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close this bookEnvironmental Handbook Volume I: Introduction, Cross-sectoral Planning, Infrastructure (GTZ, 1995, 591 p.)
close this folderGuidelines for conducting a comprehensive study of a project's environmental aspects
View the document(introduction...)
View the document1. Definition of the area(s) affected
View the document2. Existing stresses and stability/stress resistance of ecosystems
View the document3. Description of stresses originating from the project
View the document4. Assessment of future overall stresses and their impacts
View the document5. Recommendations for environmentally sound options
View the document6. Overall assessment and decision-making aids


A. Necessity of an environmental study

Ascertainment and consideration of likely environmental impacts is an essential part of project planning1). The necessary scope of a study on environmental impacts and environmentally sound project design will depend on the extent of the anticipated environmental stresses, the sensitivity of the environmental components requiring protection, the complexity of the project, the availability of information and the stage of appraisal. Particular attention must be focused on projects which typically involve major environmental risks, such as industrial plants producing significant emissions (e.g. refineries), infrastructure measures whose potential impacts are difficult to assess (e.g. construction of new cross-country roads/effects resulting from accessibility) and projects involving extensive interference with the balance of nature (e.g. mining, wood production, utilisation of water etc.). A detailed study will generally be required in such cases.

1) The purpose of the study is to provide a basis for project planning and appraisal. The results may be presented in the form of a separate study or as part of a feasibility study.

The following key environmental aspects must also be considered for other environmentally relevant projects:

- actual ecological situation in the project region or with respect to specific ecosystem

- existing stresses on the various ecosystems in the planned project location and their likely development if the project is not implemented (baseline state)

- description of the additional stresses imposed by the project and its alternatives

- estimation of future overall stresses

- interaction between ecological, economic, cultural and social effects

- impacts on women to be considered separately

- recommendations for environmentally sound options (alternative methods, emission-limiting requirements), including determination of suitable location

- overall evaluation

In order to lay down the framework and likely focal areas of an environmental study, the nature, reach and significance of the planned project's potential environmental impacts must be estimated with the aid of the usual documentation and relevant materials. The basis is provided by information about the project's design and context, the occurrence, dispersal and eventual whereabouts of pollutants, direct and indirect physical interference with ecosystems that affects natural cycling systems, and primary and anticipated secondary impacts on the socio-economic situation of the project region's population. Appropriate terms of reference for the study must then be elaborated on the basis of this information.

B. Basis for investigating environmental impacts

1. Initial information can be derived from the project documents. It must be ensured that these documents provide concrete details that can be drawn upon in assessing environmental aspects. This applies in particular to areas of significance both in technical and economic terms as well as from the ecological viewpoint. Foremost among these are the following:

- use of natural resources
- use of land
- transport situation
- (waste) disposal
- energy consumption
- socio-economic and cultural context
- impacts on upstream and downstream sectors

Where necessary, more detailed information is to be collected during elaboration of a feasibility study, making use of local knowledge where appropriate.

2. In order to determine who is to compile the study and with whose assistance, it is necessary to ascertain the existing scientific and technical expertise, the regulations applied and the extent to which statutory requirements and relevant findings are put into practice. If the structures for ensuring compliance with environmental requirements are considered effective, for example, the environmental study may be confined to particularly difficult and atypical problems.

C. Content and structure of the environmental study

The structure set out below is intended to help ensure that account is taken of all significant environmental impacts in the project region as well as upstream and downstream sectors. Experience has shown that serious environmental damage occurs in cases where follow-on problems were not spotted in advance; one way of preventing such a development is to lay down comprehensive terms of reference. The structure given should be regarded as the maximum scope for a study and is to be used in its complete form whenever complex environmental impacts (as described in A above) are anticipated.

1. Definition of the area(s) affected

1.1 Climate and weather


radiation, air temperature, atmospheric pressure, humidity, precipita-tion, evaporation, direction and speed of wind


inversions, frequency of fog, local winds

Weather risks:

storms, sandstorms and dust storms, hail, torrential downpours, high water, flooding

Risk of natural disasters:

earthquakes, volcanic eruptions, typhoons etc.

1.2 Soil and groundwater

- Soil type
- Soil stability (landslip and erosion risks)
- Soil fertility
- Groundwater resources and their quality
- Groundwater formation and flow
- Geological structure, nature of rock, tectonics
- Groundwater recharge and flow

1.3 Hydrological cycle

- Information on the aquatic ecosystem
- Flowing waters with details of yearly flow and water quality, catchment areas
- Stagnant waters
- Coasts and seas
- Use of waters for fishing
- Obtaining drinking-water supplies
- Other uses

1.4 Vegetation and land use

- Existence of regional planning

- Agriculture: field use, livestock husbandry, irrigation, terracing (large-scale, with use of fertilisers, pesticides etc.)

