PWCA Working for Sustainable Water

 In a briefing to the Board of County Supervisors in December 2024, the Occoquan Watershed Laboratory Director, Dr. Stanley Grant made it clear that emerging water quality issues are a result of the “built” environment. As we continue to develop the Occoquan Watershed we endanger the sustainability of the water supply for up to 1 million people in northern Virginia. When population  density increases, the impervious surfaces in a watershed increase. However, the increase is not linear, once the population density is reaches 100 people per square mile, the rate of increase in impervious surfaces takes off.

from S. Grant presentation

The decisions made in the update to the comprehensive plan two years ago of expanding the development areas of the county, will only serve to increase the rate of degradation of the watershed enabling  rapid sprawl development. The source water to the Occoquan Reservoir is supplied by:

• Bull Run Watershed 25%
• Occoquan River Watershed 48%
• Groundwater and other watershed 20%
• UOSA Reclamation Facility 6%

Prince William County, the Prince William Conservation Alliance (PWCA) is countering this trend with a new initiative designed to guide the county’s growth in fiscally responsible ways that protect natural resources, enhance community character, support a thriving economy. To the typical elements of “Smart Growth” they have added sustainable water since Prince William at 40% of the Occoquan Watershed remains an essential element in sustainable water for the region.

The section below is from “The 3Rs of Reaching Our Potential—Reimagine, Reinvest, Redevelop” a strategic framework to help residents, county staff, the Board of County Supervisors and other decision makers envision a smarter, more sustainable path forward for growth and development.

 

“Drinking Water - The Missing Piece to Our Smart Growth Puzzle

Smart growth often emphasizes walkable communities, protecting farmland, and preserving natural resources. But one essential resource is frequently overlooked: our drinking water.

Clean, reliable, and affordable water is foundational to any community. In Prince William County, this means protecting the Occoquan Reservoir—our region’s primary drinking water source—and preserving groundwater, which supplies 15% of county residents.

Land use decisions directly impact water quality. As we develop the watershed, increasing impervious surfaces like roads and rooftops reduces groundwater recharge and sends more polluted runoff into our streams.

Watershed management and protection must be at the core of smart growth to truly plan for a resilient future. That means concentrating development where infrastructure already exists and avoiding further expansion into the forested and rural areas that protect and relieve development pressure on our drinking water watershed. We especially want to focus protections on reservoir-adjacent lands, which is what ORPA is designed to do, and tributary headwaters, which the AAOD supports.

Data published by the Occoquan Watershed Monitoring Lab suggests that emerging water quality challenges, namely salt and PFAS have smart growth elements to their management strategy i.e. concentrate population growth near transit hubs and limit expanding development further on rural or forested lands in the Occoquan Reservoir Watershed can prevent further degradation of the watershed and the source waters for the Occoquan Reservoir.”

As you can see above, thought UOSA only supplies 6% of the water to the Occoquan Reservoir, it supplies 20% of the salt only half of which comes from households and 39% of the PFOA ( with unknown portion from households). Industrial users are discharging their wastewater to UOSA and that is extremely problematic.