In 1989, Brookhaven National Laboratory was placed on the U.S. Environmental Protection Agency's "National Priorities List" for cleanup of hazardous waste and groundwater contamination. The Laboratory was added because of the environmental effects of some past practices that impacted the aquifer.

Since that time, many actions have been taken to reduce or eliminate risk to human health and the environment. One of the first was to remove any remaining sources of groundwater contamination. Next, the Lab installed several treatment systems to help prevent on-site groundwater that was already contaminated from moving off site.

Throughout the 1990s, thousands of on- and off-site groundwater samples were taken to characterize the makeup and movement of the contaminant plumes. To protect the public’s health and the environment, in 1996 the U.S. Department of Energy, BNL’s landlord, provided free public water hookups to more than 1,500 homes and businesses in areas south and southeast of the laboratory that previously used private well water.

In addition to the six groundwater cleanup systems already operating on and off the Lab site, six additional off-site systems are planned for construction over the next several years.