Area C

Area C, north of Pajarito Road near TA-50, became inactive April 8, 1974. Its history of use covers 26 years. There are seven pits within the area, one of which was reserved exclusively for the disposal of non-radioactive hazardous chemical wastes and 108 shafts; none of which are greater than 1m (3ft) in diameter and 7.6m (25ft) deep. Area C is the first burial ground for which detailed records were kept. Few Studies related to environmental monitoring have been conducted in Area C.

The history of Area C extends from may 7, 1948, the date the first pit was started, through April 18, 1974, the date the last shaft was filled and plugged with concrete. It is sometimes felt that the the last routine  radioactive contaminated waste placed in area C, December 1958, marks the closing of area C and the opening  of Area G. Neither idea is true. Area G pits had received non routine radioactive waste before that date and area C pits continued to receive non routine radioactive contained waste until Pit 6 was filled august 959 and Pit 5 was filled November or December 1964. Since quarterly and annual reports on solid radioactive waste disposal fail to mention Area C after 1968, it can be assumed that the area was not in regular use pats that time. The plugins of the last area C shaft, shaft 89, On April 1974, marked the formal closing of the area.

Type of Waste

During the pit history of Area C, hazardous chemicals and unconfined classified materials were buried with radioactive contaminated materials.

Hazardous Chemical Area in Area C

As pit use was phasing out in area C and beginning in area G, the idea of separate disposal for hazardous nonradioactive chemicals (which were responsible through the years for many fires in the disposal area) was accepted.

Potential environmental impacts:

Lies near Ten-Site Canyon New Mexico Environment Department's (NMED) Hazardous and Radioactive Material Bureau (HRMB) ranks this MDA as an area with a high probability of contaminant mobilization and a moderate to high potential of release to the groundwater.


Rogers, Margaret Anne, History and Environmental Setting of Los Alamos Scientific Laboratory Near- Surface Land Disposal Facilities for Radioactive Wastes (Areas A, B, C, D, E, F, G, and T).
June 1977.


Support COMPREHENSIVE CLEANUP at Area C – Your Comments Needed!

Extended 2-Page Sample Comments available now! Download here:

We need your help to support the State’s mandate to excavate wastes instead of leaving them in place.

The New Mexico Environment Department (NMED) has rejected the Los Alamos National Laboratory’s (LANL’s) plans for so-called cleanup through “cap and cover.” LANL’s plan would leave existing radioactive and hazardous wastes uncharacterized and forever buried in unlined pits and trenches as a permanent threat to groundwater. At issue is remediation of the Lab’s “Material Disposal Area C” waste dump that has 7 pits and 108 shafts of radioactive and hazardous wastes.

This mandate will help maximize protection of human health and the environment and ensure that our critical drinking water resources are permanently protected.

Any person who wishes to comment on the proposed Statement of Basis should submit written comments, along with their name and address, to the NMED Hazardous Waste Bureau, 2905 Rodeo Park Drive, Building 1, Santa Fe, New Mexico, 87505-6303

or by email to [email protected].

Only written comments received by 5:00 p.m. MDT, November 6, 2023, will be considered by NMED in making a final decision.

Read the Area C NWNM Press Release

Read our 1-PAGE Sample Comments

Read our 2-PAGE Sample Comments

Download our 1-PAGE Sample Comments to use on your own:

Download our 2-PAGE Sample Comments to use on your own:

Important document links from the NMED page – (scroll down to Material Disposal Area (MDA) C, SWMU 50-009, Remediation, September 7, 2023)
Includes – Public Notice,
September 7, 2023-NMED Statement of Basis MDA C
June 30, 2021-DOE Corrective Measures Evaluation Rev. 1 for MDA C

Read the Santa Fe New Mexican article –
State tells feds to excavate LANL waste pit at $805M cost
By Scott Wyland, Sep 18, 2023

Documents & Resources

The Vapor Plume at Material Disposal Area C in Relation to Pajarito Corridor Facilities