What’s in the Wells of Prince William County 2026

Earlier this month the well owners who participated in the 2026 Prince William County Well Water Clinic received their results by email. Below you can see the summary of what was found in the 70-water analyses performed (this was the smallest group in several years). VA Tech tested for the naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion. These are the most common contaminants that affect our drinking water wells. Also, this year they expanded their analysis to additional metal contaminants from plumbing sources and additional contaminants with health concerns.

To determine if treatment is necessary, water test results should be compared to a standard-usually the U.S.EPA Safe Drinking Water Act (SDW) limits. Though private wells are not regulated by the U.S. Environmental Protection Agency (EPA) or the Safe Drinking Water Act, the SDW act has primary and secondary drinking water standards that we use for comparison. Primary standards are ones that can impact health and from the tested substances include coliform bacteria, E. coli bacteria, nitrate, lead, and arsenic. Secondary standards impact taste or the perceived quality of the water. Then there are the substances with a health reference level (HAL) below which health impacts are not anticipated and LHA a level of contamination that if consumed over a lifetime may have health impacts.

Just because your water appears clear does not mean it is safe to drink. The 2026 Prince William County water clinic found that 25.7% of the wells tested PRESENT for coliform bacteria. This is higher than last year. Coliform bacteria are not a health threat itself; it is used to indicate other bacteria that may be present and identify that a well is not properly sealed from surface bacteria. The federal standard for coliform bacteria is zero, but the federal standard allows that up to 5% of samples can test positive for coliform during a month.

Three of the 18 bacteria contaminated wells tested positive for E coli. Fecal coliform and E. coli are bacteria whose presence indicates that the water is contaminated with human or animal wastes. Disease-causing microbes (pathogens) in these wastes can cause diarrhea, cramps, nausea, headaches, or other symptoms. These pathogens may pose a special health risk for infants, young children, and those with compromised immune systems. However, people can drink water contaminated with fecal bacteria and not notice.

If your well is contaminated with coliform but not fecal coliform or E. coli, then you have a nuisance bacteria problem, and the source may be infiltration from the surface from rain or snow melt. Typical causes are improperly sealed well cap, well repairs performed without disinfecting or adequately disinfecting the well, failed grouting or surface drainage to the well. Very low levels of coliform (1-5 MPN) may appear in an older well during extremely wet springs.

If your well was found to have coliform bacteria present you should shock chlorinate the well (according to the procedure from VA Tech), repack the soil around the well pipe to flow away from the well and replace the well cap. Then after at least two weeks and the next big rainstorm retest the well for coliform. If coliform bacteria is still present then a long-term treatment should be implemented: using UV light, ozonation, or chlorine for continuous disinfection. These systems can cost up to $2,000 installed (maybe more with recent price increases).

If you have fecal coliform in the well or E. coli, your well is being impacted by human or animal waste, and you are drinking diluted sewage. This year 4.3% of the wells tested were found to have E. coli present. If there is not a nearby animal waste composting facility, then you are probably drinking water from a failed septic system- yours or your nearest neighbors or in some areas a leaking sewer line. To solve this problem, you need to fix or replace the septic system that is causing contamination, replace the well or install a disinfection and micro filtration or reverse osmosis system. Giardia or Cryptosporidium are two microscopic parasites that can be found in groundwater that has been impacted by surface water or sewage. Both parasites produce cysts that cause illness and sometimes death. Chlorine can work against Giardia but not Cryptosporidium. Ultraviolet (UV) light works against both Giardia and Cryptosporidium so it is the preferred method of treating this problem.

The failing septic systems can often be identified by using tracer dyes. While continuous disinfection will work to protect you from fecal bacteria and E. coli, be aware that if your well is being impacted by a septic system, then the well water might also have present traces of all the chemicals and substances that get poured down the drain. Long term treatment for disinfection and micro-filtration should be implemented: using UV light, ozonation, or chlorine for continuous disinfection, carbon filtration, and anything that is used for drinking should be further treated with a reverse osmosis systems or micro membrane system both work by using pressure to force water through a semi-permeable membrane. Large quantities of wastewater are produced by reverse osmosis systems and need to bypass the septic system, or they will overwhelm that system creating more groundwater problems. Reverse osmosis systems produce water very slowly, a pressurized storage tank and special faucet need to be installed so that water is available to meet the demand for drinking and cooking.

Nitrate can contaminate well water from fertilizer use; leaking from septic tanks, sewage and erosion of natural deposits. None of the wells in our group of 70 samples had nitrate levels above the MCL. The average level of nitrates was under 2 mg/L. The regulatory limit for nitrate in public drinking water supplies, 10 mg/L, was set to protect against infant methemoglobinemia, but other health effects were not considered and are emerging as problems. Nitrate in a well tends to climb slowly over the years if the septic systems do not have at least 3 acres between them. Based on a study done years ago in Dutchess County NY at least 3 acres are necessary to naturally treat the nitrate.

