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close this bookConducting Environmental Impact Assessment in Developing Countries (UNU, 1999, 375 pages)
close this folder3. EIA process
close this folder3.4 EIA process in tiers
close this folder3.4.1 Screening
View the document(introduction...)
View the document3.4.1.1 Illustrations of screening Illustrations of screening

Screening thresholds are generally set considering the project type, size, and location. The project type and size are used to estimate the extent of the impacts while the thresholds of the project size depend on the project type. Information on the project location is used to assess the sensitivity or fragility of the neighbourhood environment. In practice, a combination of project type, size, and location is used. Some examples of different screening models are illustrated below. Clearly, there is no screening criteria which could be considered as the "best''. The criteria depend on the context and are to be examined or updated each time new information comes in or the understanding of the impacts improves.

(i) Project type and location
In the Philippines, projects are screened based on the type of project, whether it is a heavy industry, infrastructure project or whether it is based on resource extraction (Box 3.1 below). The other criterion considered is the location of the project in sensitive areas, regardless of the type. The two aspects are therefore mutually exclusive.

(ii) Project type and size
The screening process in Indonesia is governed by the type and size of the project. The Decree of the Minister of State for the Environment No. KEP-11/MENLH/3/94, as of 19 March 1994, specifies the following activities which require an EIA before project approval. (As per the Decree of the Minister of State for the Environment Number: KEP-14/MENLH/3/1994.) (See Box 3.2, page 33.)

(iii) Screening by categorization across tiers
In the above two cases, examples of screening systems were given wherein the criteria of type, size, and location are used at the national level. Financial institutions also have specific guidelines for screening projects to ascertain whether an EIA is required or not. The system adopted by the ADB is shown in Box 3.3 as an illustration.

Box 3.1 Screening criteria adopted in the Philippines

Prescribed activities requiring an EIS in the Philippines

The EIS system in the Philippines was established by PD 1586 in June 1978. PD 1586 defines the scope of the EIS system and broadly defines environmentally critical projects (ECP) and environmentally critical areas (ECA) that are included in the EIS system. PD 2146 specifically defines ECPs and ECAs and lists the types of projects and areas covered by the EIA system.

Lists of ECPs and ECAs are shown below.

Environmentally critical projects

Projects defined as environmentally critical and requiring an EIA based on type, regardless of location.

· Heavy industries: non-ferrous metal industries, iron and steel mills, petroleum and petrochemical industries, smelting plants.

· Resource extractive industries: major mining and quarrying projects, forestry projects, fishery projects.

· Infrastructure projects: major dams, major power plants, major reclamation projects, major roads and bridges.

Environmentally critical areas

Projects that require a project description but may require an EIA are those located in environmentally critical areas, regardless of type. (The concept of "project description" in the Philippines is similar to an IEE.)

Environmentally critical areas are:

· national parks, watershed reserves, wildlife reserves, and sanctuaries;
· potential tourist spots;
· habitat for any endangered or threatened species of indigenous Philippine wildlife (flora and fauna);
· areas of unique historical, archaeological, or scientific interest;
· areas traditionally occupied by cultural communities or tribes;
· areas frequently visited and/or hard-hit by natural calamities;
· areas with critical slopes;
· prime agricultural lands;
· recharge areas of aquifers;
· water bodies

The categorization by the ADB of each proposed programme or project is made according to its type, location, sensitivity, scale, the nature and magnitude of its potential impact, and the availability of cost-effective mitigation measures. The screening method is thus linked to the other tiers of the process of EIA. The screening process in the ADB not only tells "whether an EIA is required: but also what level of EIA is required.''

Box 3.2 Screening threshold for EIA in Indonesia


Type of activity



Mining and energy sector

1. Mining area during exploitation phase, for production of:

³ 200 ha and/or

· coal

³ 200,000 ton per year

· primary ores

³ 60,000 ton per year

· secondary ores

³ 100,000 ton per year

· non-metallic minerals, sand and gravel (Golongan C), radioactive materials, including mining, processing, and purification

³ 300,000 m3 per year

2. Transmission lines

³ 150 kV

3. Electricity generating stations: diesel, gas, steam, and combined cycle

³ 100 MW

4. Hydroelectric generating stations of all types and sizes, except mini-hydro and direct current types

5. Geothermal electricity generating stations

³ 55 MW

6. Other types of electricity generating stations

³ 5 MW

7. Oil and gas exploitation

8. Oil and gas processing (refinery)

9. Oil and gas pipelines

³ 25 km


Health sector

1. Class A hospitals producing basic drug materials

2. Other hospitals which are equivalent to Class A or Class I

3. Other hospitals

³ 400 beds

4. Hospitals with full/comprehensive specialist services

5. Pharmaceutical industry facilities producing basic drug materials


Public works sector

1. Construction of dams and embankments

height ³ 15 m or impounded area ³ 100 ha

2. Irrigation area development

irrigated area ³ 2000 ha

3. Tidal swamp area development

area ³ 5000 ha

4. Coastal protection in large cities

population ³ 500,000

5. River improvement works in large cities

population ³ 500,000

6. Canalization/flood control facilities in large cities

population ³ 500,000

7. Canalization other than item 6 above

length ³ 5 km or

(coastal areas, swamps, etc.)

