PRPs: What Are They?

After a contamination, EPA begins a cleanup and enforcement process. The process is lengthy and complex. A first step involves identifying Potentially Responsible Parties (PRPs). These PRPs include the people and/or entities potentially responsible for the contamination.

PRPs: Evaluation

Evaluation of a responsible party is a detailed process. Because of this, EPA scrutinizes all potentially responsible parties carefully. EPA uses various means for evaluating liability, including:

1. site investigation and sampling;
2. interviews with witnesses;
3. document review;
4. title searches; and
5. other investigative research conducted online and in libraries.
EPA seeks to match waste found contamination sites with potentially responsible parties.


Once locating PRPs, EPA examines a party’s involvement at the contamination site. Involvement at a contamination site means many different things. It might mean ownership of the site. It also might mean ownership of a business operating on or near the site. In some cases, involvement can even mean rental or sublet of the site. The involvement in some cases might occur years before the contamination occurred or was discovered. even years before the contamination occurred or was discovered.
EPA considers the amount of waste each party may have contributed, as well as a party’s ability to pay for, or pay partially for, a site’s cleanup. EPA evaluates a party’s likely defenses, and any applicable exemptions or exclusions.


In situations where PRPs are identified, EPA seeks to enforce responsibility. EPA ensures public health by asking PRPs to conduct their own investigations and begin site cleanups before the deployment of any public resources. However, some public resources do exist for cleaning up mass scale contaminations.


EPA’s mechanism for responding to mass scale contamination is informally called the Superfund Program. The Superfund is a part of the Comprehensive Environmental Response, Compensation, and Liability Act (“CERCLA”). CERCLA passed in 1980 in response to hazardous waste practices in the 1970s. Superfund/CERCLA addresses thousands of contaminations nationwide.

Superfund is a great way to take care of contaminations caused by oil spills and natural disasters. However, EPA reserves the Superfund for significant contaminations where PRPs are absent, or not able to pay for cleanup. Finding PRPs and making sure they contribute maximizes the good the Superfund can do with limited resources.