Drought Continues to Build

The water year runs from October 1 to September 30^th. Thanks to a very wet December and January in the 2023- 2024 water year, last year was only about an inch of rainfall short of the average here in Haymarket despite and extremely dry spring and summer. This year is shaping up differently. Despite the rain this past weekend, where I got under an inch of rain in my gauge, we are still 6 inches of rain behind normal. Not only Haymarket, but the entire Potomac River watershed has had a dry winter.

from CoCoRHaS 5.5 N Haymarket, VA

Virginia generally receives about 44 inches of precipitation per year in Prince William County and over 40 inches in all of the Commonwealth and is historically considered “water rich" area. However, droughts are not uncommon, Virginia has a history of multi-year droughts. The climate forecasts for the region call for longer and more sever droughts and wetter non-drought years. The graph below shows the frequency of drought years since 2000. As you can see, so far the droughts we have seen have been very mild by historical standards. 

 

from NOAA

Below is the groundwater picture at USGS monitoring well 49V in the Northwest corner of Prince William County.  It is clear from the first USGS graph that the groundwater level in well 49V  has falling for 15 or more years. The groundwater is being used up. In the second graph you can see that for decades before that the groundwater level was fairly stable, but the monitoring was not continuous in those days (thus the little circles). The PW BOCS has recently approved the funding to begin groundwater studies and monitoring. 

from USGS

Virginia is dependent on groundwater. According to information from Virginia Tech, the Rural Household Water Quality program and the National Groundwater Association approximately 30% of Virginians are entirely dependent on groundwater for their drinking water. In Prince William County about a fifth of residents get their water directly from groundwater, including the Evergreen/Bull Run distribution system. However, the health of our watersheds and stream flow are dependent on groundwater, too.  Groundwater provides the baseflow to the rivers and streams. While groundwater is ubiquitous in Virginia it is not unlimited. There are already problems with availability, quality and sustainability of groundwater in Virginia in places such as Fauquier County, Loudoun County and the Coastal Plain. 

from ICPRB

After weeks of frigid temperatures, ice is now breaking up in the river and we are able to see the flow on USGS gages. The blue block on the graph below indicates no data due to ice. The flow (blue line) at Point of Rocks is 3,330 cubic feet per second (cfs). The median (gray line) for this time of year is 8,500 cfs. We are currently at less than 40% of median flow.

 

Last week’s U.S. Drought Monitor map for the Potomac River basin shows 75% of the area is in Moderate Drought conditions and 12% is in Sever Drought (mostly the south eastern section of the watershed which includes the eastern portion of Prince William county). This is an increase in Moderate Drought conditions over last week’s map.

 

The DC metropolitan area remains in the Drought Watch declared by the Metropolitan Washington Council of Governments (COG) back in July. Officials are asking everyone to use water wisely during this time. The COG Drought Coordination Technical Committee will convene on March 7 to evaluate the drought declaration.

Forest Conservation Act, Data Centers and the VCA

Tree canopies play a crucial role in supporting environmental and human health. A tree canopy is the upper layer crowns of trees- branches, foliage and leaves. It shades the ground below, providing a continuous cover created by the branches and foliage of multiple trees. Tree canopies provide shade, sheltering wildlife, regulating temperatures (through shade and evapotranspiration), intercepting rainfall, and contributing to air purification by absorbing carbon dioxide and releasing oxygen through photosynthesis. In urban environments, the tree canopy enhances streetscapes aesthetically and improves the overall environmental quality by reducing heat and stormwater flow.

Healthy forests and the urban tree canopy are essential. Urban heat island (UHI) effect is widely recognized as a heat accumulation phenomenon, which is caused by urban construction and tree removal. Healthy, well-managed forests are essential to our economy and provide benefits to people and wildlife in Virginia. Forest loss is also responsible for deterioration of rivers and streams.

Yet, Virginians continue to lose trees at an alarming rate. Virginia’s tree canopy decreased 19% from 2001-2023. The loss of tree canopies diminishes our environment’s capacity to filter water pollutants and reduce air pollution and smog. Trees release fresh oxygen to breathe as the canopy layer provides shade and cools the air, which can reduce pollution levels and lower energy usage in buildings, cutting emissions from power plants. When forests are cut down, they release carbon dioxide and other greenhouse gases that trap heat. The new Forest Conservation Act pinpoints where critical tree canopy loss is occurring to mitigate the effects of extreme heat and pollution.

In 2023 Virginia passed the Forest Conservation Act to address the loss of trees facing Virginia’s tree canopies and forests. The law requires the Department of Forestry to conduct comprehensive assessments of the health of Virginia’s forests and explore the various factors contributing to forest loss, such as increased development, invasive species, road construction, and other infrastructure projects.

The Forest Conservation Act and the Forestland and Urban Tree Canopy Conservation Plan are vital steps towards reducing deforestation, reducing tree canopy loss, and maintaining the health of our landscapes and human communities.  Given the alarming loss of Virginia’s tree canopies, having transparent data on where the loss is happening is essential to guide targeted restoration efforts. Beyond temperature regulation, tree canopies serve as natural buffer zones, preventing polluted water from entering our rivers and streams. Tree roots stabilize soil, reduce erosion, and filter out water contaminants. 