- Forestry: commercial timber, fuelwood, natural forest, plantations

- Industrial areas

- Transport routes

- Other infrastructure

- Tourist areas/recreational areas

- Functions as a natural environment (particularly sensitive in ecological terms)

- Protected areas

1.5 Flora and fauna with particular reference to their need for protection

- Protected and endangered species (taking into account their position within the ecosystem)

- Beneficial and non-beneficial species

- Fauna and flora as the basis of the food supply

1.6 Population and settlement

- Size of population, age structure, gender index
- Population density/pressure and carrying capacity
- Sources of income and gainful activity2)
- Nutrition, health status
- Level of education, illiteracy rate
- Fuel and water consumption, quantities of solid wastes and wastewater
- Ways of life on the basis of nature and form of land use
- Environmental awareness, attitude towards nature
- Structures for averting and coping with natural disasters
- Form of settlement in the vicinity of the possible project location

2) Study of gender-specific environmental relevance.

1.7 Components of the ecosystem meriting particular protection, miscellaneous

- Natural resources: groundwater, bodies of surface water (e.g. containing large fish stocks), soils (e.g. arable farming), woodlands, mineral resources, ecosystems meriting protection, endangered species (conventions on protection of species, international protection regulations etc.), areas meriting protection for cultural reasons

- Cultural monuments, historical buildings

- Established settlement and social structures

- Settlement landscape and natural landscape

2. Existing stresses and stability/stress resistance of ecosystems

2.1 Atmospheric pollution

(Dust/fine dust including proportion of heavy metals, sulphur dioxide, nitrogen oxide, carbon monoxide, chlorine and fluorine compounds, organic and carcinogenic substances, radionuclides, pathogens, odours, greenhouse gases)

2.2 Stresses and risks affecting soil and groundwater

- Pollution: content in respect of heavy metals, radionuclides and persistent organic compounds from pesticides, bactericides and fertilisers, pathogens

- Risks to soils caused by erosion, changes in pH value, denudation, nutrient leaching, compaction, salinisation, acidification, puddling

- Pollution of groundwater (as for soil)

- Adverse changes in groundwater recharge and groundwater level

2.3 Stresses and risks affecting surface waters

- Pollution(Oxygen content, inorganic substances such as salts and heavy metals, organic substances such as pesticides and bactericides, suspended solids, radionuclides, summation parameters for biochemical and chemical oxygen demand, turbidity, odour, taste, temperature, flow velocity, pH value, pathogens and waterborne diseases)

- Disturbances of the water balance(changes in flow, drawing-off of water, changes in annual characteristics, change in groundwater level)

2.4 Noise and vibration (indicating local habits)

2.5 Stresses and risks affecting the ecosystem as a whole

2.6 Stresses and risks affecting particular species (flora and fauna)

2.7 Special risks

- Epidemics
- Earthquakes, volcanic activity, landslides, earth subsidence
- Storms
- High water and flooding
- Torrential downpours and hail
- Insect pests (e.g. migratory and other locusts)

3. Description of stresses originating from the project

3.1 Description of processes and project activities with environmental relevance

- Products/economic goal

- Description of process, including information on transportation, storage and handling of toxic substances

- Raw materials and equipment used

- Residual (waste) materials, solid wastes and wastewater

- Energy requirements

- Possible malfunctions/operating problems and their consequences

- Planned occupational safety measures

3.2 Direct stresses and risks originating from the project

3.2.1 Atmospheric emissions (Individual aspects as in 2.1)

3.2.2 Introduction of substances into surface waters and groundwater (Individual aspects as in 2.2 and 2.3)

3.2.3 Introduction of substances into the soil (as a sink)

3.2.4 Waste materials, solid wastes and wastewater

- Quantity and nature of waste materials, solid wastes and wastewater produced
- Recycling in connection with the project
- Disposal facilities created specially for the project
- Guaranteed connection to proper disposal systems

(If special recycling or disposal facilities are necessary for industrial projects or large-scale settlement projects, these must undergo environmental impact assessment in connection with the project or separately.)

- Eventual destination of excavated material or mining waste

3.2.5 Noise and vibration

3.3 Indirect impacts of the project

3.3.1 Impacts resulting from extraction of mineral resources for use as materials in the planned project

3.3.2 Impacts of the project on use of groundwater and surface water and on drawing-off of water

3.3.3 Impacts resulting from the use of self-regenerating and non-self-regenerating resources

3.3.4 Impacts resulting from expansion and intensification of land use (including consequences of displacing previous users)

3.3.5 Impacts resulting from off-project disposal of solid wastes

3.3.6 Impacts of infrastructure measures

3.3.7 Impacts occurring during the construction phase

- Energy consumption and meeting of energy requirements
- Potential labour force
- Socio-economic impacts (new settlements, increased gender-specific workload etc.)