Dr. Mary Ward of the Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute has lead several important studies comparing all the research on the health impacts from exposure to nitrate in water. The first review was of studies published before 2005. In 2018 Dr. Ward was lead author on a review of more than 30 epidemiologic studies on drinking water nitrate and health outcomes. If your nitrate-N levels are climbing, you might want to read Dr. Ward’s work. There are AOSS systems designed to remove nitrate. These are very expensive (think new car expensive.)

This year they found 2 of homes had first draw lead levels above the SDWA maximum contaminant level of 0.01 Mg/L. After flushing the tap for at least one minute none of the homes had lead levels above the 0.1 mg/L level; however, many scientists do not believe that any level of lead is safe to drink over an extended period of time. Often homes that have elevated lead in the first draw, have lower pH values. Corrosive water is the primary risk for lead in well water. However, over time water with a neutral pH could dissolve the coating on galvanized iron, in brass well components and plumbing fixtures.

Houses built before 1988 when the ban on lead went into effect and have low pH water typically have higher lead concentrations. Lead leaches into water primarily as a result of corrosion of plumbing and components in the well itself but can also result from flaking of scale from brass fittings and well components. Corrosion control techniques such as adjusting pH or alkalinity that are commonly used to neutralize aggressive water will not work in to reduce lead being leached from well components. For most instances, though, a neutralizing filter and lead removing activated carbon filters can be used to remove lead leaching from plumbing pipes, solder and fixtures. Recently, some home water treatment companies are offering home treatment systems that neutralize the water and add orthophosphate other phosphate solution to coat the piping to prevent further corrosion of metal pipes. It should work if maintained. This type of solution is used in public water supplies. I have no experience with this type of home system and am not aware of any testing.

Iron and manganese are naturally occurring elements commonly found in groundwater in this part of the country. Seven of the wells tested exceed the iron standard and 5 exceeded the manganese standard. At naturally occurring levels iron and manganese do not present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing and discolored water. The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese can be detected by taste, smell, or appearance. In addition, some types of bacteria react with soluble forms of iron and manganese and form persistent bacterial contamination in a well, water system and any treatment systems. These organisms change the iron and manganese from a soluble form into a less black or reddish brown gelatinous material (slime). Masses of this slime, iron, and/or manganese can clog plumbing and water treatment equipment even in extreme circumstances clog up a well pump.

All systems of removing iron and manganese essentially involve oxidation of the soluble form or killing and removal of the iron bacteria. When the total combined iron and manganese concentration is less than 15 mg/l, an oxidizing filter is the recommended solution. (Iron bacteria, hydrogen sulfide and tannins can also be removed with pre-chlorination.) An oxidizing filter supplies oxygen to convert ferrous iron into a solid form which can be filtered out of the water. Higher concentrations of iron and manganese can be treated with an aeration and filtration system. This system is not effective on water with iron/ manganese bacteria but is very effective on soluble iron and manganese, so you need to do further testing to determine what type of iron/manganese you have before you install a treatment system. Newer iron filters have an option to add an ozone generator to kill reducing bacteria.  Water softeners can remove low levels of iron and manganese and are widely sold for this purpose because they are very profitable but are now being banned in some locations due to rising sodium and chloride levels, what is known as inland salinization. Increasing salinization of our water resources is a growing problem in our region. Also, water softeners are easily clogged by iron bacteria.

Chemical oxidation can be used to remove high levels of dissolved or oxidized iron and manganese as well as treat the presence of iron/manganese (or even sulfur) bacteria. The system consists of a small pump that puts an oxidizing agent into the water before the pressure tank. The water will need about 20 minutes for oxidation to take place so treating before a holding tank or pressure tank is a must. After the solid particles have formed the water is filtered. The best oxidizing agents are chlorine or hydrogen peroxide. If chlorine is used, an activated carbon filter is often used to finish the water and remove the chlorine taste. The holding tank or pressure tank will have to be cleaned regularly to remove any settled particles.

The pH of water is a measure of the acidity or alkalinity. The pH is a logarithmic scale from 0 – 14 with 1 being very acidic and 14 very alkaline. Drinking water should be between 6.5 and 8.5. For reference and to put this into perspective, coffee has a pH of around 5 and salt water has a pH of around 9. Corrosive water, sometimes also called aggressive water is typically water with a low pH. (Alkaline water can also be corrosive.) Low pH water can corrode metal plumbing fixtures causing lead and copper to leach into the water and causing pitting and leaks in the plumbing system. The presence of lead or copper in water is most commonly leaching from the plumbing system or well rather than the groundwater. Acidic water is easily treated using an acid neutralizing filter. Typically, these neutralizing filters use a granular marble, calcium carbonate or lime. If the water is very acidic a mixing tank using soda ash, sodium carbonate or sodium hydroxide can be used. The acid neutralizing filters will increase the hardness of the water because of the addition of calcium carbonate. 17.1% of the wells tested were found to have acidic water and 2.9% were found to have a high pH (probably from too much salt in the water softener) this year. A too high a pH is usually from over treating with a water softener, but can be an expression of salt water infiltration or other pollution.

