Environmental Impact Assessment — The Two Models — Environmental Law Notes

Environmental Impact Assessment — The Two Models

Imagine a dam is proposed on a river. Once built, it cannot be un-built — the drowned valley, the displaced villagers and the lost forest are gone forever. The sensible question is not “how do we clean up afterwards?” but “should this be built at all, and if so, how?” Environmental Impact Assessment (EIA) asks that question before the first stone is laid: it forces a project to study, disclose and answer for its environmental cost before it can begin. It is the law’s way of looking before it leaps.

What is Environmental Impact Assessment?

Environmental Impact Assessment (EIA) is the process of studying a proposed project’s likely environmental effects before it is allowed to start, so that a project which will cause serious harm can be stopped, moved or modified in time. A project of the listed kinds cannot begin until it obtains prior environmental clearance on the strength of that study.

It exists because environmental damage is usually cheaper to prevent than to repair — and often impossible to repair at all. Assessing the impact in advance lets the decision-maker weigh the development against its ecological cost and attach conditions, rather than discovering the damage once it is done.

A. The two models — discretionary vs mandatory

This is the framing the exam wants, so state it as a clean contrast. The world’s EIA systems follow one of two models for deciding when an assessment is required.

The discretionary model. No fixed list. For each project, the administrative authority uses its discretion to decide, case by case, whether an EIA is needed — screening each proposal and calling for a study only if it judges the impact significant.
- Advantage: flexible — effort is spent only where the authority thinks it matters.
- Drawback: it is subjective and uncertain — different officers may decide differently, and a genuinely harmful project may slip through if the authority underestimates it.
The mandatory model. A pre-set schedule of project types (dams, mines, refineries, ports, large industry) for which an EIA is compulsory by law. If a project falls within the schedule, it must undergo assessment — no discretion to skip it.
- Advantage: certain, transparent and uniform — everyone knows in advance which projects need clearance.
- Drawback: it can be rigid, and a harmful project just outside the list may escape.

India follows the mandatory model. The EIA Notification lists categories of projects that compulsorily require prior clearance, rather than leaving it to an officer’s discretion in each case — though, as you will see, the 2006 scheme adds an element of screening for the smaller (Category B) projects.

B. The EIA Notifications — 1994 and 2006

The mandatory scheme was put in place by delegated legislation under the EPA.

EIA Notification, 1994 — the first, issued under EPA s. 3; it made environmental clearance compulsory for a schedule of projects listed in it.
EIA Notification, 2006 — replaced the 1994 Notification and restructured everything into two categories:
1. Category “A” — larger / more sensitive projects, appraised at the Central level by the Ministry (MoEF) on the recommendation of an Expert Appraisal Committee (EAC); clearance here is mandatory.
2. Category “B” — smaller projects, appraised at the State level by the State Environment Impact Assessment Authority (SEIAA) on the recommendation of a State Expert Appraisal Committee (SEAC); these are further screened into B1 (needs a full EIA study) and B2 (does not) — this is where a discretionary, case-by-case screening element enters India’s otherwise mandatory scheme.

C. The stages of the process

For Category A and B1 projects the process runs in four stages — a ready-made list for the answer:

Screening — deciding whether the project needs a full EIA study at all (relevant to Category B, to sort B1 from B2).
Scoping — the appraisal committee fixes the Terms of Reference (ToR): the environmental concerns the EIA study must address.
Public Consultation — a public hearing at which local people affected by the project, and other stakeholders, give their views in writing; their concerns must be addressed.
Appraisal — the committee examines the final EIA report and the outcome of consultation and recommends grant or refusal of clearance, with conditions.

💡 EXAM TIP — the two models are the mark-scoring core

The trap. Most candidates describe only the Indian clearance procedure and never name the “two models” the question actually asks about — losing half the marks.

What to write. Open by contrasting the discretionary model (authority decides case by case; flexible but subjective) with the mandatory model (a fixed schedule; certain but rigid), then say India follows the mandatory model under the EIA Notification, and only then outline the four stages (screening, scoping, public consultation, appraisal).

Why it scores. The examiner is testing whether you know the conceptual distinction, not just the Indian steps — leading with it shows you answered the question set.

🧩 WORKED EXAMPLE — placing a project in the scheme

Facts. A company proposes a large thermal power plant near a river.

Rule. Under the mandatory model of the EIA Notification 2006, a listed project needs prior environmental clearance; a large/sensitive project is Category A, appraised centrally by the MoEF on the EAC’s recommendation, through screening, scoping, public consultation and appraisal.

Apply. A large thermal plant is a scheduled, Category A project, so an EIA is compulsory — the company cannot skip it. It must obtain ToR at scoping, prepare the EIA report, face a public hearing of the affected villagers, and secure the MoEF’s clearance (with conditions) before any construction begins.

Conclusion. Because India uses the mandatory model, the plant’s assessment is not left to an officer’s discretion — it is required by the schedule, which is exactly the certainty the mandatory model is designed to give.

flowchart TD
    ROOT["EIA<br/>(clearance before a project starts)"]:::root
    ROOT --> M["Two models"]:::leaf
    M --> M1["Discretionary:<br/>authority decides case by case<br/>(flexible, subjective)"]:::diamond
    M --> M2["Mandatory:<br/>fixed schedule of projects<br/>(certain, uniform) — India"]:::leaf
    ROOT --> N["EIA Notification 2006"]:::leaf
    N --> N1["Category A: central (MoEF + EAC)"]:::leaf
    N --> N2["Category B: state (SEIAA + SEAC)<br/>B1 needs EIA / B2 not"]:::leaf
    ROOT --> S["Stages: screening &rarr; scoping &rarr;<br/>public consultation &rarr; appraisal"]:::leaf
    classDef root fill:#FFF8DC,stroke:#000,stroke-width:1px,color:#000;
    classDef leaf fill:#E6F3FF,stroke:#1E3A8A,color:#000;
    classDef diamond fill:#FDECEA,stroke:#B22222,color:#000;
    linkStyle default stroke:#888,stroke-width:1px;

Case Laws

Lafarge Umiam Mining Pvt. Ltd. vs Union of India (2011) — the Supreme Court laid down principles for granting environmental clearance and stressed that the EIA and clearance process must be followed strictly and in good faith.
Narmada Bachao Andolan vs Union of India (2000) — the Court examined the conditions attached to a major dam’s environmental clearance, illustrating that clearance is granted subject to environmental safeguards.
Indian Council for Enviro-Legal Action vs Union of India (1996) — underlined that preventing environmental harm in advance (the precautionary approach behind EIA) is central to India’s environmental law.

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