This concept is governed by a statutory framework, the most relevant being the introduction of new regulations into Part IIA of the Environmental Protection Act 1990 by the Environment Act 1995. These regulations impose a clean up liability where land is contaminated by substances that are causing, or likely to cause, significant harm or water pollution. The Local Authority is primarily responsible for taking regulatory action and identifying contaminated sites. In general terms the liability for clean up falls upon the persons who have caused or knowingly permitted the ‘pollution’.Prior to purchasing an interest in land, detailed investigations into contamination are usually carried out by an environmental consultant. Thereafter, a valuer will have to have regard to the contents of any environmental report in as much as it may affect the value of an interest in the subject property.A bank or mortgage company will often require that an environmental assessment takes place as a condition of the loan.