13 EIA Methodology

Sunil Mittal

1. Introduction

1.1 Desirable of EIA methodologies

1.2 Criteria for selection of EIA Methodology

1.3 Choosing a Method

1.4 Objectives of methodologies

1.5 Focus of Methodology

1.6 Methodology Requirements

2. Major Methodologies of EIA

2.1 Ad Hoc

2.2 Checklists

2.3 Matrices

2.4 Networks

2.5 Overlays

1. Introduction

EIA methodology is a structural approach developed to identify, predict and value changes of an action. Changes are reflected to the sequence of activities, steps regarding the environmental issues (physical, chemical, biological, socioeconomic, cultural, landscape values and processes). The methodology uses in process quantify these changes. 1.1.

1.1. Desirable of EIA methodologies

EIA Methodology are based on principle of equality, openness, cost-effectiveness and efficiency approaches. Broadly these are 4 types.

(a) Comprehensive: Recognize intricate systems and bound complex inter-relationship.

(b) Selective: Pinpoint critical (significant) impacts and eliminate as early as possible unimportant impacts.

(c) Comparative: Determine environmental changes due to the project activities compared with under existing conditions (Before starting project).

(d) Objective: Provide unbiased measurements free from political and external influences.

1.2. Criteria for selection of EIA Methodology

Simplicity: The methodology should be simple and based on available manpower & background knowledge. It can be adapted without much difficulty.

Budget and Time: The methodology should be applied by small group with under approve budget and limited time span.

Flexibility: The method should be flexible and allow the modifications and changes during course of study.

1.3. Choosing a Method

The methodology of EIA ranges from simple to complex and requires different kinds of data, several data formats, expertise and technological skill for their interpretation. Their analyses produce differing levels of precision and certainty. All of these factors should be considered for selecting a suitable methodology.

1.4. Objectives of methodologies:

1. Understand the nature and location of the project and possible alternatives

2. Identify factors of analysis and assessment objectives

3. Preliminary identification of impacts and scoping

4. Baseline studies and evolution in the absence of projects

5. Prediction and assessment of impacts and alternatives comparison

6. Mitigation

7. Monitoring and impacts management

1.5. Focus of Methodology

Potential impacts and their types of environmental components Natural and social systems Time and space

1.6. Methodology Requirements

The EIA practitioner faces vast varieties of raw and unorganized information that must be collected and analyzed in preparation of an EIA report. The best methods are able to:

Organize a large mass of heterogeneous data Allow summarization of data
Aggregate the data into smaller sets with least loss of information
Display the raw data and the derived information in a direct and relevant fashion
Target audience should also be considered (example if target audience are not educated then, use of color code, size, cross etc. should be used rather that figures and tables)

2. Major Methodologies for EIA

Following are the 5 major methodologies of EIA.

a) Ad Hoc

b) Checklists

c) Matrices

d) Networks

e) Overlays

a) Ad Hoc Method: This is a simple method and based upon broad environmental impacts aspects. This method is very useful whenever time period is limited with lack of require scientific information. In such situation, EIA depends exclusively on background, expertise and experience of experts. This method is not recommended, when more scientific methods are available.

Types of Ad Hoc Method

Opinion polls
Expert opinion
Delphi methods etc.

Advantage:

Simple and easily understandable.
The experts of a respective areas guide EIA.
Overall environmental components are enlisted.

Disadvantage:

It required expert person.
The identification and prediction of short & long term impacts are poor because it examined on guess basis.
It provides minimal guidance for impact analysis, while suggesting subjective area of impacts
Not good for organizing, reviewing and interpreting data

b) Checklists:

Checklists are standard lists of the types of environmental potential impacts, which may be associated with respective project. The lists are prepared with highly structured approaches and involve importance with weighing of factors and ensure that no potential impact is overlooked. Checklists are very effective in impact identification and capable to spread awareness & attention for respective people.

Checklists should enable identification of impacts on Soil, Water, Atmosphere, Flora, Fauna, Resources, Recreation and Cultural etc. status.

A typical checklist might contain entries such as:

Earth: Mineral Resources, Construction Material, Soils, Land form, Force fields and Background Radiation, Unique physical features
Water: Surface water like rivers, lakes and reservoirs, estuaries, coastal seas and ocean, Groundwater quality, Snow, Ice
Atmosphere: Quality regarding gases & particles), Climate, Temperature
Flora: Trees, Shrubs, Grass, Crops, Micro & Macro flora, aquatic plants; endangered species; barriers; corridors
Fauna: birds; land animals including reptiles; fish and shellfish; benthic organisms; insects; micro fauna; endangered species; barriers; corridors
Land Use: Wilderness and open space, Wetlands, Forestry; Grazing, Agriculture, Residential, Commercial, Industrial, Mining and Quarrying
Recreation: Hunting; Fishing; Boating, Swimming, Camping and Hiking, Picnicking,Resorts

Types of Checklists

(i) Simple Checklist

(ii) Descriptive Checklists

(iii)Scaling Checklist

(iv) Scaling Weighting Checklist

(v) Questionnaire Checklist

(i) Simple Checklist

Simple checklist consist simple list of environmental parameters and no information needed on the magnitude or importance of impacts.Checklist can recognize resource/environmental component, which affects by particular activities.

