Water Treatment Plant History
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 Source
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 Process
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 a two-stage disinfection plan. Chlorine is used 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. The secondary disinfection technology is an ultraviolet (UV) light system, which provides an extra layer of protection by neutralizing any chlorine-resistant microorganisms. After the processed water leaves the plant, a chlorine residual is maintained throughout the distributed water and pipes of the city as a safeguard against the possibility of any subsequent microbial contamination.
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.