Upper Occoquan Service Authority, Virginia, USA – Operating reservoir augmentation supplying over a million people since 1978
In the late 1960s, the opening of a major highway created a suburban area convenient to people working in Washington, D.C. Population growth and development soon created water quality problems in the Occoquan Reservoir, including eutrophication, odors, and dense algal growth. This degradation was traced to 11 small underperforming community wastewater treatment plants discharging into the reservoir.
The Upper Occoquan Service Authority (UOSA) was formed in 1971 and in 1978 completed construction of a state-of-the-art advanced water reclamation plant to replace the underperforming facilities and recharge the reservoir with high quality reclaimed water. In a series of expansions reflecting increasing public confidence in indirect reuse, product water quality, and overall plant reliability, the initial fifteen million gallons (57 million litres) per day capacity was increased to 27, 32, and then 54 million gallons (102, 121, and 204 million litres) per day.
The plant has continually met all standards for reliability and water quality. The discharges from the plant are a source of drinking water supply for over two million people. After a half-century of highly successful operations, Upper Occoquan Service Authority reclaimed water is an increasingly important component of the drinking water supply strategy for the Washington metropolitan area.
