Water, Wastewater & Stormwater Systems

Water & Wastewater Systems

Certified operators and laboratory personnel oversee the entire Water and Wastewater Systems and processes 24 hours per day, every day of the year. This steadfast commitment ensures that our systems always exceed the requirements of the Federal Safe Drinking Water Act (SDWA) and the Administrative Rules of Montana (ARM).

The Public Works Department staffs a State Certified Laboratory responsible for testing and monitoring the water quality. Testing is performed throughout the entire treatment and reclamation processes, as well as testing while in the distribution system. We perform many hundreds of tests and analysis monthly to ensure that we deliver a superior quality product for your drinking water, and to that the reclaimed water causes no harm to our environment.


Each month, we submit a detailed report to the Montana Department of Environmental Quality documenting our compliance with the Federal Safe Drinking Water Act and the Administrative Rules of Montana. We publish a monthly water quality report for the Yellowstone River, which is our water source, and for our finished drinking water product.

Access the current water quality data:

  1. Water Treatment
  2. Wastewater Reclamation
  3. Meters, Mains & Hydrants
  4. Ditches & Drains
  5. Fats, Oils & Grease

Water Treatment Plant HistoryIMG_2548

In 1885, several prominent businessmen formed the Billings Water Power Company and began construction of a waterworks facility. At that time, the waterworks facility housed an 80-horsepower waterwheel to generate electricity for the City and a 1.25-million-gallon-a-day (MGD) pump that delivered an estimated 150,000 gallons per day of untreated water to the City through 5.25 miles of distribution pipe.

The City of Billings purchased the waterworks in 1915 for $315,000. The plant has undergone many upgrades and expansions and now provides complete conventional treatment for up to 60 MGD.

Our Water Sourceriver 1

The Yellowstone River, a high-quality surface water source and the longest free-flowing river in the country, is the source of our drinking water.

On its 640-mile journey from Yellowstone Park, the water picks up contaminants, such as microorganisms, organic and inorganic contaminants, suspended solids and trace contaminants from upstream agricultural and industrial activities. The City’s water treatment facility plays a critical role in removing these contaminants to provide us with safe, high-quality drinking water.

Water Treatment ProcessP1020519 (002)

The Gerald D. Underwood Water Treatment Plant has two raw water intake structures:

  • Intake Number 1 is a side channel diversion and is the primary intake.
  • Intake Number 2 is a brick structure in the middle of the river and is designed primarily for emergency use.

Water then goes through four basic steps.

  • Step One: Coagulation This process uses chemicals such as polymers and polyaluminum chloride to alter the electrical charge on small suspended particles so they to become "sticky".
  • Step Two: Flocculation Next, water is mixed with just enough energy to cause the "sticky" particles to clump together and form larger particles with enough mass to settle out of the water.
  • Step Three: Sedimentation The large clumps of particles (floc) settle to the bottom of the basin. The plant has both a primary settling basin and a finishing basin. This step typically removes about 95% of the suspended solids in the water.
  • Step Four: Disinfection / Filtration The plant uses chlorine to inactivate the health risks associated with microorganisms. The chlorinated water is filtered through 12 dual media filters. These filters are made up of sand and anthracite coal that capture any particles remaining after coagulation, flocculation and sedimentation.

Plant Operations

The Control Room is the control center for monitoring and controlling the entire plant treatment process. It also monitors and controls the pumps and reservoirs in the distribution system. This is accomplished by using computers, sensors, monitors, radio and fiber optic communication and specialized software programming that are tied to a SCADA system (Supervisory Control and Data Acquisition System).

The plant has two, five-million gallon reservoirs that store the treated water long enough for the chlorine to do its job while also providing system storage.

Water treated at the plant must be pumped into the distribution system. The plant’s High Service Pump Station, made up of 12 pumps with different capacities, is responsible for delivering water into the distribution system.

Stormwater Systems

What is Stormwater?Combination-Storm-Water-Inlet 1

Typical Stormwater found in the City’s storm drain system is water from precipitation that flows across the ground and pavement when it rains, snows or when ice melts. The water seeps into the ground or drains into what we call storm sewers. These are the drains you see at street corners or at low points on the sides of your streets.Collectively, the draining water is called stormwater runoff and is a concern to us in commercial and industrial sites, as well as your neighborhood, because of the pollutants it carries. 
Stormwater is not treated once it enters the city storm sewers, therefore all of the untreated stormwater flows directly into the Yellowstone River.

Yellowstone River Intakes and Outfalls
Stormwater System Map
river 1
According to the 1996 National Water Quality Inventory, stormwater runoff is a leading source of water pollution. Stormwater runoff can harm surface waters such as rivers, lakes, and streams which in turn cause or contribute to water quality standards being exceeded.Stormwater runoff can change natural hydrologic patterns, accelerate stream flows, destroy aquatic habitats, and elevate pollutant concentrations and loadings. Development substantially increases impervious surfaces thereby increasing runoff from city streets, driveways, parking lots, and sidewalks, on which pollutants from human activities settle.
Common pollutants in runoff include pesticides, fertilizers, oils, metals, pathogens, salt, sediment, litter and other debris are transported via stormwater and discharged - untreated - to water resources through storm sewer systems.

  1. Regulations & Permits
  2. Shiloh Conservation Area
  3. Illicit discharge


The City of Billings is a Municipal Separate Storm Sewer System (MS4) co-permittee with Montana Department of Transportation.  The City also has a MS4 partnership with Yellowstone County.  The MS4 General Permit requires permittees to develop, implement, and enforce a Stormwater Management Program (SWMP). The SWMP shall be designed to reduce the discharge of pollutants from the permitted MS4 to the Maximum Extent Practicable (MEP), to protect water quality, and satisfy the appropriate water quality requirements of the Montana Water Quality Act. The SWMP must include Best Management Practices (BMP), control techniques, good standard engineering practices, and other provision necessary to control pollutants.

The City of Billings Stormwater Program consists of BMPs from the following categories:baby geese from ospreynest 002 (2).jpg

  • Construction Runoff Management
  • Post Construction Stormwater Management for New and Redevelopment
  • Public Education and Outreach
  • Public Participation and Involvement
  • Illicit Discharge Detection and Elimination
  • Pollution Prevention for Municipal Operations

MS4 General Permit