A student researcher’s presentation at the Fallon County Commission meeting prompted a discussion among county and state environmental and public‑health officials about elevated E. coli and human fecal markers detected in local lakes.

Student Bree Strob presented multi‑year testing she did comparing Baker Lake and nearby Sandstone Lake, using 100‑milliliter water samples processed and incubated at the school laboratory. Her results showed Baker Lake’s E. coli counts were far higher than Sandstone’s; she and local environmental staff said their follow‑up tests, including metagenomics analyses that target human‑specific markers, found signals consistent with human sewage.

Why it matters: Officials said evidence of human‑source contamination raises public‑health concerns for recreational users and complicates lake management. The county’s environmental health officer and state DEQ staff discussed likely pathways — sewer leaks, past discharges from a lagoon and runoff — and emphasized the need to trace sources before adjusting management actions.

Officials’ response and next steps: Montana DEQ staff and county environmental health said they will work with the student and county staff to expand sampling in the summer months, especially during higher‑risk periods, and to test upstream sources and storm drains that could explain the human fecal marker results. DEQ described metagenomics testing as a separate, more expensive laboratory service and confirmed the county has DEQ‑supplied equipment for bacterial testing but that human‑specific assays are handled by specialized labs.

Technical context: Presenters said Sandstone Creek is partly spring fed and may flush naturally; Baker Lake relies primarily on runoff and does not have a controlled flushing gate. County testing of irrigation ponds that receive chlorinated lagoon effluent has consistently shown low bacterial levels, but metagenomics results on some Baker Lake samples have indicated a human fecal marker (HF183) signal that local wastewater officials said warrants further trace‑back sampling of sewer lines, private septic connections and storm drains.

What the county will do: County environmental health staff will plan a targeted sampling campaign — monthly in June through September, with intensified testing during historically high counts — and will compile and share results with DEQ. Officials said follow‑up actions could include targeted inspections of private sewer connections, reviewing lagoon discharge records and coordinating with the city when and where sampling indicates a probable human source.

Ending: Officials praised the student’s methodical work and invited the student to continue sampling with county and DEQ support; county staff said they would report results to the board and to the public as the sampling effort proceeds.