Kalispell presents site-specific analysis of Ashley Creek; report submitted to DEQ

Public Works Director Susie Turner and an HDR consultant summarized a multi‑year Use Attainability Analysis (UAA) for lower Ashley Creek and said the city submitted a draft UAA to DEQ on Jan. 28, 2025.

The report, Turner said, was intended to ensure “Kalispell’s future investments are based on scientific knowledge and protects the actual water quality and beneficial uses of Ashley Creek.” Turner and Ricky Schultz, a project manager with HDR, told the City Council the analysis examined water quality, geomorphology and aquatic life across an extensive reach of Ashley Creek and upstream to Smith Lake and downstream toward the Flathead River.

The studies covered five summers of sampling and included continuous monitoring equipment, nutrient diffusing substrates, algal and macroinvertebrate surveys and a geomorphology profile. Schultz said the geomorphology work showed the lower creek is low‑gradient, U‑shaped, often influenced by Flathead River backwater and lacks gravel recruitment in its lower reaches — physical traits that differ from the “western Montana wadeable stream” standard DEQ typically applies.

Schultz said a UAA is “a structured scientific assessment of a water body’s ability to achieve or meet water quality standards,” and noted the UAA process is the route for proposing site‑specific standards if a water body cannot reasonably attain existing ones. He said EPA guidance lays out six factors that can justify revised standards and that, based on the city’s data, the UAA likely meets two to four of those factors.

City staff said the draft UAA proposes two principal changes: (1) revise the mapped reach of Ashley Creek to reflect the transition from steeper upstream reaches to the lower low‑gradient segment, and (2) adopt site‑specific seasonal criteria for dissolved oxygen, a water‑temperature threshold and seasonal nutrient concentrations. Schultz and Turner said the city submitted the comprehensive draft report to DEQ on Jan. 28 and is awaiting DEQ’s formal review comments.

Council members asked how the proposed changes would affect future wastewater discharge limits and whether the site‑specific standards could reduce incentives to pursue riparian restoration and nonpoint‑source controls. Councilor Hunter asked whether using the creek’s current conditions as a baseline “takes away kind of the incentive for others along Creek to try to restore back to better conditions.” Turner and Schultz responded that UAA rulemaking is a technical, multi‑agency process that includes DEQ and EPA review and public participation, and that site‑specific criteria are intended to align regulatory expectations with the creek’s natural and existing conditions rather than to prevent voluntary restoration efforts.

Councilors also pressed staff on outreach to landowners and residents along the creek after Councilor Nunley asked whether outreach would include property owners who keep trailers or RVs along the corridor. Turner said the city plans stakeholder meetings for property owners, lake users and conservation groups and noted DEQ and EPA will hold public participation steps during rulemaking. Staff also said they would coordinate with Flathead County where private parcels lie outside city limits.

Council members raised other technical and policy questions: whether the UAA accounted for climate change impacts on temperature over decades, whether removing the city’s effluent would leave the lower creek with little summertime flow, and whether a reclassification could be used by other dischargers to relax controls. City staff said they would provide a quantified flow analysis showing the volume of effluent the wastewater treatment plant provides in summer months and reiterated that DEQ and EPA must review and approve any standard changes before they take effect.

Turner emphasized the city has invested in advanced wastewater treatment for decades and said the UAA helps the city plan future investments based on site‑specific science. Schultz said the next procedural steps are DEQ review, a planned meeting with EPA in spring, and then, if the agencies concur, a state rulemaking process that includes advisory committees and public comment. City staff estimated that multiple regulatory steps could extend several months to a year before any changes would be adopted.

No formal council action or vote occurred during the work session; the presentation was informational and staff said they will continue outreach and follow up with DEQ, EPA and the public. Turner said staff would circulate additional technical clarifications, including the requested flow quantification, to council members.