The example given below (Table 1) for construction sites, the tick mark confirm that impact is there, where no tick mark or leaving the box means no impact.

(Source http://ec.europa.eu/environment/archives/eia/eia-studies) Table 2: Checklist Used for Identifying Impacts of the Turku Central Sewage

Treatment Works

	Impacts on environment			Impacts on built
					environment
	Soils and	Surface and	Air and	Flora	Urban	Buildings	Landscape	Cultural
	Geology	groundwater	climate	and	structure and	and	and	heritage
				fauna	planned land	structures	townscape
					use

Construction
Ground
preparation work
Surface structures

Operation
Treatment of waste
Water
Intake and removal
of air
Treatment of sludge

Transport
traffic

Exceptional
circumstances
disturbances in
operation

(Source http://ec.europa.eu/environment/archives/eia/eia-studies)

Mark indicates issues the project and have an impact. The lack of the symbol indicates that the impact will not occur or insignificant.)

Simple Checklist can also give idea about type of impacts like short term, long term, reversible, irreversible etc. An example is depicted in Table 2, mentioned checklist used to identify impacts of Turku Central Sewage Treatment Works. Ground preparation work, waste water treatment, treatment of sludge, traffic and disturbances in operation has impact on air& climate and resulting in a cumulative impact.

(ii) Descriptive checklist

Descriptive checklist is extension of simple checklists and adds background information of each aspect. It also includes guidelines on the measurement of parameters.Simple checklist consist only aspects, whereas descriptive checklist give both aspect and their background information.

Descriptive checklists are strong for impact identification of environmental parameters and also incorporate to measurement of impact measurements, interpretation &evaluation of impacts as well as in decision making process. It guides mainly how to impacts assess and include data requirements, information sources and predicted techniques as in Table 3.

Descriptive checklist delivers more information about the nature and magnitude of the impacts rather than just identification, whether it occurs or not. Table 4 is an example of a descriptive checklist and includes past, present and future actions.The checklist can also discuss the cumulative impacts due to past activities, project and other nearby sources.

(iii) Scaling Checklist

Scaling checklists are similar to the descriptive checklist with additional information of subjective scaling of the impacts on the environmental parameters.

The meaning of scaling is rating or grading system. Example: The rating of Water Quality, i.e. best is 5 and 1 for worst. In case of school, generally follows A+, A, B+, C etc. A representative example is given below for scaling of parameters in Table 5:

(iv) Scaling Weighting Checklist

Scaling Weighting Checklist represent scaling checklists with information provides as to subjective evaluation of each parameter with respect to every other parameter. Scaling weighting checklists employ both magnitude and importance factor.

In this checklist method, give weightage to specific parameter on the scale and evaluate the Parameter Importance Value for the environmental components and parameters. The structured equations are used to weigh of the environmental parameters. Weighting means give importance to some specific parameter, example water quality is prime important in one project in comparison to land area. So with scaling, give weight to water parameter, so it becomes more important in evaluation.

Example: Environment Evaluation Value System such as Battelle Environment Evaluation System.

The Environmental Evaluation System (EES) is a methodology, which conducts environmental impact analysis.The EES evaluates environmental impact in four major categories such as ecology, environmental pollution, esthetics and human interest.

Major features of the EES are:

1. Its hierarchical classification system;

2. Its commensurate unit of measure (EIU)

3. Its flaging of environmentally sensitive areas.

Battelle Environment Evaluation

The Battelle Environmental Evaluation System (EES) is a methodology that developed by Battelle Columbus Laboratories for conducting environmental impact analysis (Dee et al., 1972 &1973).It is based on a hierarchical assessment of environmental quality indicators.

The system is based on a classification consisting of four levels:

The system is based on classification consisting of four levels. Category (Level 1) is divided into several components (Level II) and each component is divided into several parameters (Level III) and further parameters divide into several measurements (Table 6).

