Contaminated land

This guidance is primarily for property owners and developers who want to know what information they should submit to the Planning Department when they apply to redevelop, or significantly change the use of land or buildings, which could potentially be contaminated.

Contamination, in most cases, is likely to arise from a previous use of the site, or an adjacent site, that had an industrial or waste disposal activity on it at one time or another.

The presence of contamination does not necessarily present an unacceptable risk. However, risk arises when a pathway is created between a contaminant and a vulnerable receptor. The contaminant may be chemical, biological, radioactive or physical. Development can create risk by introducing new pathways and also by introducing new receptors – for example where houses are built near the site of a former landfill site producing methane.

Where development introduces a particularly sensitive use, such as houses with gardens, schools, or allotments, the possibility of land contamination should always be considered. For land to be contaminated there needs to be a pollutant linkage as shown below.

Sources      >      Pathway       >        Receptor

Planning applications

The presence, or the potential presence, of contamination is a material consideration when the council considers planning applications. The council wishes to ensure that development will not create or allow the continuation of unacceptable risk. The standard of remediation to be achieved is the removal of unacceptable risk, making the site suitable for its new use and ensuring that it does not cause pollution of the wider environment.

An assessment of risk should always be carried out by the developer before the planning application is submitted.

Below are the stages for assessing risk, proposing a remediation strategy and producing evidence that the work has been carried out satisfactorily.

Where land is known to be affected by contamination, or where this is likely due to past uses, developers should submit with the planning application a Stage 1a Study, which is the minimum requirement. This will include desk-based research, site reconnaissance and hazard identification.

It is advisable for the developer to liaise with the council before submitting a planning application in order to discuss specific site details. Where significant contamination is known or suspected, additional research and risk assessment may be needed before an application can be determined. If applications cannot be approved due to lack of information, and if circumstances indicate possible unacceptable risk, then planning permission may be refused. All aspects of investigations into possible land contamination should follow the guidelines within CLR11 Model Procedures for the Management of Land Contamination.

Examples of potentially contaminating uses:

• metal processing and finishing;
• gasworks;
• oil and petroleum storage;
• manufacture of chemicals including paints, fertilisers;
• timber treatment;
• landfill sites;
• scrap yards;
• abattoirs;
• railway or road haulage depots;
• military land.
  

Use of planning conditions

There will be circumstances in which the past use of the land or buildings suggests the possibility of contamination. Examples might include buildings previously used for light industrial purposes or for agricultural use. In such cases the council may impose a condition on any grant of planning permission. Such a condition would ensure that the site is investigated and any necessary remediation is carried out before development takes place.

Conditions may also be used where the council is satisfied that the risks are understood and that there is a remediation option, but where not all the details have been resolved.

Other legislation

The standards for cleaning up land under the planning process are to achieve a minimum standard so that the property cannot be registered under Part IIA of the Environment Protection  Act 1990 (www.opsi.gov.uk/acts/acts1990/Ukpga_19900043_en_1.htm). This guidance does not apply to the cleaning up of land under Part IIA of the Environment Protection Act, although the information that we would request is very similar. For details on Part IIA, please contact the Environmental Protection Team.

Building regulations approval may also be required and the applicant must ensure that the Building Control Department are aware of contamination issues and that the appropriate requirements are met.

Further information

Planning Policy Statement 23: Planning and Pollution Control Annex 2: Development on Land Affected by Contamination (www.communities.gov.uk/publications/planningandbuilding/pps23annex2), published by the Department of Communities and Local Government.

Stages in a contaminated land assessment

Stage 1 – Planning and desk study

All aspects of investigations should follow the guidelines within CLR11 Model Procedures of the management of Land Contamination.

Phase 1a – Desk based research, site reconnaissance, hazard identification

• Research site history to establish if previous uses could have led to contamination.
• Obtain as much information of the previous uses and potential contaminants as possible so as to highlight which areas of the site could be affected (including adjoining land where such risks exists). Ask the Environmental Protection Team for directions to any further land contamination guidance that the council may have.
• Identify who and what is a risk (e.g. future occupants, buildings and environment) and the potential pathways for those risks – known as the Conceptual Site Model.
• Submit a report of the hazard identification to the Planning Authority when submitting the application. If required, discuss findings with relevant authorities, i.e. Borough Council and Environment Agency.
• The Planning Authority will then decide if the submitted report is to be accepted and whether there is a need to proceed to the next stage.

Phase 1b – Further desk based research, exploratory site investigation, hazard assessment

• Using the information above, the applicant will need to undertake an initial intrusive investigation. Please note that monitoring for substances such as ground gas can take several months.
• Review Conceptual Site Model.
• Decide which risk assessment modes are appropriate or need to be developed. Discuss and agree with the Planning Authority. Submit a report of the hazard assessment to Planning Services. If required, discuss findings with Medway Council and Environment Agency.
• The Planning Authority will decide if the submitted report is to be approved and if there is a need to proceed to next stage.

Stage 2 – Risk estimation and assessment

Phase 2a – Intrusive investigations

• The applicant will now need to determine what detailed intrusive work is required and what monitoring/sampling techniques need to be used.
• Identify how many samples will be needed for confidence and take guidance from a laboratory providing appropriate United Kingdom Accreditation Service accredited analysis. Produce a methodology and timetable for carrying out the work. Carry out intrusive investigations.
• Use the estimation to inform a risk assessment and if required, discuss findings with Medway Council and Environment Agency.

Phase 2b – Risk assessment

• Assess the risks by applying appropriate human health (following the CLEA methodology) and non-human health assessment criteria, as agreed during Phase 1b. Refer to CLR Report 11: Model Procedures for the Management of Land Contamination.
• Identify remediation options and develop a Remediation Strategy including a timetable.
• Submit a report of the risk estimation and assessment to Planning Authority. Agree the Remediation Strategy and inform all relevant interested parties (Planning, Environmental Health, Environment Agency, Building Control/NHBC) and identify a single point of contact at Medway Council for follow up issues.
• The Planning Authority will decide if the submitted report is to be approved.
• After approval, proceed to next stage if necessary.

Stage 3 – Remedial action

• Implement Remediation Strategy with regular updates to single point of contact including unforeseen work.
• Where appropriate, seek site visits from Medway Council staff.

Stage 4 – Closure report

• Upon completion produce a concise documented evidence report of investigations, remedial action and validation undertaken to enable the Planning Authority to discharge any planning conditions.

Notes:

• Compliance with the Building Regulations is a separate issue and there should be close discussion in appropriate cases with Medway Council’s Building Control Service or with the National House Building Council. at www.nhbc.co.uk/

• Medway Council staff will use the documented evidence referred to in Stage 4 to reply to all enquiries on a Land Charge Search.

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