Water that contains high levels of dissolved minerals is commonly referred to as hard. Groundwater very slowly wears away at the rocks and minerals picking up small amounts of calcium and magnesium ions. Water containing approximately 120 mg/L can begin to have a noticeable impact and is considered hard. Concentrations above 180 mg/L are considered very hard. Hard water can be just a minor annoyance with spotting and the buildup of lime scale, but once water reaches the very hard level 180 mg/L or 10.5 grains per gallon, it can become problematic. Overall, 7.1% of homes tested had very hard water. (It is to be noted about half of homes reported having a water softener.)

Two methods are commercially available (and certified) to treat hard water. A water softener and a water system that work through a process called template assisted crystallization (TAC), have been certified by DVGW-W512 and are available in whole house units. In template assisted crystallization, water flows through a tank of TAC media. When the hard water comes into contact with the media, the magnesium and calcium ions are caught by the nucleation sites. As more calcium and magnesium ions build up within the sites, small micro-crystals form and flow through your plumbing. They do not attach themselves to your water pipes as scale.

The ubiquitous water softening system is an ion exchange system consisting of a mineral tank and a brine tank. The mineral tank holds small beads of resin that have a negative electrical charge. The calcium and magnesium ions (along with small amounts of other minerals) are positively charged and are attracted to the negatively charged beads. This attraction makes the minerals stick to the beads as the hard water passes through the mineral tank. Sodium from salt is used to charge the resin beads. The brine tank is flushed out when the resin beads are recharged carrying the salty solution to the environment. Inland salinization of surface waters and groundwater is an emerging environmental concern. Research has shown that salinization has affected over a third of the drainage area of the contiguous United States even in areas without road salt. At the present time the EPA guidance level for sodium in drinking water is 20 mg/L. Given the number of homes with elevated sodium and our local geology, it is probably a reflection of the number of homes with water softeners-45.7% of the wells tested had elevated sodium.Elevated uranium was found in one sample. Because uranium gets into your body primarily through ingestion (and not through the skin or through inhalation), it is not usually necessary to treat all the water in your home, but only the water you drink. Reverse osmosis (RO) treatment systems are the most common type of treatment used for uranium removal and are very effective.

Traces of other metals were found in a small handful of samples. Activated carbon filters are used to address these problems. When the activated carbon is fully contacted with water, the heavy metal ions will be adsorbed into the developed voids of the activated carbon to remove the contaminant. 

 

My Well Test Results in 2026

While the U.S. Environmental Protection Agency (EPA) regulates public water systems, the responsibility for ensuring the safety and consistent supply of water from a private well belongs to the well owner-in this case me. I test my well water annually. An easy way to do this is to participate in the Virginia Tech Extension Virginia Household Water Quality Program (VHWQP). They are always expanding and improving the program, and looking for emerging areas of concern. Not all of the substances tested for had established health standards.

Under the authority of the Safe Drinking Water Act (SDWA), EPA  established regulatory limits (standards) on over 100 chemical and microbial contaminants in drinking water.   These contaminants include bacteria from human waste, industrial discharge streams (of great concern back in 1974 when the SDWA was first created) and water disinfection by-products and distribution system contaminants. They also regulate naturally occurring contaminants. For each of these contaminants, EPA sets a legal limit, called a maximum contaminant level (MCL). In addition, EPA sets secondary standards for less hazardous substances based on aesthetic characteristics of taste, smell and appearance, which public water systems and states can choose to adopt or not. Then there are the health reference level (HAL) below which health impacts are not anticipated and LHA a level of contamination that if consumed over a lifetime may have health impacts.

What is typically done is to compare the test results to the regulatory or health advisory levels to see if there is an exposure to be concerned about. This is what I saw when I opened my attachment.

None of the chemicals or bacteriological indicators that they tested for were found to be in excess of the U.S. EPA safe drinking water recommended limits. All good. In addition to the 15 contaminants typically found in well water, their instrument that analyzes metals and elements returns data for 14 additional contaminants, many of which are rarely found in well water, that Virginia Tech screens for. None of those contaminants were found to be elevated in my water samples.

In addition, VHWQP also screened for 8 substance for which there is no established health limit so no comparison could be made.