Loosing nearly a fifth of our tree canopy in a small number of years has exacerbated extreme heat waves and the urban heat island effect. In Virginia, the top 11 regions for forest loss were responsible for almost 405 of all tree cover loss between 2001 and 2023. When I looked this up, I expected to see counties with tremendous urbanization pushes, but instead I found predominantly rural counties at the top of the list. Brunswick County had the most tree cover loss at 60.7 kha compared to an average of 9.83 kha. Brunswick was followed by Pittsylvania, Halifax, Buckingham and Sussex. It turns out that all these counties were home to millions of solar panels. We had cut down trees to build solar farms.

In 2020, the General Assembly passed the Virginia Clean Economy Act (VCEA), which mandated a goal of 100% zero-carbon energy generation by 2050 and prescribed increasingly strict Renewable Portfolio Standards (RPS) for Virginia's investor-owned electric utilities.  The energy needs of the Commonwealth, its businesses and its families are changing – and growing at an unprecedented rate.

Virginia is already the data center capital of the world, and the industry is exploding along with the demand for more and more electricity 24 hours a day 7 days a week needed to run them. Data centers require power all the time even when the wind does not blow or the sun does not shine, requiring greater and greater amounts of solar panels, wind turbines and backup power supply and storage.  

Forests and solar energy are both critical to achieving a sustainable climate. However, large-scale deployment of solar farms requires vast land areas, potentially posing conflicts with other land uses. Solar farms have been built in forested regions with a direct reduction in the forest canopy. The clearance of forests and stripping of old growth woods appears to be an obvious source of land for the realization of climate mitigation through solar farm expansion and increased energy needs through data center construction. However, forests also provide climate mitigation as a nature-based solution.

Forests not only absorb approximately a third of the carbon dioxide emitted from burning fossil fuel worldwide each year by sequestering carbon as woody aboveground biomass (Liang et al., 2023), but also provide abundant ecological services such as oxygen release, air purification, soil and water conservation, and biodiversity conservation.

Given the acknowledged importance of forests in shaping policies and decisions related to climate mitigation and achieving carbon neutrality, it becomes evident that building solar farms over forests and knocking down old growth trees for data centers entails substantial environmental expenses including visual impact, land use competition, reduced species richness and increased carbon emission (Ko, 2023; Oudes and Stremke, 2021; Rehbein et al., 2020; Turney and Fthenakis, 2011). 

We need to coordinate our goals and aspirations. Both capping the number of data centers allowed in the Commonwealth and recasting of the VCEA timeline and goals are now necessary.

The Salt Problem

 Snow has come this winter. Last week when I went to the grocery store, the entire asphalt parking lot for the strip mall was white with salt residue. I was grateful as an old woman not to be in danger of slipping, but the salt…The Potomac River and Occoquan Reservoir have become saltier over the decades. This is a problem for the drinking water supply of Northern Virginia and the customers of the local water companies who are eventually going to have to pay to reduce the salt content in the water supplies.

Analyses from three different studies at multiple locations have found increasing freshwater salinization in Northern Virginia and the Occoquan Reservoir. Increasing salt is from increased direct and indirect potable reuse of wastewater, the changing land use,  increased amount of pavement and the salting of roads in the winter. Nearly all road salt is eventually washed into adjacent rivers, streams, and groundwater aquifers - road salt is considered the largest contributor to rising inland salt levels by many. 

The Occoquan reservoir is a drinking water resource for up to one million people in northern Virginia. The reservoir was the nation’s first large-scale experiment in indirect potable water reuse- the practice of deliberately introducing highly treated wastewater to surface water or groundwater for potable supply (Grant et al. 2022). Because of this the Occoquan Reservoir has been carefully and almost continually monitored and studied for decades. They have found that: “approximately 15% (4.6 × 10⁷ m³/yr) of the reservoir’s average annual inflow is highly treated wastewater from the Upper Occoquan Service Authority (UOSA), and the remaining 85% (7.1 × 10⁸ m³/yr) is baseflow and wet weather runoff from two local rivers, Bull Run and the Occoquan River, and ungaged watershed flow (Bhide et al. 2021, Grant et al. 2022).”

The long-term monitoring data reveals that salinity in the reservoir has been increasing over time and is reaching the critical point in terms of taste. “The concentration of sodium ions occasionally exceeds U.S. EPA guidance on taste and health thresholds for drinking water (EPA 2003b, Bhide et al. 2021). Researchers have found that the primary source of sodium ions to the reservoir depends on weather conditions (Bhide et al. 2021); namely, UOSA’s discharges contribute 60–80% of sodium mass during dry weather, and watershed discharges, particularly Bull Run, contribute 40–60% of sodium mass during wet weather. On average, the total daily mass load of sodium to the reservoir is 42,000 kg/day.”

Watershed discharges are assumed to come primarily from road salt.  Road salt is applied to de-ice roads in the winter for highway safety and public safety (like old ladies carrying their groceries to the car). The more paved roads we build, the more salt is used in the winter.

The ICPRB, the Virginia Department of Environmental Quality (VDEQ) and the Northern Virginia Regional Commission joined together to develop a voluntary Salt Management Strategy published in 2020 to reduce that source of salt/ chloride to the Potomac, its tributaries and the Occoquan Watershed. Though it was a first step, this policy alone is not enough to slow the increasing salinization of our source water for drinking as road construction continues at an alarming pace and business use salt and brine solutions to protect their customers and employees. As we try to encourage the adoption of the voluntary salt management strategy, we keep building roads and paving over the open wooded spaces.

