Rivanna Water & Sewer Authority (RWSA) operates five wastewater treatment plants with a combined capacity of 15.7 million gallons per day (MGD). Wastewater flows from City of Charlottesville and or Albemarle County Service Authority's municipal collection systems to RWSA's interceptor system of pipes and pump stations to our treatment plants. Highly skilled, trained and licensed staff operates and maintain the treatment processes and regulatory compliance with our Federal/State discharge permits.

RWSA is recognized as a leader in environmental stewardship, with an impressive record of facility discharge permit compliance. RWSA must comply with Virginia Pollutant Discharge Elimination System (VPDES) permit limitations. The Virginia Department of Environmental Quality issues the discharge permit, which is reviewed and reissued every five years.

Supporting Our Community Needs

Our reputation is for not only meeting but exceeding requirements in our discharge permits, and we have initiated the costly improvements needed to meet safety regulations, ensure responsive, reliable service to our customers and protect our local streams and rivers along with the Rivanna and James Rivers and the Chesapeake Bay.

The Wastewater Treatment Process:

Treating wastewater protects human and environmental health. Without adequate wastewater treatment, there would be the potential for water borne diseases such as cholera, dysentery, and typhoid, and we would not be able to use our local waterways as recreational avenues.

When Wastewater arrives at our treatment plants, it is referred to as influent. After it is treated and returned to our local waterways, it is referred to as effluent. Effluent is generally cleaner than the waterways into which it is released.

Wastewater treatment is highly complex, involving physical, chemical, and biological processes.

There are Several Steps to Wastewater Treatment

Preliminary Treatment: Removes grit (sand), debris, and man-made objects.

Primary Treatment: Allows for the settling and flotation of organics and solids. Heavy solid particles such as food waste sink to the bottom, and lighter organics such as oil and grease float to the top. About 35% of the organics and 50% of the solids are removed.

Secondary Treatment: Uses naturally occurring microorganisms to remove additional organics and solids such as sugars, starches, proteins, detergents, and soaps.

Nutrient Removal (Proposed for construction at Moores Creek WWTP between 2009 and 2012): Eliminates the majority of phosphorus and nitrogen in the influent wastewater in order to protect the receiving streams, rivers and the Chesapeake Bay from enhancing objectionable algal growth.

Disinfection: Kills disease-causing organisms. Effluent is typically chlorinated or illuminated with ultraviolet light for disinfection. Chlorinated effluent is dechlorinated before it is released to local waterways; making is safe for aquatic life.

Recycling for a Sustainable Environment

Typically, wastewater is treated and the effluent is then returned to local waterways. Rather then dispose of the highly treated Moores Creek wastewater facility effluent, RWSA recycles a portion of this treated effluent and uses it for multiple non-drinking uses in the Moores Creek 15 MGD facility for over a 1.5 million gallons annual savings of potable drinking water. This in-plant reuse maximizes our conservation efforts and helps to preserve the existing drinking water supply and results in more effective stewardship of precious water resources.

Organic material in wastewater that is removed from primary and secondary treatment processes form what is called "biosolids". RWSA recycles 100% of our generated biosolids back to the environment. This nutrient rich organic matter is digested on RWSA's site and then is converted into compost at the McGill Environmental Systems facility in Waverly, Virginia (pdf) so that it can be safely returned to the soil as nature intended to aid in promoting vegetative plant growth. There are many beneficial uses for this compost, which meets stringent federal and state standards for safety.

RWSA also produces renewable energy from methane gas that is formed as a part of the treatment of biosolids. This renewable energy currently provides power to furnish essential compressed air to the secondary treatment process and for building heat. Following the Moores Creek WWTP construction scheduled for 2009-12, renewable energy production will be further enhanced by the generation of electricity from this gas.