4. Assessment of future overall stresses and their impacts

4.1 Overall stresses affecting the individual subsystems and comparison with quantitative/qualitative standards

4.1.1 Atmospheric pollution (Individual aspects as above)

4.1.2 Stresses affecting surface waters and groundwater (Individual aspects as above)

4.1.3 Stresses resulting from recycling of residual (waste) materials and from disposal of solid wastes and wastewater

- in connection with the project (cf. 3.2.4)
- outside the project (cf. 3.2.4)

4.1.4 Stresses affecting the soil (Individual aspects as above)

4.1.5 Stresses caused by noise and vibration

4.1.6 Stresses affecting flora and fauna

4.1.7 Stresses affecting the entire ecosystem

4.2 Impacts of future environmental stresses on environmental components requiring protection

4.2.1 Health and well-being

- Health and safety of employees/users

- Direct adverse effects: immissions caused by air pollution, noise and vibration, pollutants in drinking water, pollutants in food, occurrence of pathogens fostered by presence of wastewater and solid wastes

- Indirect impacts: breaking-up of living environments through construction of traffic routes, destruction of settlement landscape by large buildings, resettlement necessitated by large-scale projects, disruption of traditional ways of life, possibility of uncontrolled new settlement

4.2.2 Microclimate

(Air temperature, duration of shade, evaporation rate, amount of precipitation, wind circulation, frequency of fog, formation of haze, risk of frost).

4.2.3 Soil and groundwater

(Salinisation, nutrient leaching, puddling, compaction, erosion, desertification, soil organisms).

4.2.4 Surface waters

(Eutrophication, degradation, canalisation, impounding to create stagnant waters, aquatic fauna and flora).

4.2.5 Vegetation and land use

(Exclusion of various forms of use, building over, sealing of open areas, monoculture, permitting of changes in land use).

4.2.6 Flora and fauna

(Eradication of endangered species [has a study of an international convention on species protection been carried out], breaking-up of living environments and migratory routes, changes in the spectrum of species).

4.2.7 Physical and cultural assets meriting protection

(Corrosion of structures, loss of historical buildings, impairment of suitability for recreational purposes [loss as a tourist destination], devaluation of residential areas, religious facilities).

4.2.8 Adverse effects on other forms of economic activity

4.3 Summary and weighting of stresses and disturbances likely on the basis of point 4, where appropriate with special consideration of their contribution to global environmental problems

(It must be stated whether environmental impacts are acceptable given the chosen project design, i.e. including protective measures where appropriate, and the specified evaluation criteria).

5. Recommendations for environmentally sound options

5.1 Comments on project location from the environmental viewpoint

5.2 Changes in plant technology

- Modified production ranges
- Alternative production technologies
- Alternative raw materials and fuels
- Reduced energy consumption

5.3 Environmental and safety requirements to be fulfilled by a project of the type proposed

5.3.1 Measures to reduce emissions

- Construction and operation of emission control systems: filters and other types of separators for gaseous pollutants

- Treatment plants for wastewater

- Requirements regarding utilisation of residual (waste) materials

- Treatment and incineration plants for solid wastes, landfills

- Connection to disposal systems, recycling

5.3.2 Other measures in the project context

- Reduction of problems during the construction phase

- Reforestation requirements (natural regeneration, restocking) in connection with forest management

- Recultivation measures in connection with extraction of mineral resources

- Groundwater recharging measures

- Inclusion of protective and buffer zones as well as protective forests such as green belts

- Back-up regional development planning

5.3.3 Training and awareness-raising measures for personnel with regard to occupational safety and environmental protection

5.3.4 Development of monitoring measures

- General organisation of local monitoring and advisory services
- Measurement and monitoring by the operator
- Monitoring by third parties
- Capacities of these institutions

5.3.5 Organisational arrangements to ensure that planned protective measures are implemented

1. Examination of alternative ways of achieving the project purpose, baseline state.

2. Comments on national environmental regulations and their implementation.

6. Overall assessment and decision-making aids

6.1 Are the project's impacts foreseeable and assessable?

6.2 How is the project to be rated from the environmental viewpoint?

- As having positive effects on the environment
- As having no environmental significance
- As defensible, i.e. acceptable with additional conditions imposed where necessary
- To be rejected on environmental grounds