Sodium and chloride the elements that make up salt and break apart in water are washed off road by rain and melting snow and flow into local waterways or seep through soils into groundwater systems with negative impacts on water quality and the environment. Salts pollute drinking water sources and are very costly to remove. The only available technology to remove salt from the source water is reverse osmosis which could cost Fairfax Water alone $1-2 billion to install and requires a significant amount of energy to run in the tens of millions of dollars a year.  

There are significant other sources of salt in our watershed, not a single source. The origin of salt is widespread in the watershed which spans four counties, two cities, and three utilities. In addition, the salt content of the UOSA seems also to be increasing. The Occoquan Reservoir watershed cannot be easily regulated because all entities involved must agree and the proposed solution for one entity may adversely affect that of another. "Addressing salinization of the Occoquan Reservoir requires working across many different water sectors, including the local drinking water utility (Fairfax Water), the wastewater reclamation facility (Upper Occoquan Service Authority), the state transportation agency (Virginia Department of Transportation), and city and county departments in six jurisdictions responsible for winter road maintenance, including the City of Manassas, City of Manassas Park, Prince William County, Fairfax County, Loudoun County, Fauquier County.”

In addition, current regulatory tools are not well suited to address freshwater salinization in urban areas. The few federal regulations for salt that do exist address acute and chronic limits for chloride intended to protect aquatic freshwater species, as well as secondary (nonmandatory) guidelines for drinking water. The U.S. Environmental Protection Agency (EPA) unregulated contaminant program determined salt did not present a meaningful opportunity to mitigate health risk and were therefore not regulated. Nonetheless, it is a problem that continues to grow worse as time passes.

The Occoquan Watershed Monitoring Laboratory has obtained several grants to study the potential effectiveness of utilizing Elinor Ostrom’s social-ecological systems (SESs) framework to address the problem (and other distributed contamination problems that are emerging). This framework can be used to assess the social and ecological dimensions that contribute to sustainable resource management.

What the Occoquan Watershed Laboratory researchers did was assemble stake holders from the local drinking water utility (Fairfax Water), the wastewater reclamation facility (Upper Occoquan Service Authority), the state transportation agency (Virginia Department of Transportation), and city and county departments in six jurisdictions responsible for winter road maintenance, including the City of Manassas, City of Manassas Park, Prince William County, Fairfax County, Loudoun County, Fauquier County. The stakeholders were prompted do develop frameworks or mental models for the salt problem using an iterative process that began with co-production of a concept list featuring causes of salinization, consequences of salinization, and actions that might be taken to mitigate salinization. 

The similarities and differences across these groups, and the degree that pointed to actions that could be taken to  collectively manage salinization in the region as well as other challenges to the sustainability of our communities was explored. To increase the likelihood that actions could be taken across a broad swath of stakeholders in the region, widespread understanding of the problem and the interconnection of actions and consequences needed to be communicated.

The Occoquan Watershed Laboratory has moved on to create the first version of a simple to use model to provide stakeholders and decision makers with the actionable information they need to manage cascading water quality risks in more integrated and equitable ways, both now and under various population growth and climate change scenarios. This tool could be used to decision makers to gain an understanding of the consequences of their decisions on the community as a whole. To see the overall impact of individual decisions made over time on the community and ecology.

If the model they are developing could be expanded to represent the impacts of various types of development and climate impacts, we could possibly bring together the waring groups in Prince William County and find an acceptable level and type of development that we all could accept or at least would be sustainable.

from OWML Grant et al 

FDA finally bans Red Dye #3

Red 3, which is also known as erythrosine and FD&C Red No. 3 is being banned in food and drugs. It was removed from use in cosmetics in the 1990’s because there was a study that showed high doses in rats caused cancer. Nonetheless red dye #3 remained approved in food and drug products where it had been used since 1907. Under the Federal Food, Drug, and Cosmetic Act, all color additives and new uses for listed color additives must be approved by the FDA before they may be used in foods, drugs, cosmetics, or certain medical devices, or on the human body. There is no "generally recognized as safe" (GRAS) provision which is how the cosmetic use of Red Dye #3 was banned from cosmetics in the 1990’s.

Manufacturers who use FD&C Red No. 3 in food and ingested drugs now have until January 15, 2027 or January 18, 2028, respectively, to reformulate their products. Other countries still currently allow for certain uses of FD&C Red No. 3 (called erythrosine in other countries). However, foods imported to the U.S. must comply with U.S. requirements.

FD&C Red No. 3 is a synthetic food dye that gives foods and drinks a bright, cherry-red color. The FDA estimates that FD&C Red No. 3 is not as widely used in food and drugs when compared to other certified colors based on information available in third-party food product labeling databases, food manufacturers’ websites and other public information, and the FDA’s certification data. FD&C Red No. 3 has been primarily used in certain food products, such as candy, cakes and cupcakes, cookies, frozen desserts, and frostings and icings, as well as certain ingested drugs. All the petroleum based red dyes are problematic.

Synthetic dyes are prevalent in the global food supply chain. Three dyes Allura Red (Red 40), Tartrazine (Yellow-5), and Sunset Yellow (Yellow-6)] account for 90 % of all dyes used in food in the USA; and Red 40 is by far the most common. Alarmingly, 94 % of people over 2 years old in the USA consume Red 40; and over 40 % of foods marketed toward children in the USA contain such dyes. It is used extensively in processed foods as a coloring for beverages, frozen treats, powder mixes, gelatin products, candies, icings, jellies, spices, dressings, sauces, and baked goods. The increase in the use of Red 40 food coloring over the past several decades, coincides with the rise of early-onset colorectal cancer (EOCRC) that was recently examined in an NIH funded study.  

