A-Z of Services

Dealing with Land Contamination Through the Planning Regime

Introduction

Land can be affected by contamination in the form of chemicals or gases in the soil and/or water, buildings, or other material on a site. Such sites are likely to be brownfield sites i.e. those which have been previously developed, often for commercial or industrial use, however sites where there has been historical mining may also have some contamination present.

As many developments are carried out on brownfield sites it is possible that some developments will take place on potentially contaminated sites. It is essential to ensure that potential contamination is adequately dealt with upon a change of land use, thereby ensuring the land is made suitable for its new use and presents no danger to the health and safety of people who come into contact with it. In some cases certain types of development (which are likely to be the most sensitive types e.g. housing) may not be suitable for sites with a certain type of contamination. In such cases the site may be better developed for another type of use, e.g. commercial or industrial.

For those developments in areas of historical metal mining there is the potential for contamination issues as a result of this historical land use. Historical metal mining can cause elevated heavy metals to be present within the soil and it is possible that such contamination may occur some distance from mining sites themselves. The Council takes a precautionary approach for developments in these types of areas.

Where developments are within 250m of a former landfill site they are considered to be within influencing distance of potential gas migration. Again, the Council takes a precautionary approach for developments in these types of areas and will condition applications accordingly.

The Council will consult with external stakeholders such as Environment Agency Wales on particular issues such as those sites that may impact controlled waters.

Conditioning of Planning Applications

The Development Control section within the Planning Department currently consults the Contaminated Land Team on potential land contamination issues of proposed developments when a planning application is received.

Planning applications, particularly those with a potentially sensitive end use, are checked with regards to the presence of potential land contamination on or within influencing distance of the proposed development site. For these proposed developments, where advised by the Contaminated Land Team (based on the limited information available to them), the Planning Department will require the Developers through the means of a Planning Condition on the Planning Permission to satisfy the Council that the presence of any contamination has been adequately assessed and subsequently ensure that the land is suitable (or made so) for the proposed new use in accordance with recognised standards. In extreme cases, planning permission may have to be refused or the application put on hold whilst further investigations take place.

How to Satisfy a Contamination Planning Condition

It is a statutory requirement to comply with a Planning Condition.

It is strongly advised that any developer with a planning condition requiring a contamination assessment contacts the Contaminated Land Team to find out why the condition has been imposed and discuss the matter further.
The minimum requirement for any contamination assessment is a Preliminary Risk Assessment (Desk Study). This should identify all of the potential pollutant linkages and inform you as to whether an intrusive site investigation is required. It is recommended that this is submitted to the Planning Department for comments prior to an intrusive investigation being undertaken. This allows for agreement with the Contaminated Land Team on the scope of the next phase of works.
Site Investigation/Quantitative Risk Assessment. This implements the scope of works as detailed in Item 2. On conclusion of these works the report is likely to demonstrate whether or not remedial works are required to ensure the development is suitable for use. It is essential that this is submitted to the Planning Department for comments and written approval obtained on the sufficiency of the report prior to any development works commencing or remedial works taking place on the site. It is possible that further intrusive works may be required to satisfy the Contaminated Land Team that all contamination issues have been adequately addressed.
If it is found that there are no contamination issues then the Contaminated Land Team will recommend to the Planning Department that the condition is discharged.
Should a site require remedial works, then a Remediation Strategy, Options Appraisal & Implementation Plan will be required. This details how the contamination will be mitigated to ensure the safe development of the site. It is essential that this is submitted to the Planning Department for comments and written approval obtained on the sufficiency of the remediation proposals prior to any development works commencing or remedial works taking place on the site.
During the remedial works and upon their completion, verification is required that the works have been undertaken in accordance with the remediation proposals agreed in Item 5. This should take the form a Validation Report which must be submitted for approval to the Planning Department. On receipt of a satisfactory Validation Report, the Contaminated Land Team will recommend to the Planning Department that the condition can be discharged. Please note that the development should not be occupied/used until the condition has been discharged.

Note To Applicants

Where, for example, a development is adjacent to a petrol filling station or is a barn conversion, the Contaminated Land Team will recommend to the Planning Department that an advisory note is placed on a planning permission. This Note is there to advise the developer that if they find any unexpected contamination to contact the Contaminated Land Team for further guidance.

Number of Sites Dealt with via the Planning Regime

Over a seven year period, statutory measures have been put in place which will ensure that any land contamination issues are dealt with on many sites within the County Borough. The table below details the number of conditions and note to applicants that have been recommended by the Contaminated Land Team to the Planning Department.

Year	Number of Applications Requiring Assessment by the Contaminated Land Team (% of total number applications received)	Total Number of Conditions Requested by Contaminated Land Team*	Total Number of Note to Applicants Requested by Contaminated Land Team	Total Number of No Comments
2002	289 (21%)	47	38	204
2003	282 (19%)	55	45	182
2004	427 (26%)	77	56	294
2005	523 (35%)	100	61	362
2006	596 (40%)	82	96	418
2007	434 (29%)	85	68	281
2008	328 (24%)	57	36	235
Total	2,879 (28%)	503	400	1,976

* conditions requested have not been counted twice where multiple applications have been submitted for the same site

Guidance to Help Satisfy a Contamination Planning Condition

There are many authoritative guidance documents available to aide Developers and their Environmental Consultants on how to carry out contamination assessments. The Developers Guide (available to download below) draws many of these documents together and advises how to undertake a contamination assessment through the planning regime. Please note that this document is now four years old and does not therefore take into consideration more recent guidance.

Please find below examples of the type of guidance documents that should be consulted during a contamination assessment.

BS10175 ‘Investigation of potentially contaminated sites – code of practice’
C665 ‘Assessing Risks posed by hazardous ground gases to buildings’
CLR11 ‘Model Procedures for the Management of Land Contamination’

This is NOT an exhaustive list, the Developers Guide has a list of further guidance available and new guidance is constantly being published.

At present there is no TAN (Welsh) equivalent to the planning guidance PPS23 (English), however the Contaminated Land Team considers PPS23 to be useful guidance that could be referred to.

The Council has prepared a Local Planning Guidance Note ‘No 23 – Development of Sites with Land Contamination’ and have adopted the ‘WLGA/WAG/EAW Land Contamination – A Guide for Developers’.

Land Contamination: A Guide for Developers