Water Treatment Plants and Process

Beaker of Water

 

Rivanna is dedicated to providing reliable, clean, safe drinking water for our community, now and in the future.

But before it gets to your house, it takes highly skilled, trained, and licensed professionals working around the clock to ensure things like consistent pressure, high-quality taste, and reliability.

Brian at the South Fork Water Treatment Plant Photo/Andrew Shurtleff

Brian at the South Rivanna Water Treatment Plant (photo:Andrew Shurtleff)

We operate five drinking water treatment plants with a combined nominal capacity of 23.0 million gallons per day (MGD).

Crozet Water Treatment Plant
North Rivanna Water Treatment Plant
Observatory Water Treatment Plant
Scottsville Water Treatment Plant
South Rivanna Water Treatment Plant

The effective maximum day operating capacity, taking into account operating goals and system constraints, is 18.7 MGD. The safe yield of our water supply is currently estimated at 19 MGD.  Through our five treated water pump stations and 67 miles of water transmission pipes water flows to the City of Charlottesville and/or the Albemarle County Service Authority’s municipal water distribution systems.

The Rivanna Water and Sewer Authority operations at the South Fork facility in Charlottesville, Va. . Photo/Andrew Shurtleff

Konrad and Andrea taking water samples (photo: Andrew Shurtleff)

Water Sources
Raw water from our reservoirs and rivers is pumped into the water treatment plants.

Coagulation/Flocculation
Once it arrives at the plant, the water is treated with coagulant, the pH is adjusted and water is rapidly mixed together to help disperse the coagulant. After the rapid mixing process, the water flows into flocculation basins, where the flow of water is slowed and slowly mixed so that the particulates stick together to form bigger particles called floc.

Sedimentation
Next, the water flows into sedimentation basins, where the heavy floc particles sink to the bottom and are removed.

Filtration
The water flows through large filters made of sand and anthracite coal. Filtration removes particles and microorganisms.

Adsorption
By the end of 2017 all of our treatment plants will use Granular Activated Carbon (GAC) adsorption, a gold standard when it comes to water treatment to further increase our water quality.

Monitoring oxygen levels at South Fork Reservoir Photo/Andrew Shurtleff

Monitoring oxygen levels at South Fork Rivanna Reservoir (photo: Andrew Shurtleff)

Disinfection
We use chlorine to disinfect the water, and a residual level of chlorine is maintained throughout the distribution system as a protective barrier again microbial contamination.

Final Treatment
After chlorine disinfection, the pH of the water is adjusted and a corrosion inhibitor is added to minimize corrosion of the distribution system, and a low level of fluoride (0.7 mg/L, or ppm) is added to support good dental health.