Lincoln County, Wyoming
Written by Mark Pepper, EFC Region 8 Category 2 Specialist
Lincoln County, Wyoming, borders both Idaho and Utah on the Western extreme border of Wyoming. The “Star Valley” is the northern half of the county and covers approximately 1500 square miles with four incorporated municipalities, several special taxing districts, and large areas of agricultural use and rural households. The Valley's altitude ranges from 5,600 feet (1,700 meters) to 7,000 feet (2,100 meters). It's surrounded by natural beauty, with three major Wyoming rivers—the Salt River, the Greys River, and the Snake River—meeting near Alpine Junction at Palisades Reservoir. The area's population is estimated at 11,000, with approximately 8,200 residents in municipalities and special taxing districts that own and operate water and some wastewater facilities. Only 3,400 residents are served by collection and wastewater treatment, while most utilize household septic systems. Please see the attached overview map of the Valley with “communities” highlighted and a table listing communities, calculated wastewater flows, and current treatment.
The county commission is concerned about impending rapid growth due to mineral production coming to the county area and the effect household septic leaching may have on future development, water quality, and human health. While much of the rapid growth will occur in the county's southern half (divided by a mountain range and high mountain highway pass), overflow will occur. The area will see a new nuclear reactor facility, potentially mining the world's most significant ammonia find, which will house one of the country's largest commercial solar arrays and be home to a vast rare earth find. With 20,000 population in the county currently, projections for growth indicate approximately 15,000 new residents in the next four years. Expanding current infrastructure to accommodate the new development is also part of the discussions.
Wyoming Rural Water staff were requested to engage community and county entities to determine the extent of septic flow migration water quality degradation to the primary water ways and develop a plan to address the issues. A valley-wide public meeting was held to review the problems, concerns, and regulatory information (administrative orders for MCL contamination) and gauge interest in expanding existing collection facilities and lines throughout the valley or other forms of mitigation, such as smaller “package” plants. A steering committee has been established and is currently collecting data, reviewing existing engineering reports, and conducting outreach to residents on these issues.
The steering committee was formed in February of 2024 and has had three meetings of smaller groups. During June/July, WARWS staff will assist county planners and steering committee members with compiling the data for applications to various funding sources. Monitoring wells and or plume migration modeling is anticipated as a beginning “next step” to determine the scope of issues. Once determined. Plans will be developed to address mitigation remedies. Separately, the Town of Star Valley Ranch (population about 2180) met with planning staff and WARWS staff to conduct board training and utility management. The community is interested in the potential of developing a collection and treatment system of its own. As they move through the process, connecting to other nearby municipal facilities to create an economy of scale is being discussed.