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ENVIRONMENTAL ASSESSMENT
Dr John Williams: Tel. 2404: e-mail: [email protected]
Environmental assessment (EA) is a systematic process, using the best
practicable techniques and best available sources of information, to assess
the environmental effects of a project. It is prepared by the developer, usually
in consultation with others, and is considered by a statutory authority in
forming its judgement as to whether, on environmental grounds, a
development project should proceed.
DEVELOPMENT OF EA LEGISLATION
Environmental assessment was accepted in principle at the UN Conference
on the Human Environment at Stockholm in 1972. This stimulated European
Legislation based on environmental action plans to enforce the consideration
of the pollution and nuisance aspects of development projects before
construction. This resulted in the Environmental Assessment Directive
85/337/EEC. The directive describes the procedures for environmental
assessment of major projects. However, it does not ensure or require
Member States to refuse to approve projects that are damaging to the
environment, just that the effects of the projects are 'taken in to consideration
during the development consent procedure'.
Assessment, as defined in the directive, consists of 5 obligatory steps;
i) the supply of information on environmental effects by the developer.
ii) consultation with other environmental agencies.
iii) consultation with the public.
iv) consultation with other Member States where the projects has
transnational implications
v) the requirement on the part of the competent authority to take into
consideration information gathered during the previous steps before making
its decision to authorise the project.
The directive lists projects under 2 categories (Annex I and Annex II) which
either (I) require a EA in every circumstance or (II) an EA is required only in
certain circumstances.
UNITED KINGDOM LEGISLATION
The UK has implemented Directive 85/337/EEC through 15 basic sets of
different regulations, plus a number of amending regulations and associated
measures. The majority of the projects are covered under the planning
regulations. However, certain project classes, and project categories and subcategories, are covered by other regulations (e.g. afforestation, major roads).
Provisions contained within the Planning and Compensation Act 1991 allow
the extension of EA to projects other than those listed in Directive
85/337/EEC. In 1994, the government used these powers to add privately
financed toll roads to the list of projects requiring EA in every case; the
following projects were added to the list for which EA is required where the
proposed development is likely to have significant effects on the environment:
windfarms, coast protection works and motorway service areas. A number of
changes were also made to the procedures. These include a requirement that
any new information supplied by the developer to supplement the
environmental statement must be subjected to the same publicity and
consultation arrangements as the original statement. The great majority of the
EAs are undertaken under the following regulations:
Town and Country Planning (Assessment of Environmental Effects)
Regulations 1988 (SI No. 1199) as amended.
Environmental Assessment (Scotland) Regulations 1988 (SI No. 1221).
Land Drainage Improvement Works (Assessment of Environmental Effects)
Regulations 1988 (SI No. 1217).
Highways (Assessment of Environmental Effects) Regulations 1988 (SI No.
1241) as amended.
The Electricity and Pipe-line Works (Assessment of Environmental Effects)
Regulations 1990 (SI No. 442).
The Environmental Assessment (Afforestation) Regulations 1988 (SI No
1207).
STAGES OF EA
An EA includes several stages not just the preparation of an environmental
statement. The stages include:
1. Screening, to decide on which projects should be subject to environmental
assessment. Criteria used include threshold, size of project and sensitivity of
the environment.
2. Scoping, defines the key issues which should be addressed.
3. Environmental Statement preparation, this contains the objective and
scientific analysis of the scale, significance and importance of the identified
impacts.
4. Review, as environmental assessments are usually carried out by the
project proponent, the studies are often reviewed by an agency or panel who
guide the study and advise decision makers.
PROJECT SCREENING PROCEDURES
Screening defines the coverage of projects for which an EA is required.
There are various procedures for identifying this, in the EC directive this is
achieved by a list in Annex 1 and 2. These were revised in 1999 to include
more projects and tighten up the decision making process.
Annex I contains projects for which an EA is always required, Annex II lists
projects for which EA is required in certain circumstances the
new
regulations sets a range of threshold values for Annex II projects. Small
developments which themselves fall below the the thresholds can still require
an EA if they add to a cumulative effect of other small projects.
New requirements are also placed on those who prepare Environmental
Assessments, such as the need to evaluate alternative project proposals and
justify the project selected on environmental grounds.
