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Dealing with Land Contamination Through the Planning Regime

Brownfield sites are those which have been previously developed 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.

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 Natural Resources Wales on particular issues such as those sites that may impact controlled waters.

Conditioning of Planning Applications

The Contaminated Land Team consider potential land contamination issues for proposed developments when a planning application is received by the Council. Planning applications, particularly those with a potentially sensitive end use, are checked for potential land contamination issues on or within influencing distance of the proposed development site. Based on the information available, the Team will advise when a statutory planning condition is appropriate to ensure potential risks are assessed and mitigated to ensure that the land is suitable for the proposed new use in accordance with recognised standards. In some cases, the Team may advise planning permission is 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.

  1. It is strongly advised that any developer with a planning condition requiring a contamination assessment contacts the Contaminated Land Team to discuss the matter further.

  2. The minimum requirement for any contamination assessment is a Preliminary Risk Assessment (Desk Study). This should identify all of the potential ‘contaminant linkages’ and inform you as to whether an intrusive site investigation is required. It is recommended that this is submitted for comments prior to an intrusive investigation being undertaken. This allows for consultation with the Team on the scope of the next phase of works.

  3. Site Investigation/Quantitative Risk Assessment. This implements the scope of works as detailed in Item 2 (if needed). 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 for comments and written approval obtained on the sufficiency of the report prior to the development commencing or remedial works taking place on the site. It is possible that further intrusive works may be required to satisfy the Team that all contamination issues have been adequately addressed.

  4. If it is found that there are no contamination issues then the Contaminated Land Team will recommend that the condition is discharged. It may be appropriate to withhold discharge of the condition requiring verification of remediation works in case any unforeseen contamination issues arise during the works which need to be dealt with and documented for approval.

  5. 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 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.

  6. 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. On receipt of a satisfactory Validation Report, the Team will recommend 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 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 Team for further guidance.

Number of Sites Dealt with via the Planning Regime

Since 2002 statutory measures have been put in place to ensure that any land contamination issues are dealt with on many sites with planning permission in the Borough. The table below indicates the number of sites and area of land which has been dealt with through the planning regime at the time this webpage was updated. A significant number of other sites also have conditions and these will be assessed/remediated in due course when the development of the site is initiated – these sites are not reflected in the figures below.

Year* Number of Sites** where land contamination conditions have been completed and recommended for discharge Total Area of Land Assessed / Remediated ***
2002 26 146,789m2 (14.7 hectares)
2003 29 517,157m2 (51.7 hectares)
2004 34 470,851m2 (47.1 hectares)
2005 30 1,151,640m2 (115.2 hectares)
2006 13 77,588m2 (7.8 hectares)
2007 19 101,453m2 (10.1 hectares)
2008 13 184,095m2 (18.4 hectares)
2009 8 51,525m2 (5.2 hectares)
2010 13 121,553m2 (12.2 hectares)
2011 9 114,332m2 (11.4 hectares)
2012 12 213,191m2 (21.3hectares)
2013 11 123,996m2 (12.4 hectares)
2014 9 85,643m2 (8.6 hectares)
2015 10 317,590m2 (31.8 hectares)
2016 2 3362m2 (0.3 hectares)
Total 238 3,680,465m2 (368.1 hectares)


* whilst the works undertaken have been logged against a planning permission of a particular year, it may be the works were undertaken in a different year.

** these figures include land where potential contamination issues may be present due to a former use on the site itself or land that is within influencing distance of a former landfill and therefore needs risk assessment for gas migration risks.

***these figures are correct on the day of the webpage update, it should be noted that new work may commence on currently valid planning permissions (those less than 3/5 years old) which is not represented above therefore figures for the last 5 years may change (increase).

N.B. 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 (see downloads) summarises key actions and broadly advises how to undertake a contamination assessment, but the more detailed guidance should be referred to throughout the assessments/works undertaken. It should also be noted that new guidance is frequently being published and therefore may supersede or supplement guidance referred to here.

Below are examples of the type of guidance documents that should be consulted during a contamination assessment.

Any application should be made in accordance with guidance presented in Planning Policy Wales.

The Council has prepared a Local Planning Guidance Note ‘No 23 – Development of Sites with Land Contamination’ and has adopted the WLGA/EAW ‘Development of Land Affected by Contamination: A Guide for Developers’ and the WLGA ‘Requirements for the Chemical Testing of Imported Materials for Various End Uses and Validation of Cover Systems’.

National Quality Mark Scheme (NQMS) – Wrexham CBC’s Position Statement

Wrexham CBC welcome the introduction of a scheme which aims to improve the quality of contamination reports submitted to Councils under the Planning Regime. Endorsement of the NQMS by Welsh Government (and ideally NRW too) would be expected so as to enable the Council to recognise the scheme.

Notwithstanding this, on receipt of a report with the NQMS mark we would hope to find the review of the report to be straightforward and be able to determine it as acceptable ideally without any queries at all.

CLOs are required to advise on whether a report meets the requirements of the condition on specific planning permission and this will only be possible by reading and reviewing them. Furthermore Officers need to be aware of land contamination issues at sites and be aware what works have been undertaken in that regard, this will ensure all duties afforded to Councils are met (as primary regulators for land contamination/contaminated land). Therefore Wrexham will not take the view that this Scheme is a means to streamlining the satisfaction of conditions to the point at which a submitted report is accepted without consideration.

Further information on The Land Forum’s NQMS can be found here: www.claire.co.uk/projects-and-initiatives/nqms.