Chromium Plume

Ensure contamination doesn’t threaten human and environmental health

Chromium Plume History

From 1956 to 1972, chromium-contaminated water from cooling towers was periodically released from the cooling towers into Sandia Canyon. Chromium was commonly used as a corrosion inhibitor. The water flowed from the power plant down Sandia Canyon as surface water, penetrated the underlying rock layers, and in time seeped into the regional aquifer beneath Sandia and Mortandad canyons. LANL ceased releasing chromium-contaminated water in 1972.

contaminant of concern:

Hexavalent Chromium


Control migration of the chromium plume and reduce the plume footprint, while investigating the final remedy

Chromium Interim Measure at a Glance

An interim measure is a set of actions that have a high probability of meeting environmental protection goals until a final remedy is  implemented. In the case of the chromium plume, a combination of extraction, treatment, and injection is being used to control plume migration and hold it within the LANL boundary.

Why it’s needed 

The Interim Measure, approved by the New Mexico Environment Department, is needed to mitigate plume growth.

  What it is

The Interim Measure consists of extraction and injection wells, a centrally located treatment system, and piping and infrastructure tying it all together.

HOw it works

Contaminated water is extracted and treated using ion-exchange technology. The treated water is then injected along the plume edge. Chromium concentrations will be reduced at the plume edge and the plume footprint will be reduced in size.

What’s Next

The Interim Measure will take place over the next several years until a final remedy has been identified and is being implemented. 

Fall 2020 Status

  • To date, Interim Measure activities along the southern portion of the plume have established a new 50-ppb plume edge approximately 350 feet upgradient from where it was at the start of the project.
  • Implementing full scale operation of the IM system
  • Evaluating final remedy options

Final Remedy

DOE’s Environmental Management Los Alamos Field Office and its contractor, N3B, are investigating potential remedy options for remediating the plume. Public participation is integral to the decision-making process. 

By the Numbers

parts per billion

New Mexico Groundwater standard for chromium


Approximate time it will take the Interim Measure to fully control the plume within the LANL boundary


Distance (as measured at the surface) of the plume from the Rio Grande


Number of monitoring, extraction and injection wells installed in and around the plume


Amount of chromium contamination in
Los Alamos County drinking water wells


Depth of the regional aquifer. Chromium is located within the top 100 feet of the  aquifer.


long x 1/2 mile wide x 50-75 ft. thick > 50ppb

Approximate size of the chromium plume


Approximate distance from the plume edge to the  nearest Los Alamos County groundwater well

Chromium Plume Map


1200 Trinity Drive
Suite 150
Los Alamos, NM 87544


(505) 257-7690


Contact N3B

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