The New Mexico Environment Department (NMED) presented its initial findings and next steps for investigating and remediating groundwater contamination at the San Juan Generating Station to the Radioactive and Hazardous Materials Committee.

NMED officials said the agency has completed a gap analysis, hired Jacobs Engineering to help characterize contamination and installed six new groundwater monitoring wells near discharge locations. Paul Chamberlain, with NMED’s Groundwater Quality Bureau, told lawmakers the wells are “nested” (paired shallow and deep screens) to capture vertical differences in groundwater contamination and to avoid creating cross-contamination paths.

Why it matters: the generating station and associated mine and treatment areas have active discharge permits; NMED said three discharge permits (DP-306, DP-1327 and DP-1843) remain in effect and that permit conditions and financial assurance will be used to require operator-funded remediation where appropriate. NMED noted that its state groundwater-protection rules allow it to require permit modifications and additional corrective action when monitors show problems.

What NMED has done so far: agency staff reviewed historical groundwater data, inspected potential contamination sources, and developed a work plan to fill information gaps. Jacobs Engineering completed a gap analysis in June; NMED said the analysis showed a need for upstream background wells and additional characterization to distinguish naturally occurring constituents from contamination related to plant operations.

Monitoring and modeling: NMED said it has constructed an initial 3-D model combining historical data and new well results to show how concentrations have shifted over time; modelling will be used to test remediation scenarios and to prioritize targeted cleanup subsites. The department added that some existing remediation features, such as the Shumway recovery system, remain necessary while flows and water-treatment needs persist.

Public process and schedule: NMED told the committee it has held public outreach and opened a public comment period; a follow-up report and further public meetings are planned in roughly a year. The department reported approximately $170,000 of legislative funds remaining on hand as of June 30, 2025, and said additional funding will be needed for the next phase of site characterization and remedial design.

Permits and enforcement: discharge permits are renewed on five-year cycles, but NMED emphasized that permits can be modified sooner if monitoring shows an unacceptable impact. NMED said it would pursue operator-funded corrective action using existing permitting authority and financial-assurance mechanisms, and that the agency can require additional financial assurance if needed.

Ending: NMED said the work is ongoing and emphasized the department’s preference to require PNM (the former operator) or other responsible parties to fund abatement. Officials asked legislators to consider continued support for characterization and oversight funding so the agency can complete the next round of monitoring, modeling and cleanup planning.