This year and last year, though below the regulatory limit they found trace levels of lead in the first and second draw sample from the powder room sink. While this was all within the EPA safe drinking water limits, I do not believe that there is a safe level of lead. The presence of lead in water that sits for several hours or overnight generally comes the pipes and fixtures and becomes a bigger problem the older the pipes and fixture become. Over time older pipes and fixtures corrode or simply wear away and the lead and other corrosion material (like rust) is carried to the drinking water. Time and water do cause corrosion, but this can be aggravated by the pH of the water or other changes in water chemistry. The amount of lead corroded from metal plumbing generally increases with water corrosiveness.

My water is neutral, I have plastic pipes in the house. It is possible to see traces of lead because there is lead and copper in the well equipment, pressure tank fittings and faucets. Until 2014 when the 2011 Reduction of Lead in Drinking Water Act went into effect, almost all drinking water fixtures were made from brass containing up to 8% lead, even if they were sold as "lead free." Homes built with PVC piping in the 2000's may have some lead in most of the faucets.

Also, before 2014 Prime Western grade “lead free” galvanized steel zinc coating was required to contain between 0.5%-1.4% lead. After 2014, “lead free” galvanized steel must have less than 0.25% lead in the surface coatings. My galvanized steel well casing was installed in 2004. Over time, even under neutral condition, any lead used in coatings can be released to the water and pumped to the household tap or accumulate in scale layers on the pipe surface or well bottom where scale can accumulate and be released or picked up and pumped with the water.

I think in the coming year, I will replace a few faucets. There is little I can do about the galvanized steel casing in the well at this point, though I could research linings. The brass fittings on pressure tanks and pitless adaptors are now available with less then 0.25% lead and were replaced in 2020. A few years ago, at a different sink the results suggested to me that the faucet might be the source- so it got replaced and the following year we did not detect lead. Problem solved there. Now I think it is time to replace the faucet set in the powder room, the sink I used for testing this year and last.

I test my drinking water every year to make sure it is safe to drink. When we bought our home I tested the well for all the primary and secondary contaminants in the Safe Drinking Water Act as well as a suite of metals and pesticides using a certified laboratory. I wanted a comprehensive baseline. Still, I did not test for everything, nobody could afford to (I think there are 80,000 or more known chemicals). At the time I did not test for PFAS it was not part of the Safe Drinking Water Act and the tests available at the time were much less sensitive than is available today, but the test is still very expensive. While you can treat, you cannot really "fix" groundwater. In addition, I wanted a well that was fine without any need for water treatment to address naturally occurring contaminants- my prejudice.


Initially, I tested for Bacteria (Total Coliform and E-Coli), 19 heavy metals and minerals including lead, iron, arsenic and copper (many which are naturally occurring, but can impact health); 6 other inorganic compounds including nitrates and nitrites (can indicate fertilizer residue or animal waste this was once a cattle operation); 5 physical factors including pH, hardness, TDS, alkalinity; 4 Trihalomethanes (THMs) and 47 Volatile Organic Chemicals (VOCs) including Benzene, Methyl Tert-Butyl Ether (MTBE) and Trichloroethene (TCE). Organochlorine pesticides, herbicides and PCBs. Finally, I tasted the water. It tested below the MCL, SMCL and health advisory limits and liked the taste of the water.

I do not have any treatment equipment in the house (except for a kitchen point of use filter), so I was able to do only one set of water tests. When you test a well at a purchase, always test the raw water so that you know what you are buying, and test the water after any treatment to make sure the treatment equipment is working properly. What you can live with in terms of water treatment equipment is really a personal decision. I preferred to have water that did not need of any treatment and was a little hard because I like the taste of hard water. I am picky about my coffee and tea. When the test is more widely available (and cheaper), I will be testing for PFAS. For now, though, its time to replace some faucets and see if the trace of lead disappears. I am concerned because lead was still found (though at a lower concentration after letting the water run for a couple of minutes. My kitchen filter removes lead.

Numerous point-of-use (POU) filters, including pitchers, faucet mounts, and under-sink systems, are specifically certified to remove lead. For verified protection, look for products certified against NSF/ANSI Standard 53 (for health-related contaminants like lead) or NSF/ANSI Standard 58 (for reverse osmosis systems).

2024 U.S. Data Center Energy Usage Report from LBL

Shehabi, A., Smith, S.J., Hubbard, A., Newkirk, A., Lei, N., Siddik, M.A.B., Holecek, B., Koomey, J., Masanet, E., Sartor, D. 2024. 2024 United States Data Center Energy Usage Report. Lawrence Berkeley National Laboratory, Berkeley, California. LBNL-2001637

2024 United States Data Center Energy Usage Report

Our local supervisors here in Prince William County, and our neighboring counties have been approving data centers without any plan. Loudoun County and Prince William, VA, have used "lenient" approvals to build a massive tax base that funds schools, social services, local government, and parks without that could not have been afforded without massive property tax increases. The need for high-capacity transmission lines and additional transmission has forced a reactive and haphazard response to the demands for power and other infrastructure.  We need to look at and plan for what is happening- the creation of a regional data center hub of global proportions.

