Water and the Future of Prince William

There was a Town Hall meeting held at Battlefield High School on Thursday, April 28th 2022 about the changes planned in land us in the Comprehensive Plan Update and Amendments and what the impact will be on Prince William County. Below is my talk. 

image from PW Conservation Alliance

The Changes in land use proposed in the PW Digital Gateway CPA , and the 2040 Comprehensive Plan Update will effectively remove over 10,000 acres from forested, open and agricultural use and convert them to:  

• Higher density Residential: 2,400 acres  
• Village and Hamlet residential and commercial mixed: 1,500 acres
• Data center/ industrial 4,200 acres
• The remainder of the rural area will be up-zoned.

This massive rezoning will bring great wealth to the landowners- land that is worth $25,000-$50,000 would magically be worth up to $1,000,000 an acre (in the case of data centers), but these windfall profits threatens the drinking water supply for all of Prince William County and the entire Occoquan Watershed.

 

The Occoquan Watershed is the source of the groundwater that not only feeds the private and public water wells in Prince William, but also supports the rivers and streams that provide drinking water for much of northern Virginia.

The Occoquan Reservoir contains 8.5 billion gallons of water that provides 40% of the daily water supply for Fairfax Water which in turn supplies Prince William Service Authority and 350,000 residents of Prince William.

The Occoquan Watershed is 590 square miles that covers two thirds of Prince William County including the all-important headwaters of the Occoquan and Bull Run. The water in the reservoir is a reflection of its watershed, and the Occoquan watershed is the most urban watershed in the nation with Prince William planning to make it even more so.  

 

from U.S. EPA

Development in the Rural Crescent threatens the health of the Occoquan watershed and the very sustainability and affordability of the drinking water supply for Northern Virginia. When generally open rural area is developed stormwater runoff increases in quantity and velocity washing away stream banks, flooding roads and buildings carrying fertilizers, oil and grease, and road salt to the Occoquan Reservoir.

Increased development in the Bull Run and Occoquan watershed as outlined in the PW Digital Gateway CPA, the 2040 Comprehensive Plan Update will increase paved and compacted surfaces and runoff and decreased forested and agricultural land. The result will decrease groundwater recharge and increase salinity and chemical and sediment contamination in the watershed.

 

The salinity in the reservoir has been rising over time and is reaching a critical stage.  Increased population, industry and paved surfaces that need to be salted will only make it worse. The only way to remove salt from the drinking water supply is to invest billions of dollars (by increasing your water rates) in building and installing desalination equipment in the region’s water treatment plants which are not currently capable of removing salt from the source water. There is no other source of water to supply our area. The costs to add treatment lines at Fairfax Water and UOSA (because it supplies up to 40 million gallons of reclaimed water a day to the Occoquan Reservoir) to keep the Occoquan Potable is estimated to cost between $1 and $2 billion. This is a cost that will be borne by the water rate payers including the residents in Prince William County.

 

from ICPRB top sodium sources wet weather on top

Development in the watershed triggers a number of problems with storm water runoff as the primary driver, though wastewater from UOSA and septic sources also contribute to the deterioration of the water quality. The rising salt in the reservoir is primarily from watershed runoff during wet weather and reclaimed water from UOSA during dry weather.

 

Sodium concentration in the reclaimed water is higher than in outflow from the two watersheds right now and has increased. As you can see in the slide from the Occoquan Watershed Lab more than half the salt in the 40 million gallons of water a day from UOSA is of unknown source- it is suspected that blowdown from data centers’ cooling may be a significant source since that water is typically softened to protect the heat exchangers.

 

Prince William County did not even consider the impact of the proposed changes to the quality, availability and sustainability water supply as they are required to do under the Comprehensive Plan law. Before we do irreversible harm to the ecology and our regional drinking water supply, we need to look at what the impacts of planned changes will be to the water supply.

Fairfax Water has taken the unusual step to ask that Prince William County convene the Occoquan Basin Policy Board and oversee a Comprehensive Study of the proposed PW Digital Gateway CPA and the 2040 Comprehensive Plan Update to evaluate their impact on water quality and quantity in the Occoquan Reservoir before any action is taken. The cost to restore the basin and treat the water is in the billions of dollars that will be borne by us, the residents who remain- not those who get the windfall from the sale of their land and dash off with their millions.