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close this bookConducting Environmental Impact Assessment in Developing Countries (UNU, 1999, 375 pages)
close this folder4. EIA methods
close this folder4.2.1 Descriptive checklists
View the document(introduction...)
View the document4.2.2 Weighted-scale checklists
View the document4.2.3 Advantages of the checklist method
View the document4.2.4 Limitations of the checklist method

4.2.2 Weighted-scale checklists

Weighted-scale checklists are used to:

· recognize the relative differences between the importance of environmental issues;

· allow for scoring and aggregation of impacts arising from the issues on the environmental components; and

· permit a quantitative comparison between alternatives.

Box 4.2 Environmentally significant issues for a power development project

· Expropriation of land which negatively affects aquatic habitat for biota, aquaculture, fishing, recreation, domestic/industrial water use, irrigation, recreation, water transportation.

· Construction activities of facilities and transmission corridors which negatively affect aquatic habitat, water quality, aquaculture, domestic/industrial water use, recreation due to chemical contamination, shoreline changes (e.g., riparian vegetation removal, retaining walls, diking), and sedimentation.

· Effects of discharge of SO2 NOx, TSP (total suspended particles) on air quality.

· Noise and flying rock from blasting and drilling operations.

· Increased ship traffic for coal transport.

· Effects of noise from boiler operation, gas turbines, and cooling towers on livestock.

· Social problems associated with integration of migrant construction workers with local community.

· Use of herbicides for maintenance of transmission corridors can negatively affect surface and groundwater quality.

· Disruption of crop farming by construction of transmission lines.

· Effects of SO2 emissions on crop farming.

· Loss of forest area due to construction of transmission lines.

· Illegal logging from access roads for power developments.

· Effects of transmission line networks on animal and plant diversity.

· Effects of thermal discharge on aquatic ecosystem.

· Disposal and indiscriminate dumping of construction waste materials.

· Effects of channel dredging for ship traffic on aquatic habitat.

· Effects of earthworks on dust production.

· Emergency and disaster response (e.g., forest fire, earthquake) at power plants.

· Dams and impoundments in rivers cause major changes to riverine ecosystems, which can significantly affect water quality, habitat for aquatic biota, aquatic resources harvesting (e.g., fishing, aquaculture), recreation, domestic/industrial water use, water transportation, local water table levels and groundwater flow.

· Regulated flows and lake (impoundment) levels which affect habitat for aquatic and terrestrial biota, fishing, navigation, recreation, domestic/industrial water use.

· Impounded water provides habitat for vectors that carry disease.

· Effects of cooling water withdrawal (entrainment and impingement) for power plants on aquatic life.

· Effects of fuel storage on dust and safety of employees and local community.

· Risk of spills or accidents associated with fuel transport.

· Fate and effects of leachates of disposed sludge in landfills.

· Effects of groundwater and surface water consumption (pumping) on water supply and local ecosystems.

· Treatment and disposal of sewage generated at the power plant site

Box 4.3 Checklist for environmental effects commonly associated with projects in fisheries and aquaculture

Fisheries projects (capture of species) and aquaculture projects for growing selected species often involve the entire gamut of potential adverse environmental impacts, including impacts on natural resources, economic development values, and quality-of-life values.

A Environmental problems related to site selection (which might be avoided or minimized by better site selection)

1. Conflicts with other site (waterway) uses. Such other uses may be the use of the same water area for tourism/recreation and navigation, and for creating more agricultural land by filling the area.

2. Hazards of serious pollution. Sites should preferably be upstream of pollution-emitting facilities (such as oil refineries). Single slug discharges can raise havoc with entire fishery/aquaculture (F/A) operations. If pollution hazards do exist, the F/A plan should ensure careful emissions control.

3. Remoteness from market requires freezer storage.

4. For aquaculture, steady availability of freshwater supply. Need to ensure year-round availability of supply which is basic for project economics. For dam/reservoir releases, this may conflict with other water use allocations in drought periods. If water is drawn from irrigation canals, canal O&M plan must enable steady delivery of water (not complete shutdown of delivery when cleaning/repairing canals).

5. For aquaculture, costs for importing needed foods.

6. Water quality and quantity. Water quality (WQ) suited to the project's needs is basic for F/A operations. This includes, for fisheries, impacts on WQ likely to result from pollution inflows, changes in local hydrology from probable upstream dams or other river development, and possible seawater influx during storms.

7. Hurricane and typhoon hazards. Facility design must consider these hazards (for example, the aquaculture facilities in Laguna Lake near Manila are designed to minimize this problem).

8. Labour supply problem including skilled labour needs.

9. Local soil properties. For aquaculture projects, the local soils may not be suitable for furnishing structural stability for berms made from the soil, and may be excessively permeable, and moreover some soils can adversely affect water quality. See item (6).

10. Resettlement.

11. Availability of species juvenile stock.

12. Peripheral development hazard. This concerns the effects of F/A waterbody region, including destruction of mangroves on which the project may be critically dependent for food.

13. Site filling hazards. This is the hazard when accelerating erosion in the upstream watershed reduces the volume of the water body used for the F/A operations.

14. Security from poachers. Poaching, either by outsiders or by insiders, can ruin the project economics. In some cases, it may be desirable to organize the overall operations into a series of sections of a size suited to operation and control by a single family management.

B Environmental hazards relating to inadequate design

1. Item (A) (1) to (12). Design omissions on items (A) (1) to (12) involve the same problems as noted under (A). Design expertise is needed to minimize/offset unavoidable adverse effects due to project location.

2. Unrealistic O&M assumptions. Such unrealistic assumptions on the available quality of O&M can greatly undermine and negate the project economics and result in serious adverse environmental impacts in a variety of ways, including many of those described in (A).