About a year and a half ago the Lawrence Berkeley National Laboratory (LBL) issued a very important report, for planning infrastructure and the future of our nation. The article below is excerpted from that report cited above.

The Energy Act of 2020 called for an update to Lawrence Berkeley National Laboratory’s prior study entitled United States Data Center Energy Usage Report (2016). This report estimates historical data center electricity consumption back to 2014, relying on previous studies and historical data. This report also provides a forecasted range of future demand out to 2028 based on trends and the most recent available data. The figure below provides an estimate of total U.S. data center electricity use including servers, storage, network equipment, and infrastructure from 2014 through 2028.

U.S. data center annual energy use remained stable between 2014–2016 at about 60 TWh, continuing a minimal growth trend observed since about 2010. In 2017, the overall server installed base started growing and Graphic Processing Unit (GPU)-accelerated servers for artificial intelligence (AI) became a significant enough portion of the data center server stock that total data center electricity use began to increase. By 2018 data centers consumed about 76 TWh, representing 1.9% of total U.S. electricity consumption.

from LBL

 Since 2017 U.S. data center energy use has continued to grow at an accelerating rate, reaching 176 TWh by 2023, representing 4.4% of total U.S. electricity consumption. Lawrence Berkeley National Laboratory went on to forecast total data center energy use after 2023. It is presented as a range of the various scenarios of future equipment shipments and operational practices, as well as variations in cooling technology. There is a tradeoff between water use and energy use for cooling.

Cooling systems, such as shifting to liquid base cooling or moving away from evaporative
cooling determine a significant portion of energy use. Together, the scenario variations provide a range of total data center energy estimates, with the low and high end of roughly 325 and 580 TWh in 2028, as shown above.

Assuming an average capacity utilization rate of 50%, this annual energy use range would
translate to a total power demand for data centers between 74 and 132 GW. This annual
energy use also represents 6.7% to 12.0% of total U.S. electricity consumption forecasted for 2028.

Historically, data center electricity use increased substantially from 2000–2005, roughly
doubling during that period. During the early and mid-2010s, a shift from on-premises data
centers to colocation or cloud facilities helped enable efficiency improvements that allowed data center electricity use to remain nearly constant at a time when the data center industry grew significantly. During this period, improved cooling and power management, increased server utilization rates, increased computational efficiencies, and reduced server idle power allowed growth without increased energy use.

While many of these efficiency strategies continue to provide significant energy efficiency improvements, the expansion of data center services and new types of hardware has ended the era of generally flat data center energy use. The rapid growth in accelerated servers has caused current total data center energy demand to more than double between 2017 and 2023, and continued growth in the use of accelerated servers for AI services could cause further substantial increases by the end of this decade.

The current and possible near-future surge in energy demand highlights the need for future research to understand the early-stage, rapidly changing AI segment of the data center industry and identify new efficiency strategies to minimize the resource impacts of this growing and increasingly significant sector in our economy. The estimates in their report are based on a “bottom-up” energy use that calculates total electricity use from an installed base of data center equipment.

The lack of direct energy data available in a sector with rapidly evolving technologies limits the analysis. The results of the study with all its limitations indicate that the electricity consumption of U.S. data centers is currently growing at an accelerating rate. The compound annual growth rate was approximately 7% from 2014 to 2018, increasing to 18% between 2018 and 2023. Lawrence Berkeley National Laboratory estimates that the growth rate will range from 13% to 27% between 2023 and 2028. Many of those projects are already under construction and the GPUs ordered.

This surge in data center electricity demand needs to be understood in the context of the much larger national electricity demand that is expected to occur over the next few decades as our nation experiences a combination of electric vehicle adoption, onshoring of manufacturing, hydrogen utilization, and the electrification of industry and buildings. We as a nation need to meet data centers’ future energy needs, but also an economy-wide expansion of electricity infrastructure to meet all future needs.

PWC Environmental Sustainability Annual Report

The Prince William County Office of Sustainability has released its first Environmental Sustainability Annual Report, highlighting progress, success stories and ongoing efforts to advance environmental sustainability across the community. 

The report provides a comprehensive look at how the county is implementing the Community Energy and Sustainability Master Plan, or CESMP, and advancing the Environment goal outlined in the 2025–2028 Strategic Plan. It showcases innovative initiatives, measurable outcomes and collaborative efforts taking place across county agencies and the community. 

Let’s step back and review a little background:

In November, 2020 the Prince William Board of County Supervisors (BOCS) adopted the Climate Mitigation and Climate Resiliency goals: reducing greenhouse gas emissions to 50% below 2005 levels by 2030, sourcing 100% of countywide electricity from renewable sources by 2035, achieving 100% renewable energy in county government operations by 2030 and reaching carbon neutrality in county government operations by 2050. 