PROJECT SCOPING PROCEDURES
Scoping is the process which considers the actual or perceived problems
associated with the construction, operation and decommissioning of the
project. Many of the impacts of a proposed development may be trivial or of
no significance to the decisions which have to be taken. In practice, a
decision will generally turn upon only a small subset of issues of
overwhelming importance. Scoping is designed to identify the main issues
and those issues perceived as being of importance in the eyes of the
regulatory agencies, interested groups and the local community. (The terms
of reference or 'scope' of the assessment is decided). This sets the terms of
reference for the environmental statement. This helps the developer to
assess whether the scheme is feasible and anticipate some of the more
obvious impacts and their mitigation.
This is an important stage and requires the establishment of a team with the
appropriate depth of skills. A study of first 100 ES in the UK found that often
the poor quality of an ES could be traced back to inadequate scoping
exercises; with the result that significant environmental characteristics were
not identified and considered in adequate detail during the data collection
stage.
Scoping generally requires some combination of site visits, literature and
policy reviews, an initial data collection exercise and a first round of
consultation with interested parties. This will require the assembly of a multidisciplinary team to consider the range of issues raised.
Methods such as the Leopold Matrix are often used to give a structure to the
scoping process. The Leopold matrix needs all the actions which make up
the project to be listed at the top of a table. The Environmental Chracteristics
(such as air, water and ecology) are then placed in the first column. The
boxes on the table then are divided with a diagonal slash. In the upper lefthand corner of each box a number from 1 to 10 is assigend which indicates
the MAGNITUDE of the possible impact: 10 represents the greater magnitude
of impact and 1 the least (no zeroes). The sign before each number shows if
the impact is beneficial (+) or damaging (-). In the lower right-hand of the box
a number from 1 to 10 indicates the IMPORTANCE of the possible impact
(e.g. regional versus local); 10 represents the greatest importance and 1 the
least. This is usually accompanied with a discussion of the significant
impacvts impacts with high toal scores. The matrix can be filled in by a single
expert, a panel (then collating the results), or in consultation with interested
parties
eg. Very Small Leopold Matrix
Project Features Constructi
on
Environmental
Characteristics
4
Ecology
8
1
Air Quality
2
4
Water Quality
5
9
Total
15
Effluent
Discharg
e
Transpo
rt
Total
3
2
9
5
6
3
4
8
9
11
6
7
3
18
16
20
3
13
16
16
11
40
12
43
The main problem with interaction matrices is that the action/single-effect
format is unrealistic and leads to difficulties in identifying sequential impacts
and causes. Also, categories of actions or types of indicators are mutually
exclusive, whereas in reality they overlap considerably. The Leopold Matrix
tends to be subjective because each assessor develops his or her own
mental ranking on the 1-to-10 scale. The Matrix fails to identify uncertainty
(arising from insufficient information) and environmental variability, including
the possibility that extremes might present unacceptable hazards. Its ease of
use makes the interaction matrix a useful tool for initial stages of an
environmental impact assessment despite its numerous limitations. The prime
value of an interaction matrix is illustrative rather than analytical.
PREPARATION OF AN ENVIRONMENTAL STATEMENT
In order to assess the impacts of a scheme it is necessary to characterise the
existing conditions. This requires the collection and study of existing data and
the commissioning of 'baseline' surveys. Existing data can include aerial
photographs, OS maps, soil and geological surveys. This data is used to
identify gaps in the data sets and decide what sort of field surveys are
required. These need to be carried out following a systematic, replicable
methodology so that differences in later surveys can be attributed to the
development (or other factors) not methodological errors. Around 300
environmental statements (ESs) are produced annually and their quality, and
that of the EAs of which they are part, varies from the exemplary to the poor.
Consultation is a legal requirement to ensure the public are fully informed of
the effects of a development and have an opportunity to discuss the scheme,
its impacts and mitigation before a planning decision is made. Consultees
should be approached as early as possible so that objections are identified at
an early stage when modifications can be more easily incorporated in to a
project. Reference should be made to statutory and non-statutory bodies
consultees:
The next stage is the identification of the possible impacts, evaluation of their
effects and possible mitigation measures. Typically an ES would have
several sections, i.e.:
 Planning framework
 Development proposal
 Archaeology
 Ecology
 Landscape
 Water quality
 Air quality
 Waste
 Traffic
 Social effects
 Non-technical summary
These elements are considered in terms of:
 Baseline conditions
 Development features
 Anticipated effects
 Mitigation
 Residual impact
The potential environmental impacts of a project can be predicted and
evaluated by a variety of techniques depending on the type of impact and
project. Methods include:
 subjective assessment/experience
 baseline assessment/site monitoring
 physical modelling
 mathematical modelling
 behavioural studies
 risk assessment
The use of computers for mathematical modelling has expanded greatly in
recent years with the availability of powerful PCs and specific software for
environmental evaluation.
