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Contaminated land

Last Modified May 14, 2019

There are rules and regulations that deal with contaminated land.

Land may have been contaminated by industries such as chemical works, gasworks, landfills and tanneries. These are often called brownfield sites and can be a problem because:

  • there may be harmful substances in, on or under the land
  • water pollution might be caused by substances at the site.

Land is only declared contaminated if:

  • it contains a source of pollution (known as the source)
  • someone (or something) could be affected by the pollutant (known as the receptor)
  • the pollution can get to the 'receptor' (known as the pathway)

These three elements together are known as the pollutant linkage.

Can I build / re-use contaminated brownfield sites?

Any development is likely to need planning permission The approval of an application for redevelopment will only be granted on condition that the contamination is cleaned up to a standard that makes it suitable for the new use of the land.

Can I buy or sell contaminated land?

You will need specialist advice from an environmental consultant or a specialist lawyer before you buy or sell contaminated land.

How do I know if a piece of land is contaminated?

We can tell you if a site in Hertsmere has been declared contaminated land.

We also keep a public register of contaminated land sites which documents enforcement action taken by us in relation to the clean-up of contaminated land. There are currently no entries on our contaminated land register.

I own some contaminated land. What should I do?

If you own or occupy contaminated land now, or you did in the past, you may be responsible for cleaning up the pollution. You may still be responsible for cleaning up the pollution after you have sold the land.

Some contamination can be a hazard to current occupants or neighbours and the law says the problem must be put right immediately.

Will it cost me?

The law states that the person or organisation that caused, or permitted, the contamination must pay to put it right. If that person or organisation is not known, then the current owner of the land may become responsible.

Owners and occupiers of domestic properties are not usually liable for these costs.

What do we do about contaminated land?

We have a Contaminated Land Strategy  which says how we will find contaminated sites in our area.

We will then:

  • carry out inspections of land that may be contaminated
  • find out who is responsible for putting right the contamination and discuss the problem with them
  • formally declare land as being contaminated
  • agree the necessary action and make sure it is done
  • keep a public register of contaminated land sites, the action that was required to put the problem right and any legal action that has been taken.


In some cases the Environment Agency may take over the regulation of a site from us once it has been declared as contaminated land.

Environmental information


We can provide environmental information on sites within Hertsmere, including details of site investigations and remedial works, location of former landfill sites, details of authorised industrial processes, pollution incident records and details of other information held on public registers.

We charge £95 to provide written responses to environmental information requests. You will need to submit an environmental information request if you want this information.

Please note that requests for environmental information can take up to 10 working days to complete.

Developing a piece of contaminated land

If a piece of land is to be re-developed or have its use changed, and the land could potentially be contaminated, then this is usually dealt with under the Town and Country Planning Act.

It is the responsibility of the owners and/or developers of the site to establish the extent and nature of any potentially harmful materials on the site. This should normally be done before the formal planning permission is granted for the development. However, if this is not possible, permission can be granted, but certain conditions regarding land contamination will be attached to the permission, which must be met.

If potential risks are identified, the land will need to be dealt with before development begins, to minimise all risks posed. This process is known as remediation.

Herts_and_beds_guidance_revision_2018 (591kb) Guidance Revision 2018 PDF(591Kb) helps applicants, developers, land owners and consultants meet the planning requirements for a potentially contaminated site.

The Council is mindful of the potential cost implications of a formal land contamination assessment and investigation.  Therefore, the Council has prepared a questionnaire to be completed by planning applicants for small (1 or 2 house) housing developments on existing residential or green-field sites.  The information contained in completed questionnaires is then used to determine whether a more formal assessment of land contamination is necessary.

Land contamination self assessment for small development sites with proposed sensitive end uses.

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