Their study found data consistent with their hypothesis that Red 40 damages DNA in vitro and in vivo; and that a westernized diet combined with Red 40 causes dysbiosis, functional mutations, and low-grade inflammation in the distal colon and rectum. Their findings indicate that Red 40 in the presence of a high-fat diet for 10 months leads to dysbiosis and low-grade colonic inflammation in mice. These findings supports the authors hypothesis that Red 40 is a dangerous compound that dysregulates key players involved in the development of early-onset colorectal cancer (EOCRC). Read thefull report here.

Really, we all should avoid chemical dyes and additives in our food. I got that advice from my father in the 1960’s when he took me to see how maraschino cherries are made. (My father was a bit of a health and food nut. He was pretty much right.)

Keep Your Pipes from Freezing

This has seen several cold snaps another frigid period is coming this week. It is forecast to be so cold and snowy that they are moving the Presidential inauguration indoors. Virginia has a moderate four-season climate that is typically humid in summers with mild winters, but there is tremendous variation over the Commonwealth and from year to year. There are those dry years, warm years, and cold and snowy years. Because of the usually mild winters here in Virginia, we do not often think of frozen pipes until an artic frost has arrived or when it is too late, and the pipes are already frozen. The forecast for the polar vortex  reminded me to finally turned off the outside spigots and make sure the  hoses were disconnected. 

When sub-zero weather is in the forecast, we need to prepare our homes to prevent our pipes from freezing. Frozen pipes can cost you thousands of dollars to repair. In Virginia, it is common to find bathrooms built above garages, or pipes running through the garage or an attic dormer. If you have a bathroom above a garage keep a small ceramic electric heater ($40) in the garage connected to a thermocouple that turns it on when the temperature in the garage falls below 40 degrees Fahrenheit. Turn on the heating cube in the garage and check it functioning when you turn off the hoses. The best time to do this is around Thanksgiving, but here we are in January.

The likely pipes to freeze are against exterior walls of the home, or are exposed to the cold, like outdoor hose bibs, and water supply pipes in unheated interior areas like basements and crawl spaces, attics, garages, or kitchen cabinets. Pipes that run against exterior walls that have little or no insulation are also subject to freezing. It is easier to prevent pipes from freezing than to unfreeze them.

When the weather is forecast to fall into the teens or single digits (or lower) open kitchen and bathroom cabinet doors to allow warmer air to circulate around plumbing, especially if your sinks are on an exterior wall or against attic dormers, and in the most extreme weather run an extra ceramic electric heater overnight keeping that bathroom toasty while the rest of the house is at an energy saving 63 degrees.

In sub-zero weather wells with and without separate well houses can freeze. Keeping the temperature in a well house above freezing or your well pipe insulated can prevent this. It used to be easy, that inefficient 100-watt incandescent bulb gave off enough heat to do the job, but now with more efficient bulbs, insulation and another source of heat is needed. An electric blanket can do the job. Deep wells are unlikely to freeze, it is usually a supply line not buried deep enough. Abnormally cold snaps can identify a private well line that was not buried deep enough at its most vulnerable point where it connects to the foundation.

Letting the water run in very freezing weather can work; however, can also create other problems. While running water may prevent the water supply lines from freezing, in the coldest weather the slowly running water might cause the drainpipe to the septic system (if you have one) to freeze and block the flow or even burst, and it can overwhelm a septic system. If you are on public water and sewer letting water trickle can prevent frozen pipes. You will see a significant increase in your water usage (still cheaper than repairing the damage from a burst pipe).

Frozen pipes can happen in your supply line or other parts of the house. There are things you can do to prevent frozen pipes. A couple of ceramic electric heat cubes, thermocouple, electric blanket, and a little strategy can prevent frozen pipes if there is heat in the home. However, electric heat pumps are extremely common in Virginia and becoming more so as various climate related programs push to transition to all electric households. This would also be a good time to change the filters on your heat pump to make sure its operating at its best.

If the power should go out during a freeze, there may be no way to prevent the pipes in the home from freezing. Turning off the water at the main may be your best option if the power goes out and you do not have a generator or backup gas heat. Battery backups can help keep essentials running, but not keep your pipes from freezing.

Whatever you do, do not run a gas-powered generator in the house and be wary of propane heaters not meant for interior use. We have a shop propane heater designed for indoor use and comes with an oxygen depletion sensor. These sensors detect the oxygen level in the air and turn off the propane. We also have battery operated carbon monoxide (CO) monitors throughout the house.

CO is an odorless, colorless gas that can kill you. This silent killer shows up any time you burn fuel, and it can quickly take over a home. Symptoms of carbon monoxide poisoning may resemble the flu (vomiting, dizziness, headache). So, use the CO monitors. Keep warm, but be smart.