Then, Prince William County Board of Supervisors authorized the creation of a Sustainability Commission and Sustainability Office.  The first step was to hire a consultant to develop the Community Energy and Sustainability Master Plan (CESMP), which was to provide the road map for how the county will reach its climate goals.

If you read the CESMP (which was adopted in 2023) you will see that there are no realistic scenarios that achieve those goals in the stated time frame. “It was found that due to limited span of control, all five goals will not likely be met through County action alone. It is expected that there would be a gap in emissions reductions needed to hit our 2030 target even if all 25 high priority actions are implemented. It is recommended that the actions are implemented to the best of the County’s ability and to evaluate whether or not to bridge the potential remaining emissions reductions gap using high quality carbon offsets in 2030.” Nonetheless, we need to work towards a more sustainable future, even if we cannot meet the goals in the allotted time frame.

The Office of Sustainability’s mission is to integrate environmental sustainability across county government and the community to help meet the needs of a growing and evolving county. Undeterred by the challenge, their work supports the Board of County Supervisors’ vision of meeting current community needs while protecting quality of life and resources for future generations. 

To date, 17 of the plan’s 25 high-priority actions have been initiated, with 10 currently in active implementation. A great journey begins with a single step. Prince William County has begun moving towards our future. 

“We are excited to share Prince William County’s first Environmental Sustainability Annual Report, which highlights our progress in clean energy, sustainable mobility and long-term planning,” said Giulia Manno, Director of the Office of Sustainability. “This report helps our community stay informed, celebrate achievements and identify opportunities to work together for continued progress.”  

Since 2015, more than 3,100 residential solar systems have been installed across Prince William County. The county has also registered more than 7,600 battery electric and plug-in hybrid vehicles. Since 2021, the county has installed 85 electric vehicle charging stations at county facilities. In addition, rooftop solar systems have been designed for several county buildings. 

The county is also making progress in protecting natural resources and improving environmental resilience. In early 2025, Prince William County completed the restoration of 4,785 feet along Powell’s Creek in the Montclair community, helping reduce flooding and improve water quality. Additionally, a Bandalong trash collection system installed in Neabsco Creek removed 2,185 pounds of debris in 2025, helping prevent trash from entering the Potomac River. 

“This report reflects our commitment to building a more sustainable and resilient Prince William County,” said County Executive Chris Shorter. “The progress highlighted here shows how we are putting our Strategic Plan into action while continuing to invest in the long-term well-being of our community.”

These are all very small steps compared to the challenges faced in achieving the climate and sustainability goals. The challenge was made more difficult by the vast expansion of approved data center operations in the county. Through 2023, the Metropolitan Washington Council of Governments (MWCOG)  updated Greenhouse Gas (GHG) Inventory Summaries show that Prince William County’s community-wide net emissions increased by 22% between 2005 and 2023.

Nonetheless, while total emissions rose by 22%, the county experienced a 42% growth in population since 2005. The per-capita climate footprint is shrinking. While individuals may be getting more efficient, the rapid scale of development is outpacing those gains. Emissions from commercial buildings (mostly data centers) and on-road transportation remain the primary contributors to the greenhouse gas emissions.

MWCOG notes that the county’s forests and trees currently sequester approximately 368,000 metric tons of carbon annually which offsets about 7% of emissions. However, the rapid development that the county has been experiencing has reduced the tree cover. The July 2025 Tree Cover Fact Sheet reported a net loss of 1,952 acres of tree cover on developed or developing lands. This was the result of losing 2,311 acres (largely to impervious surfaces like roads and buildings) while only gaining 360 acres through new growth or planting.

The tree canopy in the Metropolitan Washington region as a whole dropped from 51.3% in 2014 to 49.6% in 2023, local data suggests Prince William has consistently remained below the regional average and the MCOG regional goal of 50% canopy coverage. 

The Environmental Impact of Data Centers

At the last meeting of the Potomac Watershed Roundtable Julie Bolthouse, Director of Land Use, at the Piedmont Environmental Council gave a presentation titled "The Environmental Impact of Data Centers.” The Piedmont Environmental Council (PEC) has extensively documented the environmental impact from data centers, in Virginia, which hosts the world's largest concentration of data centers in the world. I would like to present a few highlights from her talk.

Data Centers are no longer the office parks of the last century that employed lots of people (remember AOL, now long gone). They are now hyperscale behemoths which employ only a handful of people for landscape, security, and a few operators. According to PEC research, the expansion of the data center industry poses significant risks to energy grids, water resources, air quality, and local ecosystems.

This is especially true in Virginia which has three times the mega watts (MW) and square feet of data centers than anywhere else in the nation. Currently, there are about 70 million square feet of data centers now operating in Virginia; however, there are 285 million square feet of data centers that are approved or in the pipeline.

