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Impact assessment

The general framework of the impact assessment is provided by article R512-6 of the environmental code.
The content of the impact assessment must be proportional to the importance of the prescribed installation and its anticipated environmental impact with regard to the interests targeted in articles L511-1 and L211-1 of the Environmental code.

The impact assessment should successively present:

  • an analysis of the initial condition of the site and its environment, notably with regard to natural resources and agricultural, forest, maritime or recreational natural areas, as well as the material assets and cultural heritage likely to be affected by the project;
  • an analysis of the direct and indirect, temporary and permanent effects of the installation on health and the environment, in particular on sites and landscapes, fauna and flora, natural habitats and biological balance, on the well-being of local residents (noise, vibrations, odours, light emissions) or on agriculture, hygiene, health or public safety, on the protection of material assets and cultural heritage;
  • an analysis of the origin, nature and seriousness of the nuisances likely to result from the operation of the installation considered. To this end, it will specify in particular, as and when required, the nature and seriousness of waste, the noise level of the equipment to be used and the vibrations caused by this equipment, the methods and conditions of water supply and its usage;
  • the reasons why the project presented was selected from the solutions envisaged, notably in terms of environmental concerns;
  • the measures envisaged by the applicant to eliminate, limit and if possible compensate for the nuisances of the installation as well as an estimate of associated expenses. These measures should be described, specifying the projected layout and operating requirements, detailed characteristics as well as anticipated performance, notably in terms of underground water protection, treatment and disposal of wastewater and gas emissions, disposal of operating waste and residue, the conditions in which materials are brought to the installation to be treated, transport of manufactured products and the rational use of energy;
  • site rehabilitation conditions with the owner’s agreement;
  • for the installations belonging to the categories outlined by decree, an analysis of the methods used to evaluate the effects of the installation on the environment, mentioning the possible technical or scientific difficulties encountered when establishing this evaluation. The impact assessment must therefore tackle these chapters in order.

More concretely, the impact assessment should make it possible, for each major type of nuisances (water pollution, air pollution, noise, waste etc.), to establish the existing situation before starting up the installation, its characteristics and raw effects on the environment for each of these nuisances, the measures taken to reduce these effects and the expected situation after start-up. It should also provide information on the methods used to supply the installation and dispose of its products and by-products, as well as on its integration into the landscape.
If certain points do not seem to relate to the installation in question, it is necessary to succinctly explain why.
Among the measures taken, remediation measures “at source” should also be indicated, such as recycling, the choice of a non-polluting process etc.

Note: The list of points to be examined for each paragraph is not exhaustive. Furthermore, certain problems can be particularly relevant depending on the local context. In this case, more in-depth investigations will be necessary, possibly involving specialised consultancy firms (example: hydrogeological survey for quarries in relation to the groundwater table).

3Analysis of the initial condition of the site and its environment3

Different themes:

  • Environment
  • Water pollution
  • Air pollution
  • Soil pollution
  • Noise Vibrations
  • Waste
  • Transport Supply
  • Risks
  • Subsoil

N.B.: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive


  • General description of the environment of the installation: occupation of the area – initial condition
  • Natural resources - agricultural, forest or recreational natural areas.
  • Material assets and cultural heritage likely to be affected by the project.
  • Presence of workshops or plants, heavy industries, housing, public facilities, busy traffic lanes.
  • Urban planning documents – listed sites – archaeology – public easements.

Water pollution

  • Nearby rivers and waterways. Objectives in terms of quality – minimum water level – flow rates.
  • State of current nuisances: plants or built-up areas with upstream discharge (for a discharge into a waterway).
  • Usage: drinking water supply – irrigation – hydroelectricity.
  • When relevant, quality of the receiving milieu with regard to the pollutant(s) discharged by the installation.
  • Aquatic environment – fauna – flora.

Air pollution

  • Existence of current nuisances (built-up areas, plants, workshops etc.) including odour problems.
  • Urbanization: high, moderate, low.
  • Direction of prevailing winds. Compass rose.
  • Existence of adverse conditions (area prone to fog etc.)
  • Nature, dimension and distance of obstacles likely to restrict the diffusion of flue gases (buildings, hills etc.).

Soil pollution

  • Existence of pre-existing pollution (what are the pollution sources, possible transfer channels and population and environment sections likely to be affected);
  • Compatibility of the state of the environment with existing or projected usage, whether on site or off site (in connection with the health section of the impact assessment).