width ³ 20 m

8. Construction of toll roads and fly-overs

length ³ 25 km or width ³ 50 m

9. Highway construction

length ³ 25 km

10. Arterial and collector road construction and upgrading outside of large cities and metropolitan areas

length ³ 5 km or area ³ 5 ha

11. Garbage disposal using incineration

³ 800 ton/ha

12. Garbage disposal using controlled landfill or sanitary landfill systems

³ 800 ton/ha

13. Garbage disposal using open dumping systems

³ 80 ton/ha

14. Drainage systems using canals in large cities and metropolitan areas, primary canal length

³ 5 km

15. Wastewater treatment:

Construction of wastewater treatment facilities in urban areas

area ³ 50 ha

Construction of sewerage systems

service area ³ 2500 ha

16. Public housing and settlement construction

area ³ 200 ha

17. Urban renewal projects

area ³ 5 ha

18. Construction of multi-storied and apartment buildings

height ³ 60 m


Agricultural sector

1. Shrimp/fish culture

area ³ 50 ha

2. Development of rice fields in forested areas

area ³ 1000 ha

3. Plantations

area > 10,000 ha

4. Cash crop farms

area ³ 5000 ha


Tourism sector

1. Hotels

size ³ 200 rooms or area ³ 5 ha

2. Golf courses, recreational parks, tourism resort areas, or estates

³ 100 ha


Transmigration and forest resettlement sector

1. Proposed transmigration settlement construction

area ³ 3000 ha


Industrial sector

1. Cement (made through production of cement clinker)

2. Pulp and paper industry

3. Chemical fertilizer (synthetic)

4. Petrochemical industry

5. Steel smelting

6. Lead smelting

7. Copper smelting

8. Alumina production

9. Blended steel smelting

10. Aluminum ignot production

11. Production of metal pellet and sponge products

12. Production of pig iron

13. Production of ferro-alloys

14. Industrial estates

15. Ship building

vessels ³ 3000 DWT

16. Aircraft production

17. Integrated plywood production

18. Production of weapons, ammunitions, and explosives

19. Battery production

including associated facilities


Communications sector

1. Railway construction and associated facilities

2. Subway construction

length ³ 25 km

3. Construction of Class I, II, and III harbours and associated facilities

4. Construction of special ports

5. Coastal reclamation projects

6. Marine dredging

area ³ 25 ha

7. Port handling areas

volume ³ 100,000 m3

8. Airports and associated facilities


Trade sectors

1. Trading/shopping centres (relatively concentrated)

area ³ 5 ha or building area ³ 10,000 m2


Defence and security sector

1. Construction of ammunition storage facilities

2. Construction of naval bases

classes A, B, C

3. Construction of airforce bases

classes A, B, C, or equivalent

4. Construction of battlefield training centres/shooting ranges

area ³ 10,000 ha


Nuclear energy development sector

1. Nuclear reactor construction and operation, and energy production reactor, and research reactor

³ 100 kW

2. Construction and operation of non-reactor nuclear energy facilities

Nuclear materials fabrication

production ³ 50 fuel elements per year

Radioactive waste treatment facilities

all facilities

Radiation source materials

source ³ 1850

TBq (5000 Ci)

Radioisotope production

all facilities


Forestry sector

1. Safari park construction

³ 250 ha

2. Zoo construction

³ 100 ha

3. Forest concessions (HPH)

³ 1000 ha

4. Sago palm forest concessions

³ 1000 ha

5. Industrial forest concessions (HTI)

³ 5000 ha

6. Establishment of parks, including national parks, nature reserves, hunting preserves, marine parks, wildlife preserves, biosphere preserves

³ 5000 ha


Toxic and hazardous materials management 1 Construction of toxic and hazardous (B3) waste treatment facilities


Integrated/multisectoral activities Businesses and activities comprised of related activities in a single ecosystem type, which require an EIA individually and which are under the authority of more than one government agency

Screening systems discussed above use guidelines but do not include details of the project and the environment. A quantitative and higher order screening system based on questions and a rating system is described in Tables A and B of Box 3.4 (page 38). This system essentially "grades'' the projects into high, moderate, and low impacts and this classification could be potentially used to decide on whether EIA is required, as well as the level of EIA.