Level I: Categories (4)

Level II: Components (18)

Level III: Parameters (78)

Level IV: Measurements

The two EIU scores are produced with and without project activities. The difference between them gives measurement of the environmental impact. Suppose a scale of 10, the score is 8 before starting a project and it became 3 after completion of project, then measurement of impact is 5, means have a lot of impact. If difference will come 2, means less impact.

Table 6 shows the complete list of categories, components, and parameters of the Battelle EES. Column 1 shows the four (4) categories, Column 2 shows the eighteen (18) components and Column 3 shows the seventy-eight (78) parameters.

The EES methodology depends upon the assignment of an importance unit to each parameter and collectively these “importance units” are referred to as “parameter importance units” or PIU’s. A total of 1000 PIU’s is distributed among the 78 parameters based on value judgments. The individual PIU’s are shown in Column 4 of Table 6, the summation component PIU’s are shown in Column 5, and the summation category PIU’s are shown in Column 6. Effectively, for each parameter i, its (PIU)i represents a weight wi.

Each PIUI or wi requires a specific quantitative measurement and the methodology converts in different measurements i.e. scalar or “value function.” A scalar has the specific measurement in the x-axis and a common environmental quality scale or “value” in the y-axis. The latter varies in the range 0 ≤ Vi ≤ 1 Where Vi stands Environmental Quality (Source: Victor M. Ponce).

If Vi = 0 indicates very poor quality Vi = 1 indicates very good quality

Figure 1 shows an example of a typical scalar, that of dissolved oxygen (DO) (Table 1, Column 3, number 21). In this figure, Vi (environmental quality) varies in the range 0-1 as a function of DO concentration (mg/L).

Values of Vi = Vi, 0 are obtained for conditions ‘without’ the project and Vi = Vi, 1 for conditions ‘with’ the project

The condition ‘without’ represents the current condition of project activities in case of ‘with’ represents the predicted future condition of project.

The environmental impact EI is evaluated as follows:

EI = ∑ [Vi, 1 wi ] – ∑ [ Vi, 0 wi ]

For i = 1 to n, where n = number of parameters (78).

For EI > 0, the condition ‘with’ the project is better than ‘without’ the project, indicates project has positive environmental benefits. Reversely, EI < 0, the situation ‘with’ the project is worse than ‘without’ the project, indicating certain negative impacts& benefits.

The potential problem areas are characterized by those parameters for which the Vi value changes significantly in the adverse direction, as measured by the following relation (in percent):

ΔVi (%) = 100 (Vi, 0 – Vi, 1) / Vi, 0

These parameters are tagged with ‘red flags’ to indicate potential problems which may warrant more detailed attention.

For parameters in the ecology category, a minor red flag applies

When 5% < ΔVi < 10%; a major red flag, when ΔVi > 10 %

For all other categories, a minor red flag applies when ΔVi < 30%, or ΔVi < 0.1 (in absolute value, per unit);

A major red flag when ΔVi ≥ 30%, or ΔVi ≥ 0.1 (in absolute value, per unit).

(v) Questionnaire Checklist

The checklist is prepared on the basis of questions for Public Consultation (Table 7). It gives information about the stakeholder’s awareness and responses for their proposed project.The questionnaire is further evaluated in spread sheets to find the scale of impacts and weight of parameters based on public opinion.

Advantages

§ Simple to understand and use

§ Good for site selection and priority setting

§ Impacts can see on past, present & future

Disadvantages

§ Do not distinguish between direct and indirect impacts.

§ Do not link action and impact.

§ Sometime it is a cumbersome task.

2.3 Matrix

Matrix method provides a framework forinteraction between project activities and their environmental impacts. It can evaluate degree of impacts of project activities on environmental resources. It is a grid like table that one axis displayed project activities and other axis displayed environmental characteristics. It can also evaluate the cumulative and indirect impacts as well as interaction with resources.

Observed as two-dimensional checklist:

Axis of actions
Axis of environmental components

The intersections are the impacts

Functions:

Preliminary identification of impacts (scoping)
Comparative analysis of alternatives
Impact assessment
Presentation of evaluation results

Leopold Matrix

The Leopard Matrix provides a framework for the analysis and numerical weighting of probable impacts. It is a simple way to summarize & rank environmental impacts and to focus on that impact, which is considered to be greatest. Matrix method is pioneered by Leopold et al (1971), enlisted about 100 project actions and 88 environmental characteristic or parameter. It delivers a total of 8,800 interactions. Each action and their impact potential are considered.

The magnitude of the interaction (extensiveness or scale) is described by assigning a value ranging from 1 (for small magnitudes) to 10 (for large magnitudes). The assignment of numerical values is based on an evaluation of available facts and data. Similarly, the scale of importance also ranges from 1 (very low interaction) to 10 (very important interaction).