Noise Vibrations

  • Existence of current nuisances (workshops, plants, roads, railway, planes etc.). When relevant, time when the nuisance occurs.
  • Urbanization: high, moderate, low.
  • Existence of a sensitive local context (hospitals, retirement homes, schools, offices, walkway etc.).
  • Nearby housing (distance) or other elements to be preserved.


  • Existing situation: nearest treatment and storage centre, disposal channels etc.

Transport Supply

  • Existence of nuisances associated with nearby traffic (example: heavy goods vehicles passing through residential areas).


  • Other nearby installations, potential risks generated
  • Isolation distances.
  • Urbanization: high, moderate, low.


  • Land: permeability, geology.
  • Groundwater table: underground water circulation.
  • Use of groundwater table.

3Analysis of the direct and indirect, temporary and permanent effects of the installation on health and the environment3

Note: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive

The environment

  • Integration into the landscape or site
  • Impact on fauna and flora
    • airborne
    • aquatic
    • subterranean
  • Impact on natural resources (air, water, soil and subsoil)
  • Impact on biological balance
  • Impacts on residents’ well-being
    • noise
    • vibrations
    • odours
    • light emissions
    • vehicle traffic
  • Impact on agriculture
  • Impact on public hygiene, health and safety
  • Impact on the protection of assets and cultural heritage
  • Impact associated with the works required to start up the installation


The impact assessment should examine the consequences of the project on the health of the population. The method for examining this impact is applicable to all categories of classified installations, from those with low potential impact on health to those manipulating very hazardous substances. For better document clarity, we recommend that this examination mention the parts of the impact assessment dealing with all or some of the questions below. It is proportional to the health risk caused by the installation.
The approach to public health risk assessment includes in particular:

  • an inventory of substances and nuisances, gas, dust, electromagnetic fields, radioactivity, various pollutants (light emissions, noise, vibrations, odours) implemented and generated by the installation
  • the determination of their intrinsic adverse effects and combined effects,
  • the determination of the means of exposure of the population and the environment as well as the identification of potentially affected populations,
  • the quantitative evaluation of populations’ exposure to the different substances and nuisances of the installation, under normal and critical operating conditions,
  • the characterisation of the health hazard caused by the installation. So-called “threshold” substances, for which a risk index between exposure level and probable toxic effect can be calculated, should be distinguished from “no-threshold” substances, such as carcinogenic substances, for which the risk level is expressed in terms of probability of a person developing a disease.
  • the risk for the population must be assessed in relation to pollution exposure scenarios.
  • Priority is given to current health standards and resorting to modelling should only be considered in the absence of regulatory standards. Even then, special attention should be paid to the validity of the models used and the default parameters used in these models.

3Analysis of the origin, nature and seriousness of the nuisances likely to result from the operation of the installation3

Note: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive

Water pollution

  • Water supply and usage conditions
  • Origin of the water used (groundwater, water system etc.), flow rate
  • Cooling water: flow rate, collection, discharge, recycling
  • Process water: source, flow rate, quality, concentration and pollutant streams, impact on the site, receiving milieu
  • Discontinuous water (washing, water removal, draining etc.); same information
  • Risk of accidental pollution (storage or use of poisonous substances, hydrocarbons, acids etc.)
  • Rainwater collection and discharge method – measures in case of storm

Air pollution

  • Boiler room: power, nature and sulphur content of the fuel used
  • Origin and nature of the products discharged into the atmosphere (flue gases, steam, dust, solvents, nitrogen oxide, sulphur dioxide etc.)
  • Hourly flow and pollutant concentration of this discharge
  • Possible pollutants discharged by the exhaust air of the workshops (nature and flow)
  • One-off discharge (draining, discontinuous processes, valves)
  • Existence of odorous products

Soil pollution

  • Installation, products, depots, piping systems likely to contaminate the soil
  • Existing environmental monitoring (existing wells or piezometers), possible outlets or transfers (via air, underground and surface water, soil irrigation)
  • Potentially exposed populations and sections of the environment

Noise - Vibrations

  • Number and characteristics of noisy equipment and machines used
  • Anticipated noise level of these machines
  • Usage frequency (continuous, 1hr/day etc.)
  • High-intensity one-off, accidental or intermittent noises (siren, valves, falling metal plates, hammering etc.)
  • Anticipated weighted particle velocity of the vibrations around nearby residential areas or areas to be protected


  • Waste production at each step of the manufacturing or maintenance process
  • For each type of waste:
    • name
    • code under the waste nomenclature
    • quantity
    • volume – polluting nature
    • disposal or recovery method, internal or external
    • packaging method
    • composition and main characteristics with regard to the disposal process currently in place
    • quality and quantity variations

Transport – Supply

  • Volume of traffic generated by the facility (arrival-departure)
  • Conditions in which materials are brought to the installation to be treated and transport of manufactured products
  • Profile of the raw materials, intermediate products or finished products: nature, physical, chemical or toxicological characteristics
  • Schedule of arrivals
  • Villages or built-up areas necessarily affected by the new traffic

3Reasons for the choice3

Note: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive

Objective criteria (choices should be justified):

  • technical
  • economical
  • environmental
  • other alternative solutions

For large quarry sites, the possibility of evacuating materials by means other than road, such as railway, should be envisaged.