3. Inattention to special construction requirements. Customary types of plans and specifications must be modified to provide for incorporation of the environmental protection parameter into the plans/specifications and for construction stage environmental monitoring. It may involve periodic checks on the actual environmental impact of the project following completion of construction vis-a-vis those projected at the time of project appraisal.

4. Salability of product. For both F/A projects, an important criterion for economic viability is the presence of a suitable market for the product and the capture or raising of species which will be favoured by the intended customers.

5. Middlemen problems. One of the socio-economic problems commonly involved in protecting F/A is the advent, during the operations phase, of immigrants who take over the middleman's role, buying the fish from the fisherman for re-sale. Without any control, this practice can reduce the fisherman's earnings to unfair and unacceptably low levels.

6. Dredging and filling. These activities must be carefully planned so as not to destroy precious ecology.

7. Disease hazards. Planning of an aquaculture venture must give attention to fishery disease hazards, which can drastically reduce yields. The selection of species has to be appropriate from the point of view of previous aquaculture disease hazards in the area and the availability of feasible control methods.

8. Socio-economics. In addition to item (5), it is necessary to favour local population labour needs, especially those resettled by the project, and families of fishermen in the vicinity whose livelihoods will be impaired by the project, rather than imported labour (to become permanent new residents).

9. Downstream water quality. Discharges from aquaculture projects (especially those with high rates of productivity employing special aeration and feeding techniques) may need to be treated (by ponding) to prevent downstream WQ and beneficial uses.

10. New species hazards. Care must be exercised in introducing new species for aquaculture, i.e., to assess the impacts on existing fishery species distribution in the area and region.

11. Permit system. A competent management system should be established to manage the new F/A to ensure the proper selection of fishing rights by fisherman, financial assistance to enable them to get started, for preventing over fishing and illegal fishing methods, for assistance in controlling middlemen (item [5]), and assistance in marketing based on the use of an appropriate fee system for recovering costs.

12. Fishing village sanitation. Proper planning and administration (see item [11]) and guidance in the establishment/growth of fishing villages in the project vicinity should be provided to ensure that these do not turn into "sanitation messes" that pollute the F/A waterbody and threaten public health.

C Environmental hazards related to construction stage

1. For F/A projects, common construction hazards for the environment include: (1) dredging/filling of ecologically sensitive areas; (2) discharge of silt which diffuses and permeates sensitive areas and/or recreation beaches in the vicinity; and (3) interference with navigation (including fishermen's travel) including silt deposition into navigation channels.

D Environmental problems relating to operations stage

1. O&M capabilities. A common problem in many developing countries is the failure to furnish the O&M specified in the design, even when the design specifications are realistic, appropriate, and affordable.

2. Monitoring. Another common problem is the failure to implement continuing periodic post-construction environmental monitoring as specified in the project feasibility and/or EIA. Thus, inadequacies in design assumptions and/or O&M may not be detected. Such feedback is essential for delineating and implementing corrective measures needed for acceptable environmental protection.

E Critical environmental review criteria

These are criteria of special interest to an environmentalist which should be applied to all major infrastructure or regional development planning projects.

1. Will the project cause unwarranted losses in precious/irreplaceable natural or other resources?

2. Will the project make an unwarranted accelerated use of scarce resources in favour of short-term rather than long-term economic needs?

3. Will the project result in unwarranted hazards to endangered species?

4. Will the project tend to intensify undesirable migration from rural to urban sectors to an unwarranted degree?

5. Will the project adversely depreciate the national energy/foreign exchange situation to an unwarranted degree? Will there be intensification of national socio-economic imbalances due to increase in affluent/poor income gap?

Source: Asian Development Bank

The use of weighted-scale checklists thus encompasses IEE. One such weighted-scale checklist referred to in the literature is the Environmental Evaluation System (EES) (developed by the Battelle Columbus Laboratories, USA). EES was developed in 1973 to address water resource development projects. Because environmental properties are not commonly measured in similar units, it is difficult to evaluate the net environmental effects of a project and to make trade-offs in selecting among alternatives. EES attempts to solve this problem by transforming all parameters into similar units.

EES provides for environmental impact evaluation in four major categories: ecology, environmental pollution, esthetics, and human interest. These four categories are further broken down into 18 environmental components and finally into 78 environmental parameters. For each parameter, a value function is developed using a Delphi technique which would translate the sensitivity or scale of the parameter into equivalent environmental impact units (EIUs). To allow a correct aggregation of EIUs across the components and categories, each parameter is set an importance known as a parameter importance unit (PIU). PIUs thus provide weights for the purpose of aggregation. Results of using the EES include a total weighted score in EIU with and without the proposed project; the difference between the two scores is one measure of environmental impact.

The EES technique consists of three steps. Step 1 involves transforming parameter estimates into EIUs. In the evaluation system, environmental quality is defined in the following fashion. It is a value between 0 and 1, where 0 denotes extremely bad and 1 denotes very good quality. The transformation of a parameter estimate into environmental quality is achieved through the use of a value function relating the various levels of parameter estimates to the appropriate levels of environmental quality.

Step 2 consists of the weighing of parameters. Each parameter used in the EES represents only a part of the total environment. It is therefore important to view these parts together as part of the environmental system. To reflect the relative importance of the EES parameters, a total of 1000 points or PIU are distributed among the parameters. Sociopsychological scaling techniques and the Delphi procedure were used to quantify the value judgments. The process consisted of ranked pairwise comparisons and controlled feedback.

In step 3 EES is used to evaluate the expected future condition of environmental quality without the project, and with the project. The former evaluation is an expression of the modified current condition of the environment, whereas the latter is an expected (predicted) condition of the environment with the proposed development. A difference in EIUs between these two conditions constitutes either an adverse (loss in EIU) or a beneficial (gain in EIU) impact.