LANL Groundwater

Overview – Ground Water at LANL

The Pajarito Plateau, where Los Alamos National Laboratory (LANL) is located, was formed by volcanic activity in the Jemez Mountain Range. As a result, there are three zones of ground water below LANL – the alluvial, or shallow zone; the intermediate, or middle zone; and the regional aquifer (the sole drinking water source for Los Alamos County and LANL). Ground water can discharge at the springs along the Río Grande.Nuclear Facility LANL

Fast moving contaminants, such as chromium, perchlorate, and radioactive tritium, have been found in all three zones at levels exceeding standards. Los Alamos County shut down one of its drinking water wells because of concerns about perchlorate pollution. This fact sheet provides an overview of three discharge permits to be issued by the New Mexico Environment Department (NMED) that regulate discharges of treated industrial water to ground water at LANL.

Discharge Permit (DP) 1132 for the 52-year-old Radioactive Liquid Waste Treatment Facility (RLWTF), regulates radioactive liquid waste from the research, development and manufacturing of nuclear weapons at LANL. The NMED has never regulated the discharge. The permit, when issued, would regulate discharges of up to 40,000 gallons per day (gpd) to ground water from an outfall in Mortandad Canyon; a gas-generated Mechanical Evaporator System (MES); and two solar evaporator tanks (SET), each containing 380,000 gallons of treated liquids. 

Discharge Permit (DP) 1793 would allow for the land application of 350,000 gpd of treated (previously contaminated) groundwater from all on-site treatment and disposal facilities. It is an umbrella permit for individual work plans to treat chromium, high explosives (e.g., RDX) pump test waters, remediation production water, etc. The first work plan that LANL submitted to NMED for approval was rejected because LANL did not provide the information required in the permit.

Sole Source Aquifers in the Espanola basin Aquifer SystemCommunities for Clean Water (CCW) submitted detailed comments to the draft permit and requested a public hearing. In July, the NMED Secretary denied CCW’s request for a public hearing. With representation from the New Mexico Environmental Law Center, CCW is appealing the permit to the New Mexico Water Quality Control Commission.

Discharge Permit (DP) 1835 would allow the reinjection of 680,000 gpd of treated groundwater to the regional drinking water aquifer, which has special protections as the sole source of drinking water for over 50 percent of the people living in the area. A draft permit has not been released for public comment.

The three discharge permits would allow over 1.1 million gpd to be land applied or discharged across the LANL site in the arid southwest with no requirement for reuse.

If you would like to participate in these processes, please email Steve Huddleson at and ask to be placed on the LANL facility mailing list for DP-1132, DP-1793 and DP-1835.

Communities for Clean Water (CCW) has prepared the following comments on various groundwater permits at Los Alamos National Laboratory (LANL).


Comments on the groundwater permits were generated with substantial technical support from CCW member organization Concerned Citizens for Nuclear Safety.

Top image credit: WINR