Along with the massive increase in square footage of data centers, is skyrocketing energy demand. In 2025 data centers used 24 Gigawatts (GW) of electricity in Virginia by 2030 data centers are forecast to use 57 GW in Virginia. A gigawatt (GW) is equivalent to the energy generated by a nuclear reactor or gas plant. Dominion Energy of Virginia has received 70 GW of load request and have 48 GW in contracts for power-21 GW of this is in the final stages of contract.

Due to the demand strain, Dominion Energy is providing incremental load. For example, when Dominion Energy receives a request for 300 MW of power, they start the customer with 25 MW and Dominion Energy vamps them up over time.

This all seems wildly out of control and unplanned be each locality only looks at land use. The locality does not look at the power demand or where the power lines will go. More concerning is that the cost of transmission lines and generation is spread amongst all power customers. The old model allocated costs assuming that residential growth is what was driving the growth in power demand, and large customers like data centers receive discounted rates. Of the transmission projects on Dominion Energy’s books:

• $2.4 billion for transmission lines that will provide power only for data centers
• $3.3 billion for transmission lines that will server data centers and other customers
• $1.8 billion for transmission lines that will serve others

Data centers are also impacting the air quality in our region. Data centers rely on massive diesel backup generators for outages. In Loudoun County alone, permits exist for over 4,000 generators with a combined capacity of 11 gigawatts. In all of Virginia there are 10,000 Tier II permitted diesel generators. In Sterling alone, there are 2,000 older Tier II diesel generators. . A PEC-commissioned study found that on-site power emissions could result in up to $99 million annually in health-related damages due to premature mortality and respiratory diseases. This is mostly from PM 2.5 micrograms/m3.

New power plants proposal are also impacting air quality. PJM is modeling that Virginia is going to triple their power generation and that is going to come primarily from gas turbines with data centers installing on-site gas turbines. DEQ recently changed their rules to allow data centers to essentially use their back up generators as peaker plants to avoid tanking down the grid.

Finally, water. Depending on the cooling system, a single data center can consume 3–5 million gallons of water daily, 60%-80% of this water use is consumptive. Julie warns that this usage stresses local watersheds and the Potomac river, especially during drought conditions which we have been experiencing the past few years. In Loudoun, the reclaimed water from the wastewater treatment plant is maxed out at 697 million gallons/day (90% of this is going to data centers). So the Loudoun County data centers draw an additional 952 million gallons of potable water to cool the data centers. While data centers represent only 1-2% of the water drawn from the Potomac River on average, in summer, data centers are 9-12% of the consumptive use of the Potomac River.

The wastewater from data centers contains high levels of salinity and total dissolved solids, corrosion inhibitors, biocides, chlorine, phosphates and other additives. The wastewater treatment plants can’t effectively remove all these contaminants.

The Key Environmental Impacts 

In summary Julie highlights several critical areas where data centers affect the environment:

• Energy Consumption & Grid Strain: This demand from data centers has led Dominion Energy to delay the retirement of coal plants and expand natural gas infrastructure to maintain reliability, threatening state climate and decarbonization goals.
• Water Usage: Depending on the cooling system, a single data center can consume 3–5 million gallons of water daily. This growing water use stresses local watersheds and the Potomac River, especially during drought conditions.
• Air Quality & Public Health: Data centers rely on massive diesel backup generators for outages. These generators increase the small particulate matter in our air.
• The data center buildout converts thousands of acres of agricultural land and forests into impervious surfaces, leading to increased stormwater runoff and pollution in local waterways.
• Local Community Impacts: Proximity to residential areas brings persistent noise pollution from industrial cooling fans and light pollution from 24/7 facility operations.

Prince William County Prefers Concentrated Development

Based on recent approvals and rezonings it is clear that the Prince William Board of Supervisors and Planning Department prefer concentrated development for Prince William County. They rationalize that they can use building techniques to protect the Occoquan Watershed as a substitute for maintaining open wooded areas. This rationalization is based on the belief that concentrated development paired with advanced technological mitigation can manage environmental impacts better than the "status quo" of rural development. I do not believe that they are right.  

The Board and Planning staff have argued that large-scale development allows for "unprecedented levels of environmental protection" that would not occur if the land remained privately owned and developed at lower densities. This is true, but it has served to protect the Occoquan Watershed for all of Northern Virginia.

Supporters, including Supervisor Kenny Boddye, argue that developers can implement specialized stormwater management systems that filter sediment and pollutants more effectively than the natural runoff from a privately owned 5-acre lot. There is no research for this argument either for or against.

Proponents also suggest that low-density rural development is less protected because the county has limited authority to regulate what chemicals (like fertilizers) private homeowners use or to prevent them from clear-cutting their own property. However, there are no restrictions on what chemicals hundreds of individual homeowners can use either. Small lot communities are notorious for their intense fertilization and management of the appearance of the community.

