of basic collection and conveyance facilities in the extensively unsewered areas, rehabilitation and expansion of the Zenein wastewater treatment plant, and the construction of a greatly expanded wastewater treatment plant at Abu Rawash.

The need for the project

Cairo, like many capital cities in the developing world, has been faced with the problem of supplying wastewater services to a population which is growing as the result of both rapid natural population growth and high rates of rural-urban migration. The 1985 population of the metropolitan region was estimated at approximately 8 million and is projected to reach approximately 13.6 million by the year 2000. In serving a population that is increasing at a rapid rate, the Cairo wastewater system, which was originally designed for a population of less than 1 million, had become seriously overloaded and deteriorating to a point where unsanitary conditions were developing throughout much of the city. Inadequate investment in maintenance, especially for pump stations and sewers, further reduced the efficiency of the system. In addition, many areas around Cairo have never been sewered, even though many had been supplied with piped water.

Presently, about 66 per cent of the population is served by the existing sewerage system and 34 percent reside in unsewered areas. The reliability of collection in the sewered areas is reduced due to the general overloading of the system and inadequate pumping capacity. In the unsewered areas, populations rely on a combination of public and private services for the collection of wastewater from vaults below or adjacent to houses. These devices frequently overflow or become inoperable, resulting in the large-scale flooding, ponding, and pollution of entire neighbourhoods. The high cost of commercial collection of wastewater in the predominantly lower income unsewered areas, discourages all but the most essential use of the sewage disposal pits in these areas and promotes a variety of improper disposal practices. Because of these conditions, studies have shown that the rate of illness is higher in the unsewered urban areas of Cairo than in most rural areas in Egypt.

Approximately one half of the sewage collected receives partial wastewater treatment prior to disposal. The remainder, including that collected from unsewered areas, is disposed directly into open drains originally constructed for agricultural purposes which have become an element of the urban wastewater infrastructure. These drains eventually discharge into the Nile delta resulting in local degradation of water quality. Wastewater from industry and thermal power generation is not a significant problem in Cairo due to the concentration of these facilities to the north and south of the city outside the service area of the system.

The negative impact of this situation on environmental health and water quality is recognized by the Government of Egypt, which has given top priority among infrastructure investments to the Greater Cairo Wastewater Project. The project has broad recognition of the need to make improvements in the system. This attitude has been important as there has been considerable local disruption of traffic and business during the implementation of the project.

Donor support

The Government of the United States acting through the United States Agency for International Development (USAID) and the Government of the United Kingdom acting through the Overseas Development Administration (ODA) have provided capital and technical support for this project, as well as private British banks. Assistance is also being provided by the Federal Republic of Germany and Japan. Local currency costs are being provided in part by the Government of Egypt. A major element of technical assistance has been supported for the design of both the rehabilitation and new construction phases of the project by a jointly financed British-American engineering consortium named AMBRIC. AMBRIC works in collaboration with a consortium of Egyptian firms.

The total project cost is expected to be more than $3 billion. Supplemental studies, including environmental assessment, tariff studies, unsewered area studies, environmental health review, etc., cost $1.5 million and were funded by USAID.

Rehabilitation phase

The existing wastewater system includes over 400 km of common sewers, 82 pneumatic ejector stations, 95 conventional pumping stations, and approximately 120 km of major collectors, in addition to five wastewater treatment plants. Due to excessive deterioration of the system, a multi-faceted rehabilitation programme was implemented between 1980 and 1986.

The work supported under the rehabilitation phase of the project consisted of major and minor repairs, structural and equipment modifications, debris and grit removal, and general cleanup of the system. Work was conducted on five major system elements: collectors and sewers, ejectors and ejector stations, pumps and pump stations, force mains, and treatment plants. This phase provided for a substantial improvement in the performance of the existing system.

The rehabilitation phase not only reduced the problems associated with the wastewater system, that is, flooding and ponding of sewerage, but it also provided a foundation for developing most of the detailed plans and construction specifications for expanding and improving the system to serve the population of Greater Cairo.

New construction phase

On the East Bank, a major conveyance system is planned which will carry wastewater from the existing sewer collection system to a major tunnel pumping station at America, which will have installed a centrifugal pump. From America, a new 15 km culvert conveyance system will transport wastewater northward to two plants, a new locally designed treatment plant at Shoubra el Kheima and a major new activated sludge treatment plant at Gabal el Asfar. The Gabal el Asfar wastewater treatment plant will be a non-nitrifying activated sludge plant with thickening and drying facilities.

