Site contamination can occur as a result of the introduction of chemical substances that are above background concentrations to a site. If site contamination exists then it must be determined who is the appropriate person. The appropriate person has responsibility for implementing and funding the assessment and remediation of site contamination and, if necessary, independent auditing by a site contamination auditor. In certain circumstances the site owner rather than the actual person who caused the site contamination may be deemed to be the appropriate person.

Holders of EPA licences can transfer liability for site contamination if they are transferring their licence to another person.

A person selling their property has an obligation to inform prospective purchasers of any knowledge of site contamination and activities that may cause site contamination.