The environmental impacts can then be assessed in terms of significance and
compliance with appropriate environmental standards and/or community
expectations. Once the main impacts have been identified mitigation
measures can be examined.
These may be just ensuring effective
management or control of a site or may involve measures which form a
permanent and integral element of the development and its operation. This
will also involve measures to monitor the effectiveness of mitigation
measures. Mitigation measures can include:
 select alternative location
 modify site layout
 modifying working practices during construction
 control impacts arising from development (pollution control)
 landscaping and screening structures
 traffic management/road improvements
 financial compensation
 off site tree planting (recreation, wind shelter, CO2 mitigation)
As well as mitigation measures there could be possible measures to enhance
aspects of the project to provide habitats etc. These should also be
considered.
The results of these studies are incorporated in to an environmental
statement, which should communicate the findings in a clear and logical
manner.
REVIEW OF ES
The review stage is carried out by the statutory body responsible for the EA,
where it is ensured that the EA has been adequately completed within the
terms of reference. The decision on planning permission is then made.
This is often not the end of the EA process as many projects may end up at a
public enquiry or in parliament discussions, where the ES will be under great
scrutiny. It is therefore important that is written and technically prepared to a
high standard so that its integrity is not questioned. Even if planning
permission is granted, the EA continues via monitoring of the actual impacts
of the development and monitoring of the accuracy of predictions made in the
ES over the lifetime of the project.
EXAMPLE OF EA FOR WASTEWATER TREATMENT PROJECTS
Projects for wastewater treatment fall under annex II, i.e.
 wastewater treatment
 sludge disposal
in the UK it is up to the local planning authority to decide if an EA is required
for such a project (an appeal is allowed to the Secretary of State for the
Environment against a decision to undertake an EA). The ES is submitted
with the planning application to the local planning authority, copies are sent to
the consultees and also made available for public comment.
Statutory consultees for such a project would likely include:
EA
local and county authorities
Countryside Commission
English Nature
HMIP
MAFF
Non-statutory consultees could include:
riparian owners
local anglers
RSPB
British Waterways
parish council
tourist boards
etc.
The positive impacts of wastewater treatment need to balanced against the
potentially negative factors such as health hazards, visual and landscape
impacts and nuisance due to vermin, odour or traffic. There are a great many
legal acts to be observed and ideally the proposal should adopt BATNEEC
and BPEO.
The scoping exercise requires a multi-disciplinary team to consider the range
of engineering, environmental, economic, social and other affects a new
sewage works is likely to have.
The main environmental impacts are those associated with the processes
involved in treatment and disposal of effluents and sludge.
There are also more general considerations associated with built
development projects during the construction of the plant and its subsequent
visual impact
The table on the next two pages considers the major issues likely to arise
from the development of a sewage works; the causes and effects of the
impacts; it also identifies the relevant prediction tools and standards and
finally summarises possible mitigation measures.
EXAMPLES OF THE IMPACT OF WASTEWATER TREATMENT PROJECTS
ISSUE
Air Pollution
Odour
Stack emissions
Water Quality
Pollution from effluent
discharge
Sludge disposal
Land
Soil contamination
Physical Processes
Scour around outfall
Natural Habitats
Changes in aquatic
ecology around outfall
(cont.)
POSSIBLE CAUSE
TYPICAL EFFECTS
PREDICTIVE
TECHNIQUES
APPROPRIATE
STANDARDS
MITIGATION
Process and operation
of the works
Public nuisance
Examine histories
of complaints
Emissions from sludge
incinerators and dryers
Reduce air quality; public
health
Plume dispersion
models
Directives on
incineration and air
quality
Unauthorised
trade
pollutants; insufficient
treatment;
sensitive
waters
Poison and kill wildlife;
degradation
of
aquatic
ecosystem; health risk to
bathers.
Hydrodynamic and
water
quality
modelling
Runoff
from
agricultural land; landfill
leachate
Lower water quality; affect
ecology
Model runoff and
leachate
generation
EA
discharge
consents;
various
directives
(i.e.
UWWD and Bathing
Waters)
Directives on sludge
disposal
to
agricultural land and
landfill ???
Level of
treatment
appropriate
for
receiving waters; strict
supervision
of
discharge consent.