Construction activities on the West Bank have been designed to improve and expand the wastewater system and to assure its proper management. To meet these design criteria, construction will include deep collectors to allow the elimination of 12 existing pumping stations, steep gradients to assure an adequate scouring velocity where incursion of sand is a problem, and simple archimedean screw-type pumps for major pump stations. With regard to the expandability of the system, primary collectors will have the capacity not only for current volume, but for extension of services to present unsewered areas and to adjacent developing areas.

Besides providing sewerage services to unsewered areas, additional activities focus on construction of a new treatment plant at Abu Rawash. The plant is a non-nitrifying activated sludge design and is expected to treat flows reaching 400,000 m3 per day. The design minimizes both energy cost and maintenance. Based on the examination of the system, the Zenein plant was the only treatment plant considered suitable for retention in the system. The plant will undergo extensive modifications during this phase, which will result in an operational capacity of 300,000 m3 per day.

Operational assistance and training

In order to assure the reliable performance of the Cairo wastewater system, the Government of Egypt and USAID have started implementation of a series of institutional development and training programmes in operation and maintenance. The programme has focused on the development of improved institutional capabilities in administration, planning, and financial management. Extensive support has been provided for the "training of trainers'' in a wide variety of professional, administrative, and technical skill areas. Special attention has been given to critical problems such as the management of grit accumulations in the sewers, sewer cleaning, pump station operation, and wastewater treatment plant operations.

The West Bank environment assessment

USAID is required by United States law (22 CFR 216 "USAID Environmental Procedures'') to prepare environmental assessments for all projects which are anticipated to have a potentially significant impact on the environment. All major water and wastewater projects are specifically required under this legislation to have an environmental assessment prepared to ensure that they are planned, designed, and implemented in an environmentally sound manner. The Arab Republic of Egypt, although not specifically requiring the preparation of environmental assessments, requires that proposed projects be reviewed for compliance with a variety of laws and regulations concerning the environment.

Under USAID regulations, an environmental assessment is defined as a detailed study of the reasonably foreseeable significant effects, both beneficial and adverse, of a proposed action on the environment. The objective of an environmental assessment is to identify potential environmental consequences of a proposed project to ensure that the responsible decision makers in both the host country and USAID make an environmentally informed decision when reviewing and approving a proposed project and implementation plan. Included in the assessment is a detailed evaluation of alternatives to the proposed project and the identification of mitigation actions which might be adopted to eliminate or reduce unavoidable negative environmental impacts.

It should be understood that under the USAID approach, environmental assessments do not recommend a specific course of action, nor do they determine whether a project should or should not be undertaken. These decisions are reserved for resolution by USAID and host government personnel during the process of project design, review, approval, and implementation. This is important, as it makes the assessment a "dynamic'' tool to ensure environmental soundness, rather than a "completed'' document prepared to assure compliance with a regulatory requirement. The value of an environmental assessment in the USAID system is that it provides information concerning key environmental issues, an analysis of alternatives and reviews potential mitigation actions. This information is then evaluated with other detailed analyses relating to engineering, economics, management, training, and financing to provide an effective and environmentally sound project design and implementation plan.

An agreement was reached early in the design of the Greater Cairo Wastewater Project that the Government of the United States would provide assistance for capital construction on the West Bank of the Nile and the Government of the United Kingdom would provide assistance for capital construction on the East Bank of the Nile. Initially, it was anticipated that the AMBRIC model used for design of the system could be extended to joint USAID-ODA preparation of a detailed environmental assessment. However, for a number of reasons this did not prove possible and USAID proceeded to fund the preparation of a detailed environmental assessment for the proposed West Bank construction programme.

Preparation of the environmental assessment

CWO and USAID recognized the need for the preparation of a detailed environmental assessment from the earliest stages of project development. An element of the initial design studies prepared by the AMBRIC Consortium included a preliminary environmental review of the project. The Washington-based Environmental Coordinator of the Bureau for Asia and Near East of AID made preliminary site visits to the project area and held discussions with representatives of CWO during April 1979 to review the proposed new construction programme on both the East and West Banks of the Nile. The scope of work for the environmental assessment was prepared by the environmental coordinator with the assistance of CWO during visits to Egypt during November 1980 and March 1981. The environmental coordinator returned to Egypt to supervise the initial phases of field data collection with representatives of the consulting firm retained to prepare the assessment and in October 1981 to participate in the CWO sponsored "scoping session''. The planning visits to Egypt allowed for the advance collection of a variety of data and for coordination with the AMBRIC and Egyptian consortiums.

The environmental assessment was prepared for the General Organization for Sewerage and Sanitary Drainage and the Organization for Execution of the Greater Cairo Wastewater Project CWO by American and Egyptian consultants. The total cost for preparation of the assessment was approximately $270,000, which was grant-financed by USAID. It was prepared over a 12-month period which included significant periods for the review of draft versions of the document.