Cold Snap Caused 220 Broken Water Mains for WSSC

 

On Tuesday WSSC Water lifted the essential water use request for all 1.9 million customers in Montgomery and Prince George’s counties. Over the weekend and through Monday this request to use water only as necessary and conserve where ever possible was in effect. Due in part to the public’s water-conservation efforts, WSSC Water was able to  able to stabilize water pressure, and water storage levels have returned to normal. The Potomac and Patuxent Water Filtration Plants are fully operational to meet customer demand. The problems in the water system were caused by:

• A high number of water main breaks/leaks coupled with water production limitations brought on by the cold temperatures increased the risk of loss of pressure system-wide.
• From January 1-13: WSSC Water has experienced about 220 breaks/leaks in water mains with approximately184 of those occurring in the past 6 days.
• On Sunday, January 12, a 24” water main break and a 12” main break that had not been identified threatened system storage reserves. 

On Monday alone WSSC Water was responding to 52 breaks/leaks. As always customers are urged to contact WSSC Water’s Emergency Services Center at (301) 206-4002 to report any running water or if they smell chlorine, which is used to disinfect drinking water. Reports can also be made via the WSSC Water Mobile App using the Report a Problem feature.

WSSC Water was able to stabilize the system by calling in additional crews and emergency contractors to search for any unreported breaks/leaks and make repairs. With so many breaks happening, WSSC Water was forced to  shut down broken/leaking mains until repair crews were dispatched to the break in an effort to keep the system pressures stable. This caused longer than usual times for repairs and some customers  experienced water outages or lower pressure for more extended periods than usual. 

from WSSC

There is a direct connection between dropping water temperatures in the Potomac River and the increase in water main breaks. When the temperature drops the incidence of water main breaks rise. According to the WSSC, they typically see an increase in breaks a few days after the Potomac River temperature hits a new low. The dropping water temperature can “shock” water mains, and though the pipes become accustomed to the cold water; whenever water temperatures hit a new low, there is a spike in breaks. As seen in the chart above the recent cold snap and the one at the end of November have lead to an increase in breaks.

On average, WSSC crews repair more than 1,800 water main breaks and leaks each year, with the vast majority of them, approximately 1,200, occurring between November and February. WSSC has already repaired approximately 200 breaks and leaks in November and 220 since January 1 this year.  Last winter as seen below, the total number of breaks was above average. There is still a large percentage of the distribution system that is quite old.

WSSC Water spends approximately $17 million each year for emergency water main repairs alone, with about $10 million spent November through February. During a typical year, WSSC Water crews repair more than 1,800 water main breaks and leaks, approximately 65 % of which (1,152) occur between November and February.

Responding to these emergencies has slowed WSSC’s ability to replace the older water mains and WSSC continues to work to update the system. WSSC serves 1.9 million customers in Prince George’s and Montgomery counties, with approximately 5,900 miles of water mains covering a 1,000-square-mile area. With such an extensive, aging distribution system spanning the two counties it is hard to keep up and very difficult to move forward to reduce the age of the system of pipes.

from WSSC

Fairfax County Report on the Environmental 2024

At the end of the year the Environmental Quality Advisory Council (EQAC) of Fairfax County released its annual report. This report is intended to provide a big picture view of how environmental programs are working and identify areas that require attention. For 2024, they found that residents and businesses can expect clean water, and good air quality. They largely attributed the county’s clean water and good air quality to the county’s past environmental investments; however, they felt that the county will need to do more to address climate change and other environmental challenges to maintain a healthy environment and continue to improve our quality of life.

I would like to highlight some of the portions of the report that address water quality and availability and have excerpted them from the report.  The Potomac River and Occoquan Reservoir are the primary source water for Fairfax Water which supplies 85% of the drinking water in the county.  Fairfax Water draws water from the Potomac River near the James J. Corbalis Water Treatment Plant and from the Occoquan Reservoir at the Frederick F. Griffith Water Treatment Plant. The remaining drinking water is drawn from groundwater.

 Fairfax Water provides about 167 million gallons per day (mgd) of drinking water to nearly two million people in Northern Virginia, including most residents of Fairfax County. Fairfax Water also provides drinking water to the Prince William County Service Authority, Loudoun Water, Virginia America Water Company (City of Alexandria and Dale City), Town of Herndon, Town of Vienna, Fort Belvoir and Dulles Airport. As of 2014, both the City of Fairfax and the City of Falls Church systems were incorporated into Fairfax Water’s system. In addition, Fairfax Water purchases some treated water from the U.S. Army Corps of Engineers, Washington Aqueduct Division, treated at plants in Washington, D.C.

Fairfax Water provides highly advanced treatment for the water delivered to its customers, but those treatment systems cannot remove salt, PFAS and other emerging contaminants. Although Fairfax Water produces safe and high-quality drinking water that meets all current standards, some water-quality concerns are appearing at the National level. The U.S. Environmental Protection Agency (EPA) recently released final national primary drinking water standards for six types of poly- and perfluoroalkyl substances (PFAS). According to Fairfax Water’s Statement on EPA’s Final PFAS Standards for Drinking Water, released April 10, 2024, Potomac River water from the Corbalis plant currently meets the standards while the Occoquan Reservoir sourced water from the Griffith plant does not. The standards do not take immediate effect, but Fairfax Water is evaluating treatment processes to ensure that their water will meet these standards. Also, more studies are needed to determine the specific sources of PFAS in the Occoquan watershed.

Fairfax Water does not explicitly identify the Corbalis and Griffith service areas. The boundaries vary depending upon pumping and demand. (Fairfax has interconnections in the distribution system.) Nevertheless, if future concerns arise about either plant’s output, EQAC felt it may be necessary, in the interests of transparency, to provide a map of approximate service areas of water originating in the Occoquan Reservoir and from the Potomac River. There are no plans to differentiate the costs of the water in the service areas.