The impact associated with the project action columns and their environmental condition row is described in terms of its magnitude (M) and significance (I) (Figure 3).

Each impact is described by two factors:

1. Significance: Indicates the theoretical importance of the impact (eg. The spatial extension) and Varies between -10 and 10

2. Magnitude (size or importance): how much the impact is present in this case? It varies between -10 and 10

Each individual impact is estimated by the product of significance and magnitude.

In Leopard matrix: On horizontal axis – The actions cause environmental impact

On the vertical axis – The existing environmental conditions affected by actions

Table 8 depicted the factors listed in the vertical & horizontal axis of the Leopold matrix. The horizontal axis shows most efficient way to check each significant action (listed on the horizontal axis). As on listed on vertical axis give information about that each checked action (on horizontal axis) is evaluated in terms of magnitude of effect on environmental characteristics and conditions.

Matrices advantages:

Visually describe relationship between two sets of factors,

Expanded or contracted to meet needs of the proposal being assessed,

Identify impacts of different phases of project, construction, operation and so on. Help separate site-specific impacts from impacts affecting region

However, matrices also have their disadvantages: they do not explicitly represent spatial or temporal considerations and they do not adequately address synergistic impacts.

2.4 Networks

Network method identifies the pathway of an impact using a series of chains (networks) between a proposed action and the receptor of an impact. It attempt to recognize a series of impacts that may be triggered by a project action.

According to Larry et al. “Networks” are those methodologies which integrate impact causes and consequences through identifying interrelationships between casual actions and the impacted environmental factors, including those representing secondary and tertiary effects (Larry W. Canter, 1996, page 81).

The Networks or Systematic Sequential Approach (SSA) of assessment is required, a “scientific thinking through” of the potential impacts on the environment with and without the project. SSA describes how environmental, social, and economic systems are associated with each other, and how it will react to human disturbances.SSA views EIA as a continuing source of information throughout the project cycle.

Network diagrams, flowcharts and impacts trees are the effective major to analysis of the inter-relationship between causes and effects and enable the analysis of indirect and cumulative impacts. A typical figure of flow diagram is depicted as in Figure 4).

Advantages & Disadvantages of Networks Method

Advantages:

Integrated assessment, instead of discipline bydiscipline
Inter-relations between causes and effects, includingindirect impacts Cumulative impact assessment
Communication (when simple).

Disadvantages:

Complexity (especially visually complex)
Difficult to distinguish and quantify magnitudes (andimportance) of different impacts

Cause and Effect Relationship Network Diagram

The Figure 4 depicted the direct and indirect effect of fertilizer on environment. The application of fertilizer first increases the nitrogen and phosphorus in the soil. The some fraction of fertilizer reaches to run-off and become available to plants, algae and other organisms. Due to this, increase of growth and biomass in water body and resultant reduces dissolve oxygen. Reduce dissolve oxygen decrease fish populations, size and quality.

2.5 Overlay Method

The overlay method is developed by Shopley and Fuggle (1984) and McHarg (1969). It is based upon a set of transparent maps. Each represents the spatial distribution of an environmental characteristic. The set of transparent maps have information about physical, social, ecological, aesthetic characteristics of the project area and after overlapping to produce a composite characterization of the regional environment (Figure 5).

Overlay mapping is a simple technique to display of impact areas
Intensity of impacts can be presented by color shading
Effective visual aid
Useful for documentation of environmental conditions before and after project implementation
May describe both biophysical and social aspects of area under study Highly communicative
Easy to integrate multiple information (Including those of remote sensing)

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References
Dee, N., J. Baker, N. Drobny, K. Duke and D. Fahringer. 1972. Environmental evaluation system for water resource planning (to Bureau of Reclamation, U.S. Department of Interior). Battelle Columbus Laboratory, Columbus, Ohio, January, 188 pages.
Dee, N., J. Baker, N. Drobny, K. Duke, I. Whitman, and D. Fahringer. 1973. An environmental evaluation system for water resource planning. Water Resources Research, Vol. 9, No. 3, June, 523-535.
Glasson, J., Therivel, R., & Chadwick, A. (2013). Introduction to environmental impact assessment.Routledge.
Leopold, L. B., F. E. Clarke, B. B. Hanshaw, and J. E. Balsley. 1971. A procedure for evaluating environmental impact. U.S. Geological Survey Circular 645, Washington, D.C.
Partidário e Jesus, 2003.Fundamentos de AvaliaçãodoImpacteAmbiental. UniversidadeAberta.

Web links

http://www.doe.ir
http://www.ilnaturalista.it/la
https://ponce.sdsu.edu/the_battelle_ees.html
http://ec.europa.eu/environment/archives/eia/eia-studies