The study was prepared by a 12-person interdisciplinary team of experts from the United States and Egypt which included specialists in agricultural engineering, agronomy, economic analysis of capital projects, economic analysis of natural resources issues, environmental engineering, Egyptian law, industrial pollution control, public health, soil science, social science, and wastewater systems operations and maintenance. The assessment was prepared in two volumes: an executive summary (in Arabic and English) and a main report (in English with an Arabic summary and table of contents).

Preparation of the environmental assessment for the Greater Cairo Wastewater Project included the conduct of the first environmental "scoping session'' held in Egypt. A requirement under USAID environmental regulations, a "scoping session'' is a meeting of knowledgeable and potentially affected parties to review the proposed scope of work of the environmental assessment and to provide advice concerning the preparation of the study.

The session for the project was hosted and chaired by CWO and had 31 participants. These included representatives of Ain Shams University, AMBRIC, Ministry of Agriculture, CWO, General Organization for Physical Planning, Ministry of Health, Ministry of Irrigation, National Committee on Environment, University of Alexandria, and USAID. The preparation of the assessments benefited significantly from this session which allowed for the improved targeting of field efforts, identification of key sources of data, and the establishment of high level contacts with senior representatives of major governmental and technical organizations.

Major issues reviewed in the environmental assessment

The environmental assessment focused on the review of the current environmental conditions in the greater project area, an analysis of the causes of these problems, an analysis of alternative wastewater management plans, a review of wastewater collection and conveyance alternatives and their environmental impacts, and a review of wastewater treatment and disposal alternatives and the environmental aspects of the following issues: alternatives for the sequence of facilities construction; alternatives for wastewater treatment; and alternatives for effluent disposal.

Each of the alternatives was reviewed with regard to its cost, its reliability under local conditions, the associated environmental health benefits, and its institutional requirements, and social acceptability in the Egyptian context. The assessment emphasized the evaluation of alternatives with regard to both the impact of new facilities as elements of a well conceived and well run system, but also those impacts which could result if portions of the system do not function as intended. It also analysed constraints to efficient operations such as inadequate tariffs, non-enforcement of sewer use ordinances, and inadequate resources for spare parts.

The project design of the Government of Egypt and USAID made extensive use of the environmental assessment in the development of a strategy for phased investment. Based on the assessment, first priority was given to collection and conveyance investments, with second priority given to treatment disposal investments. The environmental assessment was also used to justify the need to identify and obligate significant additional funding by both governments to assure successful implementation of the complete project.

It was recognized that the emphasis on collection and conveyance would provide for rapid and significant improvements in environmental health for large numbers of residents in areas which were either unsewered or subject to routine flooding due to inadequate conveyance. However, it was understood that this decision would continue on an interim basis, the long standing practice of discharging untreated wastewater to agricultural drains.

It should be noted that the analysis included in the environmental assessment showed that while this would temporarily result in a minor negative incremental impact to water quality, the benefits obtained from construction of permanent facilities for the removal of untreated wastewater from densely populated areas justified this decision. In addition, the risk associated with this investment strategy was limited due to the small amounts and restricted range of industrial pollutants discharged into the West Bank collection system.

Lessons learned about environmental assessments

Timing is all important

The experience of the Greater Cairo Wastewater Project demonstrates that environmental assessments for major capital development projects can be prepared in a cost-effective and timely manner when they are prepared at an appropriate point in the course of project development. CWO and USAID believe that the funds spent to prepare the environmental assessment represent an effective expenditure of $270,000 to support the approximately $1.4 billion of new construction for the West Bank section of the Greater Cairo Wastewater Project.

USAID experience is that environmental assessments of major capital projects are best done following the preparation of the preliminary feasibility study, which allows for a clear identification of the proposed project and alternatives. The environmental assessment, to be an effective tool in decision making, should be available for concurrent review with the feasibility study. USAID does not recommend that any project be authorized to go to final engineering design and/or construction prior to the preparation, review, and clearance of a detailed environmental assessment.

The costs of environmental assessments can be minimized if selected data collection needs are identified early and are included in the basic data collection programme for the engineering feasibility study. Savings can also be achieved by requiring the engineering consultant to allow the environmental assessment team to use base maps, system plans, technical data, and cartographic drafting bases.

EIA should be an on-going review process

The experience of the Greater Cairo Wastewater Project illustrates that the initial environmental assessment is only one element of a continuous environmental review process which should be used by host countries and donors in the planning, design, implementation, and operation of a major capital development project.