3Measures envisaged to eliminate, limit and, if possible, compensate for the nuisances of the installation3

Note: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive


  • Location of the installation in relation to the site or landscape

Water pollution.

  • Manufacturing process limiting water consumption or pollution
  • Cooling process eliminating or limiting water consumption
  • Water separation (rainwater, process water, domestic water etc.)
  • Specific operating procedures
  • Nature of wastewater treatment: performance, efficiency
  • Hourly flow and pollutant concentration after treatment
  • If discharge into the sewer system:
    • existence of a wastewater treatment plant at the other end
    • agreement with the operator of the system and plant to treat this discharge
  • Discharge monitoring process
  • Environmental monitoring (general biotic index etc.)
  • Cost of associated expenses

Air pollution – Rational use of energy

  • Fuels or processes limiting pollutant emissions and energy consumption
  • Possible gas recycling
  • Characteristics of the systems implemented to ensure the proper diffusion of effluents (smokestack height and diameter, evacuation velocity etc.).
  • Calculation of smokestack height in accordance with statutory texts
  • Nature of intended dust removal processes and treatment facilities. Expected performance
  • Characteristics of gas emissions after treatment (hourly flow, monitoring system, pollutant concentration). Odour treatment.
  • Discharge monitoring system
  • Cost of associated expenses

Soil pollution

  • Characteristics of discharge after treatment (hourly flow, monitoring system, pollutant concentration).
  • Discharge monitoring system
  • Measures intended to prevent accidental soil pollution or limit its impact.
  • Remediation techniques implemented if the initial condition of the environment is not compatible with the intended usage.
  • Cost of associated expenses

Noise Vibrations

  • Noise prevention at source (choice of machines etc.)
  • Sound proofing systems used (enclosure, anti-vibration base, noise screens, walls etc.)
  • Prepared operating procedures
  • Hours of operation
  • Expected noise level at property boundaries
  • Cost of associated expenses
  • Resources implemented to limit vibrations (blasting patterns in the case of quarries etc.)


  • Description of recycling and recovery operations
    • specific studies and nuisances highlighted
    • if relevant, former study with negative results (summary, date, type of waste concerned, technique envisaged, reasons why it was not implemented)
  • Description of treatment or pre-treatment processes. For each treatment or pre-treatment installation, summary of the types of waste treated, indicating incoming conditions and whether waste is mixed
  • External treatment and pre-treatment methods: Name and address of the treatment or pre-treatment centres outside the site
  • Internal treatment and pre-treatment methods: Thorough description and impact
  • Description of landfilling treatment processes: Same information as for abovementioned processes and mixed waste
  • External disposal methods: Name and address of the regrouping or disposal centres outside the site
  • Internal disposal methods
    • description
    • if internal landfill: geological and hydrological situation, land and groundwater table characteristics
    • former internal landfill
  • Intermediate storage: Type of waste concerned, technical conditions, average storage duration, quantity variations in time, subsoil protection
  • Technical-economic study of alternative waste management solutions
  • Presentation and technical-economic justification of waste management options selected
    • reasons for the choice of treatment process for each type of waste
    • waste management evolution

Transport - Supply

  • Resources implemented to prevent nuisances associated with new traffic (route, schedule etc.)
  • Transport of internal and external waste
  • Procedures provided to this end.


3Site rehabilitation conditions3

Note: the following are examples of elements which can be included in each theme but should under no circumstances be considered as exhaustive

Since 23 March 2000, the description of rehabilitation conditions after operation has been extended to all classified installations. This section should be adapted according to the type of installation (quarry, waste storage or other installation).

Operating method

  • excavation, stripping, extraction, operation phasing (with plan), storage (soil, materials)


  • Principle: use or destruction of the buildings and infrastructures, backfilling (method, origin of the backfill, monitoring etc.), evening out of the land, frontage or embankments (slopes, condition, site safety etc.)
  • restoration: agricultural, plantations, grass planting, cleaning and maintenance

Final condition

  • description, plans, cross-sections, visual perception graphics from significant points, rehabilitation cost