The Occoquan Reservoir obtains its water from the Occoquan Watershed and the Upper Occoquan Service Authority (UOSA) Wastewater Treatment Plant. The Occoquan Watershed covers about 590 square miles and includes the Occoquan Reservoir, which serves as the boundary between Fairfax and Prince William counties. Unlike the vastly larger Potomac Watershed, the Occoquan water supply is very susceptible to pollutants introduced in local jurisdictions and through the recycled water from UOSA.

According to a recent Wall Street Journal Report, roughly 250 existing data centers in Northern Virginia use about 4,000 MW of electric power, and another 7,000 MW could be added with the data centers approved and under construction. EQAC differentiates the water and power use of the older data centers from the newer projects just completed or under construction. Older data centers typically range from 10 MW to 50 MW in size and use conventional commercial air conditioners for heat dissipation. Newer data centers are larger, around 300 MW; requiring this much more cooling capacity to dissipate the heat from the energy use makes evaporative cooling, commonly used for power plants, an attractive option.

A 300 MW data center would need to evaporate about 3 million gallons per day (mgd)  of water to the atmosphere. Adding 7,000 MW of data center capacity using evaporative cooling would introduce about 70 mgd of consumptive water use, almost doubling existing consumptive water uses in the Potomac River Basin. None of this increased usage is included in the 2020 ICPRB estimates. All evaporative cooling systems concentrate any solids and other contaminants in the water and must discharge highly saline “blowdown” water. This is particularly worrisome in the Occoquan basin, where sodium levels already are of some concern. At present, it is not known if new data centers will actually request water for evaporative cooling, nor is it known if mitigation, such as interruptible water service, would be acceptable.

 Though the recycled water from UOSA is already part of the water supply for the Griffith plant, recycled water from the Noman M. Cole Jr., Wastewater Treatment Plant which currently treats about 40 mgd  may be an option for reuse for evaporative cooling. Clearly, any use of evaporative cooling for new data centers must be considered carefully as a regional issue and the type of cooling should be stated at approval. Considering their potential impacts to water supplies, EQAC recommends, if large data centers are approved with evaporative cooling, conditions must consider (1) Possible water cutoff during periods of drought; (2) Use of recycled wastewater where feasible; and (3) No return of any “blowdown” to the Occoquan Reservoir.

EQAC made three recommendations one from the 2023 report.

1. Continue and enhance the protection of the Occoquan Reservoir by developing a plan for managing threats such as PFAS and sodium. Fund monitoring and modeling of emerging contaminants such as PFAS and of the rising sodium levels in the Occoquan Reservoir. This effort should include an inventory of present and proposed pollution sources, such as data centers and other industrial facilities.
2. Continue to participate with the ICPRB in studying water supplies in the Potomac River. In particular, ecological studies of low flows in the Potomac Gorge.
3. If large data centers are approved with evaporative cooling, approval conditions must consider (1) Possible water cutoff during periods of drought; (2) Use of recycled wastewater where feasible; and (3) No return of any “blowdown” to the Occoquan Reservoir.

 

Organofluorines in Wastewater

B.J. Ruyle, E.H. Pennoyer, S. Vojta, J. Becanova, M. Islam, T.F. Webster, W. Heiger-Bernays, R. Lohmann, P. Westerhoff, C.E. Schaefer, E.M. Sunderland, High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans, Proc. Natl. Acad. Sci. U.S.A.122 (3) e2417156122, https://doi.org/10.1073/pnas.2417156122 (2025)

The article below is to a large extent excerpted from the above cited article.

Since the 1940s, humans have synthesized tens of thousands of organofluorine chemicals that are extensively used in products such as refrigeration, fluoropolymers, pharmaceuticals, agrochemicals, and nonstick and greaseproof coatings. A subset of organofluorine compounds, per- and polyfluoroalkyl substances (PFAS), has garnered intense interest in recent years because they have been associated with numerous adverse effects on the health of humans and wildlife; and recently been regulated by the U.S. Environmental Protection Agency (EPA). In 2024, the US Environmental Protection Agency (EPA) finalized federal regulations for six PFAS in drinking water: PFOS and PFOA and the hazardous mixture of PFBS, perfluorohexane sulfonate (PFHxS), perfluorononanoate (PFNA), and hexafluoropropylene oxide dimer acid (HFPO-DA/GenX)

Municipal wastewater is increasingly being used to supplement drinking water supplies. With an environmental buffer, such as a lake, river, or a groundwater aquifer, before the water is drawn to and treated at a drinking water treatment plant is called indirect reuse. There is also direct potable reuse where the wastewater stream is simply treated further and sent to the drinking water distribution system. The contaminants in the wastewater are a growing concern that is being highlighted by the appearance of PFAS in the EPA mandated testing of drinking water supplies.  Some municipal water supplies may be receiving PFAS contaminants from the wastewater used to supplement water supplies.

Municipal wastewater treatment facilities receive PFAS from diverse domestic and industrial sources and have been thought to be associated with impaired drinking water quality across the United States. To better understand the magnitude and composition of aqueous organofluorine discharged from large wastewater treatment facilities, sampling was necessary and the above cited study does just that. 

The complexity of analytical methods used to detect and quantify organofluorine in wastewater has in the past limited our understanding of its prevalence. Most wastewater measurements have focused on a few intensively studied PFAS. However, recent work using bulk organofluorine measurements such as extractable organofluorine found the presence of large quantities of unknown organofluorine.