It should be noted that the Greater Cairo Wastewater Project was actually subject to a series of field-based environmental reviews by USAID environmental personnel: (a) prior to the preparation of the detailed environmental assessment, (b) during the technical review of final engineering designs for selected elements of the project, and (c) through periodic field reviews.

Most important in assuring sound project implementation are the annual reviews of the water and wastewater sector which are held by the Governments of Egypt and the United States. These sessions allow for the routine assessment of progress, the timely identification of problems, and the joint resolution of issues. This continuous process is critical to assure that a project is planned, designed, and implemented in an environmentally sound fashion as opposed to only being subject to the preparation of a detailed environmental assessment as a legal or policy requirement.

EIA can help establish phased investment strategies and technology selection

The experience of the Greater Cairo Wastewater Project demonstrates that environmental assessments can be designed to provide insight into complex project design decisions such as the selection of phased investment priorities and technology selection in a large-scale project. The environmental assessment was an important tool for the CWO and USAID in making the difficult decisions on the sequence of construction elements, in order to optimize environmental health benefits in a project with an implementation period of over a decade. The environmental assessment assisted in the selection of technology for wastewater collection, treatment, conveyance, temporary disposal, and permanent disposal.

The usefulness of the environmental assessment in the project design and implementation process was enhanced by the fact that the analysis of all technical alternatives and mitigations proposed in the environmental assessment included an evaluation of their capital cost (foreign and local currency), recurrent cost (foreign and local currency), institutional development and training requirements, and the identification of the responsible implementing organization. This information proved critical to decision-making as it provided information on the cost and managerial implications of various options.

EIA should provide an integrated analysis for programme planning

The experience of the Greater Cairo Wastewater Project demonstrates that an environmental assessment can influence the decisions of host country and donor officials identifying major problems requiring resolution, providing a basis for policy, review, and serving as advocacy documents to obtain support for project funding. The environmental assessment identified a series of issues which represented generic problems in the management of wastewater in Egypt. It reviewed the problems of institutional development, operation and maintenance, system reliability, and the financing of recurrent costs. By providing an integrated and objective analysis of the current status of wastewater services on the West Bank of Cairo and an assessment of the potential human health impacts of this situation, the assessment served as an advocacy document for justifying the provision of support for complementary project activities in institutional development, operation and maintenance, and training.

A major outgrowth of the assessment is the Water and Wastewater Institutional Development Project approved in 1985 with joint Government of Egypt and USAID funding of $420 million. The assesment brought to the attention of the host government and donor organizations the serious negative environmental impacts which can occur when systems fail to operate as planned due to inadequate design, poor construction, or improper operation. It stressed the critical role played by properly prepared institutions and trained personnel in assuring that the environmental objectives of the project are achieved on a sustainable basis.

The importance of "scoping sessions''

The experience of the Greater Cairo Wastewater Project demonstrates the utility of conducting "scoping sessions'' as part of the process for the preparation of environmental assessments. The USAID environmental procedures require that "scoping sessions'' be conducted as an element of the environmental assessment preparation process. However, the experience in the Cairo study, and other studies, indicates that the sessions provide an important mechanism to assure widespread knowledge of the proposed project, the potential environmental impacts, alternatives, and possible mitigation activities.

Scoping sessions provide a forum for the participants, the project sponsor, and the assessment team to interact to obtain a consensus on such things as the critical environmental issues which should be reviewed, the critical organizations and individuals to be contacted, and location of the important sources of data. It also provides a means for establishing contacts to ensure that senior level personnel instruct their staffs to provide assistance to the team and logistical support for field visits. CWO and USAID attribute much of the $78,000 in savings which was realized by the consultant in the preparation of the assessment as attributable to the contacts made at the scooping session.

The advantages of a "joint team'' approach

The experience of the Greater Cairo Wastewater Project demonstrates that the use of joint teams comprised of personnel from the host country and international consulting organizations is a technically sound and cost-effective practice. The preparation of the environmental assessment benefited from the use of an Egyptian private sector consulting organization as a subcontractor which provided both professional personnel, support personnel, and logistical assistance. This association increased the efficiency of the personnel provided by the international consultant and provided direct access into the well developed Egyptian consulting community. It also reduced the time required by CWO and USAID to support the field operations of the international consultant.

The "joint team'' approach provided the Egyptian subcontractor with an opportunity to expand their area of expertise and to develop a potentially long-term relationship with a firm from the United States. USAID has continued to use this approach for the preparation of environmental assessments throughout the Asia and Near East Region. For example, a major Pakistan-USAID environmental assessment was prepared recently by a joint team which included five experts from an American consulting firm and five experts from an associated Pakistani firm.