Though high-density approvals often come with proffered conservation easements that legally preserve a portion of the forest in perpetuity, there may be limited benefit to the watershed. The "edge effect" changes the soil moisture and temperature. This kills off sensitive native plants and allows hardy invasives to take over the ground layer. Within a decade, the small area forest has no "recruitment"—meaning no young native trees are growing to replace the old ones and it dies. The proffers contain no allowance for maintaining the forest.  In the Occoquan Watershed, a 50-acre contiguous forest is exponentially more valuable than five 10-acre "preserved" patches surrounded by pavement. The latter will almost certainly succumb to the "choke" within 15 years.

County staff have noted that while wooded areas help with traditional pollutants, "modern" concerns like increasing salinity (from road salt) are regional issues that require infrastructure-based management strategies rather than just land preservation. However, Extensive research, primarily led by the Occoquan Watershed Monitoring Laboratory (OWML) and published in journals like Nature, confirms a direct link between population growth and rising sodium levels in the Occoquan Reservoir. Average sodium concentrations at the dam have nearly tripled since the 1980s, now frequently exceeding health advisory limits. 

Research shows that for every 100 additional people per km², impervious cover in the watershed increases by 3%. This expansion leads to higher road salt application, with salt spikes occurring even as regional snowfall has decreased by 40% over the last century. In addition, approximately 64% of salt ions in the reservoir originate from the population via reclaimed water. You have more people and you have more salt. Also, research by Bhide et al. (2021) found that roughly 32% of the sodium mass in finished drinking water comes from the treatment plant itself due to chemicals (like sodium hydroxide) added to buffer pH and prevent pipe corrosion. 

The Planning Department's approach often involves "condensing development down" to specific areas, which they believe allows for larger contiguous blocks of undisturbed forest to be saved through cluster development provisions. However, the Planning Department has presented the arguments for the same density of housing on a clustered development for increasing the density of housing by 28 times. The Maple Grove plan for 279 houses naturally creates more total asphalt and roof area than 9 houses that could have been developed on that site by right. The "less impact" argument isn't about the total amount of impact, but about the intensity of impact per person. 

Despite these arguments, several major environmental and regulatory bodies have disputed the idea that these techniques can substitute for natural wooded areas. Fairfax Water & the NVRC have warned that runoff from new high-density sites could negatively affect drinking water for the nearly million residents that rely on the Occoquan Reservoir for their water supply.

Environmental groups note that large-scale development like the could lead to of tons of additional sediment flowing into the reservoir watershed annually and the Chesapeake Bay. Civic associations and community groups argue that approving high-density projects like Hoadly Square within the Occoquan Reservoir Protection Area (ORPA) "chips away" at the protection district right after its adoption.

Stormwater BMP’s -What you need to know

Last Friday the Potomac Watershed Roundtable met in Frying Pan Park in Fairfax, VA. One of the speakers was Allie Wagner, a Water Resource Planner at the Northern Virginia Regional Commission (NVRC). Allie was there to introduce us to the “Stormwater Best Management Practice (BMP) Maintenance Guidebook.” Recently updated and released. This guidebook is intended to be a  comprehensive resource developed by the Northern Virginia Regional Commission (NVRC) to help private property owners, homeowners' associations (HOAs), and business operators manage and maintain stormwater systems effectively.

The primary purpose of the guidebook is to reduce stormwater pollution—the leading cause of degraded local waterways—by ensuring that BMPs like rain gardens and detention ponds are properly maintained. According to the NVRC, property owner awareness of maintenance responsibilities varies, with owners of "resale" homes often unaware of their obligations compared to HOAs or businesses. Owners are typically responsible for maintaining specific features like rain gardens (ensuring 72-hour drainage), permeable pavers (sediment removal), and clearing vegetation from dry/wet ponds.

The guidebook attempts to provide practical, non-regulatory guidance and includes an introduction to how these systems function and why maintenance is critical. Guidance on how to identify problems, such as clogged pipes, erosion, or standing water.  Tools for budgeting routine and non-routine maintenance expenses. And contact information for local government agencies across Northern Virginia's member jurisdictions

The guidebook contains 14 Detailed BMP Fact Sheets for the most common BMP’s including:

• Dry Ponds (Extended Detention) and Wet Ponds (Retention).
• Rain Gardens (Bioretention Facilities) and Vegetated Swales.
• Permeable Pavement, Sand Filters, and Infiltration Trenches.
• Green Roofs and Rain Barrels.

an example from NVRC

According to NVRC, unmaintained BMPs can fail, leading to:         

• Increased discharge of nutrients, sediment, and toxins into the Potomac River and Chesapeake Bay.
• Potential flooding or erosion on-site.
• Possible violations of local ordinances or maintenance agreements with local governments.

Above and below are examples of two practices. You can find the guide and complete sheets for these practice at this link.