Prior work on wastewater biosolids suggests that pharmaceuticals may account for a substantial fraction of the unknown extractable organofluorine mass. The researchers constructed a mass budget for extractable organofluorine  measured in the wastewater influent and effluent samples from eight large wastewater treatment plants. These plants were chosen because they use similar treatment technologies and are similar in sizes as those serving 70% of the US population. Measurements of extractable organofluorine  taken  in this study were combined with the DRINCS model to quantify wastewater impacts on downstream drinking water sources. Results of this work provide estimates of the number of drinking water facilities (and their service populations) which would need to mitigate upstream wastewater-derived organofluorine sources and/or implement advanced drinking water treatment to prevent exposures to toxic substances.

The sum of targeted PFAS, precursors, and fluorinated pharmaceuticals explains all of the EOF in aqueous influent and effluent samples in this study, within commonly accepted uncertainty bounds (±30%) in all but two samples. What they found was that extractable organofluorine  was poorly removed during wastewater treatment.  

All eight wastewater treatment plants in this study had primary (physical screening/settling) and secondary (microbial processing of labile organic matter) treatment. Half of the facilities had advanced tertiary treatments including ozonation, activated carbon filtration, and ultrafiltration. However, they found a maximum of 24% decline in aqueous-phase extractable organofluorine  compared to influent and no significant differences between aqueous influent and effluent concentrations 

The six EPA regulated PFAS accounted for an average of 8 ± 8% of the extractable organofluorine  in the wastewater treatment plant effluent samples. PFOS and PFOA exceeded federal standards in 63% of the effluents, while the hazardous PFAS mixture standard was not exceeded in any effluent. The greatest exceedance at any facility was observed for PFOA (six times greater than the regulation). At that site, environmental dilution with contaminant-free water or drinking water treatment up to a factor of six would be needed to prevent downstream concentrations that exceed regulatory standards. This could be very problematic for wastewater treatment streams like UOSA which can during dry periods be a significant portion of the flow into the Occoquan Reservoir. Testing has found that public drinking water not only from the Occoquan Reservoir, but also in Newport News, Norfolk, Roanoke and Charlottesville exceed the EPA regulatory limits. This impacts 29% of Virginians. 

Chemical regulation in the United States typically considers risks associated with individual chemicals rather than the complex mixtures present in wastewater effluent or the environment. But the world has changed as more and more of the water we drink is either directly or indirectly recycled. This poses a challenge for regulating PFAS, pharmaceuticals, and other organofluorine compounds because there are potentially tens of thousands of these chemicals currently in use. Most organofluorine compounds lack analytical standards needed for routine environmental measurements and for evaluating toxicity. It may be time to reconsider the water treatment requirements for water reuse both direct and indirect.

Somethings Got to Give

Just after Christmas the Energy Information Administration (EIA) release an analysis that showed that: “In 2023, Virginia emerged as the top net electricity recipient among all U.S. states. … While 25 states produce more electricity than they consume, the excess is transmitted to other states. Virginia’s utilities received a net 50.1 million megawatt-hours (MWh) of electricity from other states, making up 36% of its total electricity supply.”

For comparison California has 0ver 39 million residents and Virginia has 8.7 million residents. California generates net 19,279 thousand MWh of electricity while Virginia generates net 9,078 thousand MWh.

 

For decades, utilities in California and Virginia have consumed more electricity than they produce. In 2023, power companies in California lost their long-held position to those in Virginia as receiving the most electricity from other states. Electricity generation has increased in both states, but interstate receipts have generally increased in Virginia over the past five years while they have decreased in California. Between 2019 and 2023, electricity receipts by Virginia utilities increased by 61% (19.0 million MWh) due primarily to the surging commercial-sector demand from data centers. 

Pennsylvania led the nation in exporting electricity, moving 83.4 million MWh across state borders, accounting for 26% of its total generation.” Pennsylvania and West Virginia have essentially been supplying the explosive growth in data center growth in the PJM region.

 As you can see in the charts below from the appendix of the Dominion Energy fall 2024 update to their Integrated Resource Plan ( IRP) , carbon intensity had been falling in for Virginia. The projected carbon intensity was not included in the diagram. However,  sooner or later, you run out of other people’s power to purchase and there is a projected sudden change in the generation mix for 2024. Buried in the Dominion Energy IRP released last fall is the fact that the carbon intensity of the Virginia electric grid was projected to have increased 37% from 2023 to 2024. Though Dominion’s IRP attributes the increase in carbon intensity to the increase in use of natural gas, that is not completely true. The generation mix changed from 2023 to 2024 to halve the purchased power and make up the difference using natural gas and coal generation.

PFAS and Fairfax Water Update

Fairfax Water gave an update on their work to ameliorate their PFAS problem in the Occoquan Reservoir to comply with the U.S. Environmental Protection Agency (EPAs) new national drinking water standard PFAS chemicals. 

