Contacts

Environmental Communication & Public Involvement
P.O. Box 1663
MS J591
Los Alamos, NM 87545
Phone: 505-667-0216
FAX: 505-665-1812
envoutreach@lanl.gov
Site Index

Drilling Fluids

Los Alamos National Laboratory (LANL) is located in north-central New Mexico and covers 37 square miles of the Pajarito Plateau in a series of finger-like mesas separated by deep canyons with perennial and intermittent streams running from west to east.

Environmental Remediation & Surveillance Program

The Department of Energy’s (DOE) environmental remediation efforts began in 1989. The Environmental Program is LANL’s contribution to a nationwide DOE program for cleanup and remediation. LANL investigates the presence of chemical and radioactive waste resulting from past LANL operations and cleans up and restores such sites to protect human health and the environment.

Groundwater Monitoring at LANL

The communities of Los Alamos, Española, Santa Fe, and neighboring pueblos obtain drinking water from the regional groundwater aquifer. LANL monitors the groundwater beneath the Pajarito Plateau to ensure that contamination from LANL operations does not impact human or ecosystem health. Currently, LANL monitors approximately 225 sampling locations for the quality of groundwater. These locations include deep groundwater wells (reaching 600 to 2,000 ft below the ground) and springs. In addition, LANL monitors shallow and intermediate groundwater wells (40 to 600 ft deep). LANL also monitors the drinking water wells of the neighboring communities.

The two types of regional groundwater monitoring wells at LANL are single screen and multiscreen. The screen is the portion of the well where water enters from the surrounding rock formations. Single-screen wells produce water at only one location below ground level. Multiscreen wells can have two to nine screens below ground level.

Groundwater Characterization Program

From 1998 to 2005, LANL expanded its groundwater well network as part of an effort to understand the groundwater systems. The two major goals were to characterize the groundwater system and to design an appropriate groundwater monitoring network. A total of 33 deep groundwater wells were drilled under an agreement (called the Hydrogeologic Workplan) between DOE, the University of California, and the New Mexico Environment Department (NMED). Deep well locations were chosen to identify

important geologic zones
the location and depth of groundwater
the presence of contaminants in different groundwater zones
the direction of water flow (and thus the flow of contaminants)

All parties to the agreement understood that when characterization activities were complete, not all wells would be required for an appropriate monitoring network.

Groundwater Well Construction

Because of the complex nature of the geology, drilling to the regional aquifer of the Pajarito Plateau requires the use of drilling fluids, such as foams or drilling muds. For example, drilling fluids keep the boreholes from collapsing during the tests needed to select the specific depth for a characterization well.

Well development is a process at the end of well construction whereby the drilling fluids are scrubbed out of the wells. High-pressure water and specially designed scrubbing tools are used to remove drilling fluids. In some wells at LANL, the drilling fluids were not completely removed during well development.

Solutions to Problems Caused by Residual Drilling Fluids

Leftover drilling fluids can mask the presence of some, but not all, LANL-derived contaminants. Sixteen of the 33 characterization wells show some impacts from residual drilling fluids. LANL is planning corrective actions to ensure that sampling from all wells in the monitoring network can accurately identify contamination. These actions will include

creating a pilot test for redeveloping two groundwater wells
evaluating the pilot test results
developing corrective actions for the remaining wells

Depending on the pilot test results, corrective actions might include redeveloping wells, replacing multiple-screen wells with single-screen wells, and/or replacing wells. The pilot test was completed during the summer and fall of 2006. The proposed corrective actions will be submitted to NMED for approval.

Community Involvement, Information and Assistance

LANL is committed to gathering community input, involvement, and assistance in our groundwater monitoring program. Presentations and other communications venues on groundwater monitoring are available to interested persons.

Phone: (505) 667-0216
FAX: (505) 665-1812
Email: envoutreach@lanl.gov

Data & Documents

Public Notices

Review of November 2008 Groundwater Data