Use appropriate waste
management
procedures
Application of sludges
Build up of heavy metals;
pathogens affecting cattle
Study
soil
chemistry
and
application rates
Directive; UK
regulations (1989)
Follow practices set out
in legislation; control
composition of sludge.
Erosion of banks or
rock armour
Bank instability
Model scour
Settlement of solids;
oxygen
sag;
eutrophication
Lower variety of species;
increase in pollution tolerant
organisms
Case
histories,
water
quality
modelling.
Design works to avoid
odours (i.e. covers and
odour control units)
Control composition of
sludge; pollution
control technology
Locate
outfall
to
minimise scour; protect
banks
Design standards for
outfalls;
discharge
consents; directives
Upgrade
treatment;
accept
limited
degradation
EXAMPLES OF THE IMPACT OF WASTEWATER TREATMENT PROJECTS (cont.)
Health and Safety
Health Hazards to
humans and animals
Pathogens in sludge,
effluent and aerosols
Endanger health of grazing
animals; Risks to humans
consuming
shell
fish,
bathers, workers and local
residents
Socio-economic
Land Values
Siting of new works
Land and house prices fall
Good site selection and
screening
Polluted
beach;
odours; health risks;
loss
of
nature
conservation sites.
Pumping
Decline in local economy;
reduced number of visitors
Site works away from
amenity
areas;
landscaping, Improve
treatment
Soundproofing;
use
less noisy equipment
Construction
buildings;
stacks.
Damage
construction
Visual
intrusion
obstruction
Leisure and Amenity
Reduced
amenity
value
Noise
Cultural Heritage
Visual intrusion
Loss of heritage sites
site;
chimney
during
Case
studies,
water
quality
modelling;
air
dispersion
of
pollutant modelling
Shell fish; Bathing
water;
Sludge
application,
air
quality
directives
Directives
Reduced number of visitors
and
Loss of site of cultural or
conservation significance
Landscape
assessment
Local
authority
planning
Examine maps of
heritage
or
conservation sites
before construction
Countryside
Commission;
English Heritage
Improve
treatment;
follow H&S procedures
Screen or reinstate
site;
design
of
structures
Surveys to avoid sites;
relocation;
habitat
creation
EXAMPLE: PORTSMOUTH AND HAVANT WASTEWATER TREATMENT
PROJECT
The supplementary handout contains the non-technical summary of the
Environmental Statement relating to the proposal to treat the sewage from
Portsmouth at Budds Farm STW and discharge the effluent from the existing
long sea outfall at Eastney.
The UWWD secondary treatment of urban wastewater' and fixed effluent
standards are set for populations in excess of 10,000. Portsmouth currently
discharges screened sewage through a 5.7km long sea outfall. This will
sewage will now require secondary treatment. Various options in Portsmouth
were discounted and the plan is to pump the sewage to Budds Farm Nr
Havant for treatment and return the mixed Portsmouth and existing Budds
Farm effluent for discharge from the Eastney outfall.
Although wastewater treatment works fall under Annex II this project requires
an EA because:
 Langstone Harbour is a SSSI and a RAMSAR conservation area
 the pollutant discharges are of public interest, i.e. ERASE
 the scale of the project has implications on more than a local level
Nearly 60 main impacts of the project have been identified and these have
been classified for the nature, duration, significance and geographical level of
importance after mitigation measure have been implemented
Scoping was carried out in consultation with:
Portsmouth City Council, Hampshire County Council, Havant Borough
Council, EA, Langstone Harbour Board, English Nature, English Heritage,
MAFF, RSPB, Hampshire Wildlife Trust
Several predictive techniques were used to arrive at the impacts on:
Water Quality
Mathematical modelling of tidal movements incorporating the dispersion and
residence time of pollutants and bacteria
Odour
Baseline monitoring and use of the All Terrain Dispersal Model computer
software used commonly in air pollution studies.
Landscape
Subjective assessment and flying of balloons
Historic Buildings
Subjective assessment based on discussions with English Heritage and
Portsmouth City Council
Traffic and Highways
Subjective assessment and predictive calculations based on construction and
operational plans.
Ecology
Field surveys and desk top studies and consultation with RSPB, English
Nature and Hampshire Wildlife Trust
Noise
Comparison of predicted levels associated with construction and operating
practices with baseline conditions.
Land Contamination
Desktop studies and surveys
Sludge Recycling
Subjective assessment/experience
Baseline assessment/site monitoring
Others
Subjective assessment/experience
Baseline assessment/site monitoring
The main findings of these studies are summarised in the Non-Technical
summary Handout.