Water Resource Recovery Facility (WRRF)

Built to meet today’s demands while protecting local water resources for generations to come.

Meeting Big Sky’s Growing Needs

Big Sky’s continued growth has increased the community’s need for reliable, sustainable wastewater treatment. The Big Sky County Water & Sewer District operates a state-of-the-art Water Resource Recovery Facility (WRRF) .

The facility produces clean, high-quality water that is safely reused or returned to the environment – supporting community growth, preserving natural resources, and safeguarding the Gallatin River.

Big Sky Treatment Facility

Treatment Capacity

910,000 gallons per day

Treatment Processes

Biological nutrient removal, membrane filtration, advanced oxidation (AOP).

Effluent Quality

Class A-1 (exceeds Montana DEQ drinking water standards)

Environmental Impact

75% reduction in nitrogen, 95% reduction in phosphorous.

Community Benefit

Supports 600 new SFEs for workforce housing.

Big Sky Treatment Facility

How the WRRF Works

The WRRF uses a modern, multi-step treatment process that includes biological nutrient removal, membrane filtration, and advanced oxidation (ozonation or AOP). These processes remove nutrients, solids, and contaminants to produce Class A-1 effluent, which exceeds Montana Department of Environmental Quality (DEQ) drinking water standards.

No treatment chemicals are discharged from the facility. The result is an exceptionally clean, clear effluent suitable for beneficial reuse and groundwater recharge through infiltration galleries.

Big Sky Treatment Facility

A Needed Upgrade

Prior to the expansion, the original treatment facility was nearing its rated capacity, and Big Sky’s continued growth meant that higher-quality effluent and greater capacity were needed to support development and protect local water resources.

The WRRF expansion increased average treatment capacity from 600,000 gallons to 910,000 gallons per day. It also ensures the District can support an additional 500 Single Family Equivalents (SFEs) dedicated to workforce housing—helping to address one of the community’s most critical needs.

Big Sky Treatment Facility

Environmental Benefits

The WRRF was designed with sustainability and environmental protection in mind. It reduces nitrogen by approximately 75% and phosphorous by approximately 95%, helping prevent algal blooms and maintaining water quality in the Gallatin River and its tributaries.

The system also improves groundwater protection, particularly in the Canyon Area, where septic drain fields have been phased out and replaced with collection and treatment through the WRRF. These improvements safeguard drinking water quality and reduce environmental impacts associated with untreated or inadequately treated wastewater.

An Outside Look of the WRRF

Responsible Investment in Infrastructure

The total cost of the WRRF expansion and related infrastructure was approximately $47 million, funded through a combination of resort tax revenue, State Revolving Fund (SRF) loans, and existing District revenues. This community investment ensures Big Sky’s wastewater system will remain resilient, efficient, and compliant with regulatory standards well into the future.

A Sustainable Future for Big Sky

The Water Resource Recovery Facility represents Big Sky’s commitment to environmental stewardship, innovation, and long-term community planning. By transforming wastewater into a clean, reusable resource, the WRRF not only supports growth—it protects what makes Big Sky special: our rivers, mountains, and quality of life.