Host governments and donors should recognize, however, that the use of joint teams requires the adoption of a policy which promotes collaborative preparation of consultant studies. USAID believes that the joint preparation of environmental assessments is an effective technique for the transfer of this methodology when this is a planned objective of technical assistance and provisions are made in the consultant contract to assure this will occur. It is recommended that when joint teams are proposed to prepare environmental assessments the scope of work should include a provision for the international firm to review the objectives and methodology of the environmental assessment with the local firm. The scope of work for the local firm should include provision for review of local customs, laws, regulations, and institutions with the international firm.

The need for a flexible review and comment process

The experience of the Cairo Wastewater Project demonstrated the need to adopt a flexible approach to the review and comment process for environmental assessments. In most countries, developed and developing alike, personnel in governmental and non-governmental organizations are limited in their ability to review and comment on the large amounts of material which are routinely submitted to their offices. The traditional system used in the United States of soliciting formal written comments in response to a draft assessment is not an efficient way to obtain comments in the Near Eastern context. For a number of reasons, it is difficult for many organizations to provide written comments in a timely fashion (60 to 90 day review and comment period). After a major extension of the review period, CWO and USAID conducted visits to a number of key individuals to obtain their comments. This proved to be a satisfactory although informal means of obtaining responses to the draft and final assessment.

As the result of this type of experience in Egypt and other countries in the Asia and Near East Region, USAID has adopted a mixed approach to review and comment on assessments which includes formal written comments, small group meetings to review draft documents, and consultations with key individuals. USAID has found that the preparation and distribution of independently bound executive summaries greatly assists in providing senior level personnel, who do not have the time to review the complete assessment, with an opportunity to review the major findings and recommendations of the study.

Other titles of interest

Management of Latin American River Basins
Amazon, Plata, and SFrancisco
Edited by Asit K. Biswas, Newton V. Cordeiro, Benedito P.F. Braga, and Cecilia Tortajada

This book gathers expert analyses of issues surrounding three of Latin America's largest and most important rivers, including inter-state and intra-state conflicts over their fair and sustainable use.

ISBN 92-808-1012-X
paper; 360pp; US$29.95

Central Eurasian Water Crisis
Caspian, Aral, and Dead Seas
Edited by Iwao Kobori and Michael H. Glantz

Central Eurasian Water Crisis refers to the awareness by the global community that, in the 21st century, people in various regions around the world will likely face problems of water quality and water quantity. These problems have already surfaced in several locations, and this volume focuses on three of them: the Dead Sea region, the Aral Sea region, and the Caspian Sea region. Researchers from a variety of physical and social science disciplines seek to identify the water-related problems and the prospects for resolving them.

ISBN 92-808-0925-3
paper; 214pp; US$24.95

Managing Water for Peace in the Middle East
Alternative Strategies
By Masahiro Murakami

This volume evaluates some non-conventional approaches to resolving water resource issues in the Middle East. The text draws on studies involving Kuwait, Jordan, the Palestinian territories, and Israel.

ISBN 92-808-0858-3
paper; 320pp; US$35

Hydropolitics Along the Jordan River
Scarce Water and Its Impact on the Arab-Israeli Conflict
By Aaron T. Wolf

This book argues that the Jordan River watershed - a region where some of the worst Arab-Israeli conflict has occurred - might be the very place to bury ancient hatreds and work to give birth to new and more enlightened environmental collaborations.

ISBN 92-808-0859-1
paper; 280pp: US$35

United Nations
University Press
53-70, Jingumae 5-chome
Shibuya-ku, Tokyo 150-8925, Japan
Tel: +81-3-3499-2811 Fax: +81-3-3406-7345
e-mail: [email protected]

Environmental Impact Assessment (EIA) is a policy and management tool for planning and decision-making. Conceived in the 1970s after the United Nations Conference on the Environment in Stockholm, EIA assists policy makers and the general public in identifying, predicting, and evaluating the environmental impact and consequences of proposed development projects, plans and policies. The outcome of an EIA study helps to decide whether a given project should be implemented and what form it should take.

This volume includes an introduction to EIA, and explains its process, methods, and tools. It discusses the implementation of specific environmental management measures and the need for their constant monitoring. The authors also explore the writing and reviewing of an EIA report and the process of translating and communicating the findings of an EIA study to decision makers and the public. The book also examines emerging trends in EIA and concludes with a number of illustrative case studies.

is with the Environmental Management
Centre, Bombay.

is President of the Third World Centre for
Water Management, Mexico City.

United Nations
University Press

ISBN 92-808-0965-2