National Priorities List (NPL) Law and Legal Definition

National Priorities List (NPL) is a list that contains the most serious uncontrolled or abandoned hazardous waste sites identified for possible long term remedial action under Superfund. The list is based primarily on the score a site receives from the Hazard Ranking System. The Environmental Protection Agency (EPA) is required to update the NPL once a year. In order to receive money from the Trust Fund for remedial action, a site must be on the NPL.