LANL Proposes to Close Waste Disposal Areas

LANL Proposes to Close Waste Disposal Areas

Los Alamos National Laboratory (LANL) took initial steps in the preparation of a plan for the required clean up and closure of two legacy waste dumps. Waste has been disposed of at these sites in unlined pits, trenches and shafts since 1957. Over 10 million square feet of waste has been located there throughout operations. The closure plan covers 80 acres along the Pajarito Plateau.

The two sites, Material Disposal Area (MDA) G and L, are legacy waste sites located in Technical Area 54. MDA G opened in 1957 and until 1980 was used to dispose of all types of radioactive and hazardous waste. In 1980, it became strictly a low-level radioactive waste disposal area, although it continues to store drums of transuranic waste both above and below ground. MDA L is located west of MDA G. Its inventory is predominantly liquid solvents, which were disposed of both packaged and unpackaged.

LANL is evaluating several clean up options including removal, partial removal and cover. LANL states that they cannot remove much of the waste from the ground because it will be too difficult and pose too great a risk to worker health. The cover option is intended to prevent the contamination from being released by reducing erosion and preventing rain and snowmelt from reaching the waste and carrying contaminants to groundwater. New Mexico Environment Department (NMED), who regulate the clean up and closure, has required that LANL considers the impacts of disposal for 1000 years. However, the radionuclides, which have been disposed of there, will remain a danger to human health and the environment for millions of years.

Preliminary investigations have indicated that radioactive tritium, other radionuclides and volatile organic compounds have reached the tuff beneath the site. LANL has not drilled the required characterization wells to test the ground water beneath the site and ensure that no additional contaminants have reached it. They have used data from bore holes and field tests to estimate the extent of the migration.

Community groups are concerned that the proposed options for clean up of MDA G and L will not be adequate to protect ground water. Already, in a ground water characterization well located 500 feet east of MDA G two contaminates, pentachlorophenol and benzo(a)pyrene, have been discovered at levels above the drinking water standard.

While planning to remediate these sites, LANL will expand waste disposal at a new site within TA-54, located between MDA G and L. LANL is planning to continue burying waste in unlined pits, shafts and trenches. This site, known as Zone Four, covers about 30 acres, however only 24 are useable because it contains eight archeological sites located within its boundaries.

LANL is required to clean up these sites under the consent order, an agreement made in 2005 with NMED. LANL is requesting public comments on their proposed cleanup plan by March 15, 2007. LANL will then submit a plan to NMED. Comments can be sent by email to Lorrie Bonds Lopez at

For more information about MDA G and ground water issues click here.

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