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Delivering North America’s longest-running potable reuse program

Supporting the Upper Occoquan Service Authority for more than five decades to protect the Occoquan Reservoir and strengthen water resilience through reuse
Upper Occoquan Service Authority water reuse
Water

Image courtesy of Upper Occoquan Service Authority

 

For more than five decades, Jacobs has worked with the Upper Occoquan Service Authority (UOSA) to protect one of Northern Virginia’s most vital drinking water sources — the Occoquan Reservoir — and build water supply resilience for fast-growing communities around Washington, D.C. 

Commissioned in 1978, UOSA’s Regional Water Reclamation Plant is now the longest-running indirect potable water reuse project in North America, a pioneering model that transformed wastewater from an environmental liability into a sustainable, high-quality drinking water source. 

Our continuous relationship with UOSA — spanning planning, design, construction, commissioning, expansion and optimization since 1971 — has established a global benchmark for advanced treatment, nutrient removal and water reuse innovation.

55+ years 

Jacobs has supported UOSA since 1971

54 MGD

Current treatment capacity of the Regional Water Reclamation Plant 

1+ M people

Receive drinking water sourced from the Occoquan Reservoir 

From water quality crisis to water reuse pioneer  

In the late 1960s, rapid growth in Fairfax and Prince William Counties led to severe degradation of the Occoquan Reservoir. Eleven small secondary treatment plants discharged approximately three million gallons per day of inadequately treated effluent into the watershed, contributing to algal blooms and viral contamination that threatened water quality and aquatic life. 

Virginia regulators responded with the groundbreaking Occoquan Policy, requiring a regional solution and an unprecedented level of advanced treatment. In April 1971, Fairfax and Prince William Counties and the Cities of Manassas and Manassas Park formed UOSA to design, build and operate a state-of-the-art advanced water reclamation facility. Jacobs was selected to lead the effort, marking the beginning of our relationship that continues today. 

The original 15-mgd facility began operating nearly 5 decades ago, designed with a multi-barrier treatment approach and enhanced reliability standards that were ahead of their time. The plant has since expanded to 54 mgd, evolving alongside population growth while maintaining some of the most stringent effluent limits in the United States for nutrients and other contaminants. 

Today, highly treated reclaimed water supplements the Occoquan Reservoir, which provides drinking water for more than one million people in Northern Virginia. 

UOSA stands as the longest continuously operating indirect potable reuse facility in North America — protecting drinking water for local communities while helping offset nutrient impacts from urban growth in the watershed. 

Innovation that endures  

Over five decades, Jacobs has continuously supported UOSA in advancing treatment technologies and resource recovery strategies. Innovations have included: 

  • Advanced biological nutrient removal 
  • The use of hydrocyclones to aid sludge settleability Windrow composting followed by thermal drying to produce Class A biosolids 
  • Beneficial reuse of digester gas 
  • From its founding in 1971 through multiple plant expansions and technology upgrades, Jacobs has supported UOSA in maintaining exceptional treatment performance while adapting to regional growth and evolving regulatory requirements. The facility continues to protect the Occoquan Reservoir while providing a reliable reclaimed water source that strengthens Northern Virginia’s drinking water supply. 

  • Our work with UOSA demonstrates how long-term collaboration and engineering innovation can protect critical water resources while supporting growing communities. For more than five decades, we’ve worked together to advance a water reuse solution that safeguards the Occoquan Reservoir and strengthen regional water resilience.
    Don Forgacs
    Wastewater Project Manager.

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