Legal Definitions - NPL

NPL stands for the National Priorities List.

The National Priorities List (NPL) is a public list maintained by the U.S. Environmental Protection Agency (EPA) that identifies the most serious hazardous waste sites in the United States. These sites are considered eligible for long-term federal cleanup actions and funding under the Superfund program. Inclusion on the NPL signifies that a site poses a significant risk to human health and the environment, requiring comprehensive investigation and remediation efforts.

• Example 1: Contaminated Industrial Zone

  Imagine an old industrial area where several factories operated for decades, improperly disposing of chemicals into the soil and groundwater. Over time, residents in a nearby community start reporting unusual health issues, and tests reveal widespread contamination of their drinking water wells. After an initial investigation, the EPA determines that the level of pollution poses a severe threat to public health and the environment. This site would likely be added to the National Priorities List, making it eligible for federal Superfund resources to conduct a thorough cleanup, remove hazardous waste, and restore the affected areas.

  How it illustrates the term: This scenario demonstrates how a site with significant, widespread hazardous contamination, posing a direct threat to a community, qualifies for inclusion on the NPL to receive the highest level of federal attention and resources for remediation.

• Example 2: Abandoned Mining Operation

  Consider a historical mining district where operations ceased many years ago, leaving behind large piles of mine tailings (waste rock) and open pits. Rainwater and snowmelt flow through these tailings, picking up heavy metals and other toxic substances, which then drain into nearby rivers and streams. This acid mine drainage pollutes the waterways, harming aquatic life and potentially affecting agricultural land downstream. If the EPA assesses this site and finds that the ongoing pollution constitutes a major environmental hazard that cannot be addressed by state or local governments alone, it could be placed on the National Priorities List. This designation would allow the EPA to fund and manage a long-term project to stabilize the tailings, treat the contaminated water, and restore the ecosystem.

  How it illustrates the term: This example shows how historical industrial activities, even if long abandoned, can create persistent environmental hazards that, if severe enough, warrant listing on the NPL for federal intervention and cleanup.

• Example 3: Leaking Municipal Landfill

  Picture an old municipal landfill that was not constructed with modern lining systems. Over many years, hazardous substances from household and industrial waste began to leak from the landfill, forming a plume of contaminated groundwater that slowly migrated towards a nearby residential subdivision. Residents notice strange odors and taste in their well water, and subsequent testing reveals dangerous levels of chemicals. The EPA investigates and concludes that the landfill is a significant source of pollution threatening the community's health. The site would then be added to the National Priorities List, enabling the EPA to oversee and fund the design and implementation of a comprehensive cleanup plan, which might include containing the landfill, treating the groundwater, and ensuring safe drinking water for the affected residents.

  How it illustrates the term: This situation highlights how a public facility, if it poses a severe and widespread threat due to hazardous leakage, can be designated an NPL site to ensure federal resources are directed towards protecting public health and the environment.