McGaffey and Main Groundwater Plume

Overview

The McGaffey and Main Groundwater Plume covers 550 acres in Roswell, New Mexico and sits on the National Priorities List as a final entry. Dry cleaning businesses operating on South Main Street released perchloroethylene (PCE) and trichloroethene (TCE) into soil and groundwater. The New Mexico Environment Department found the contaminated groundwater in 1994 and connected affected residents to the public water supply. EPA added the site to the National Priorities List in 2002 and selected a cleanup plan in 2008.

Three contaminants of concern have been identified: tetrachloroethene (PCE) in soil, soil gas, and groundwater; trichloroethene (TCE) in groundwater and soil gas; and cis-1,2-dichloroethene in soil gas. PCE concentrations exceeded 10,000 micrograms per liter in monitoring wells near the 1100 block of Main Street. A contaminated groundwater plume stretches more than two miles southeast from the source area and has grown roughly 2,200 feet since 2008.

Cleanup has been underway since February 2012. Vapor intrusion mitigation systems installed at four buildings reduced indoor PCE levels from 72,000 micrograms per cubic meter down to 12.7 micrograms per cubic meter by April 2014. A soil vapor extraction system also operates on an intermittent schedule, and together these systems have removed an estimated 430 pounds of PCE. The New Mexico Office of the State Engineer put a temporary well drilling moratorium in place in May 2016 to stop new wells from being drilled in the plume area. Institutional controls also require future buildings in the source area to include vapor barriers or control systems, and property deed records note soil and soil vapor contamination.

Human exposure is currently under control, meaning no unacceptable exposure pathways have been found across the site. However, groundwater migration is not yet under control, the plume continues to expand, and physical construction of the full remedy remains incomplete. Source area groundwater remedy design was completed in 2017, with construction planned for late 2025 through early 2026. A five-year review was completed in August 2022, and the next review is estimated between August and October 2027. Long-term response action is planned to begin between April and June 2027.

Community members can get involved by contacting EPA or the New Mexico Environment Department through the site contacts. EPA and the state are currently requesting community feedback through interviews about experiences and concerns at the site. Site documents are available at the Roswell Public Library in Roswell, New Mexico, and at the EPA Region 6 office in Dallas, Texas.