Lawmakers discuss requiring groundwater baseline testing before some limited mining operations

A proposal to give the Department of Environmental Quality (DEQ) explicit authority to require groundwater baseline monitoring before some limited mining operations (LMOs) drew detailed technical discussion at a Minerals, Business & Economic Development Committee hearing.

Representative Steve Harshman introduced the concept as a targeted tool to protect private wells and municipal water supplies in areas where LMOs are proposed near shallow groundwater or sensitive aquifers. He described recent local concern in the Casper area as an impetus: residents there learned of excavation activity only when it began and raised questions about possible effects on shallow wells.

What was proposed: Representative Harshman asked the committee to add language allowing the DEQ to require water quality testing before an LMO commences when the department identifies a potential risk to groundwater. DEQ's Water Quality Division administrator, Jennifer Zigmund, told the committee that the agency supports the concept of baseline sampling and has established programs and experience to perform or supervise such monitoring, but that program implementation raises resource, rulemaking and operational questions.

DEQ technical position and resource note: Administrator Zigmund said baseline data are important to determine…