Commission to revisit septic variance at 4473 Lower Gros Ventre

Teton County commissioners are set to decide whether a 0.25 acre lot at 4473 Lower Gros Ventre Road can use an on site absorption system even though county rules say those systems should be on parcels of at least 2 acres agenda. The permit request, SWF2026-0005, would serve a new residence on a family-divided parcel in Kelly. A county staff report says the application was continued in June after discussion of nitrates trending upward in nearby wells, including the Kelly School Well, and because the lot sits within a groundwater protection area identified in the county water quality plan staff report.

Before Monday's vote, the key change is the applicant's revised design. County Engineer John Kemp now recommends approval after the applicant added an Advantex treatment unit and ultraviolet treatment, writing that replacing an unknown aging system with advanced treatment would be less of a public health risk than existing conditions. Staff still says two variance findings technically cannot be made because the 0.25 acre lot was created through a 2025 family subdivision, but the report concludes the upgraded system would still improve wastewater treatment on a crowded stretch of Lower Gros Ventre Road staff report.