In April 2024, the EPA announced the final national primary drinking water standards for six poly- and perfluoroalkyl substances (PFAS). Public water systems have five years (by 2029) to implement solutions that reduce these PFAS if monitoring shows that drinking water levels exceed the maximum contaminant levels (MCLs). Fairfax Water has stated that they will ensure their water meets these standards by the regulatory date.

image from Fairfax Water

Fairfax Water  supplies not only Fairfax, but parts of Loudoun and Prince William County as a water wholesaler to American Water and Prince William Service Authority . Fairfax Water participated in the Virginia Department of Health (VDH) Occurrence Study that was completed in 2021. It is important to point out that the practical quantitative limit was 4 ppt just at the proposed regulatory limit. Some of Fairfax Water’s results for PFOS and PFAS were above the MRL and the regulatory limit. The ones below cannot be quantified, they might be just below the quantitative limit or lower.

Prince William Water (then called the Prince William County Service Authority) also participated in a Virginia Department of Health (VDH) study to test for PFAS in water samples collected from the distribution systems. The Service Authority collected samples from its East and West systems and the results for the east system (which comes from the Occoquan Reservoir) were above the detection limit and ultimately the EPA MCL.

At the time that EPA finalized the primary drinking water standard, Fairfax Water said: “Our data shows that the PFNA, HFPO-DA (commonly known as GenX chemicals), PFHxS, and PFBS levels in our water are all below the MCLs and HI. PFOA and PFOS results for Potomac treated water are less than the MCL of4.0 parts per trillion (ppt). PFOA and PFOS results for the Griffith Water Treatment Plant, which treats water from the Occoquan Reservoir, are slightly above the MCL of 4.0 ppt. Fairfax Water is evaluating treatment processes to ensure that our water will meet these standards.”

Fairfax Water performed additional sampling and testing. Fairfax Water hired an independent lab to test their water Every sampling found elevated PFOA and PFOS at or near the MCL of 4.0 ppt. 

image from Fairfax Water

Now, Fairfax Water has made available the 2024 third quarter update of their work on PFAS and their conclusions. Based on the most recent quarterly running annual average (RAA), the Occoquan (Griffith Water Treatment Plant) will not comply with the EPA regulation for PFOA when it goes into effect in 2029. Compliance for PFOS is marginally below the regulatory limit. Additional treatment processes will be required to comply with regulations.

Sampling data for the Potomac River water supply indicate that the Corbalis Water Treatment Plant will comply with the PFAS regulations without additional treatment. So, Fairfax Water is moving ahead with designing a water treatment train to remove PFAS from the water drawn from the Occoquan Reservoir.

Fairfax Water estimates that it will cost $389 Million over next 6 years to comply with the EPA MCL by 2029.  This begins with studies of removal technology and bench testing which took place this past year. Next year they plan to have a pilot plant up and operational. Finally, the Design and Construction of plant scale PFAS Removal and Treatment should be completed by the end of 2029. Additional PFAS infrastructure may be required to support the new Luck quarry reservoir supply. In addition to the capital expenditures Fairfax Water expects to spend around $24 million per year in additional operating expenses forever. This is about one fifth of their current operating expenses.

The water in the Occoquan Reservoir comes from the Occoquan Watershed. Our water supplies are connected to each other and the land. Two thirds of the Occoquan Watershed that supplies the Occoquan Reservoir is in Prince William County. The former Rural Crescent allowed rainwater to flow gently over vegetation, feed the aquifers that provide water to the private wells and the Evergreen water system, but also feeds the tributaries to Bull Run and the Occoquan River assuring the base flow to the rivers and streams that feed the Reservoir.

The Upper Occoquan Service Authority, UOSA, the wastewater treatment plant also delivers 40 million/day of recycled water that originated in the Potomac River to the Occoquan Reservoir. Supplementing the supply. Keeping PFAS out of the source water is a real challenge when PFAS is in our diet and wastewater is reused in our drinking water supplies. To stay within the regulatory limit, Fairfax Water will have to identify the PFAS content in the various sources of water and can either mix them to minimize exposure or remove them.

Armed with $750,000 in new equipment for the purpose, the Occoquan Watershed Laboratory has been testing water samples from throughout the Occoquan watershed to determine where the PFAS in the reservoir is coming from to see if it is possible to address the problems at the sources at the expense of the polluters rather than the water customers. PFOA and PFOS were found above drinking water MCLs in multiple sampling locations at levels several times higher than the drinking water limit.

Image from Fairfax Water

Sampling has so far confirmed Industrial wastewater discharges to UOSA from Micron Semiconductor plant and from Freestate Farms. Also confirmed as a source of PFAS by sampling is the  Federal/Military in the Vint Hill area and  Vint Hill Farms. The old Vint Hill army base where the Fauquier Times reported that for the past several years, the U.S. Department of Defense has been monitoring PFAS contamination at Vint Hill that is believed to be tied to a former burn pit where soldiers practiced putting out fires with firefighting foam containing PFAS chemicals, which then leached into the soil and the groundwater. These sources have been confirmed by sampling.

There are also several potential sources that need to be further investigated: the non-Micron reclaimed water from UOSA, accidental releases from Manassas airport, Dulles Airport, the legacy CERCLA sites – IBM in Manassas and  Atlantic Research in Gainesville currently being redeveloped into data centers. PFAS in biosolids land applied under a permit in the watershed.

Occoquan stakeholders are engaged on the PFAS issue - UOSA, Fairfax County, Prince William County, Prince William Water, Virginia Tech (Occoquan Watershed Monitoring Lab), Virginia Department of Environmental Quality (DEQ), Virginia Department of Health (VDH)

Ongoing and emerging efforts to characterize PFAS include:

• Adding PFAS to existing groundwater monitoring sites
• Adding PFAS to the scope of the Occoquan Watershed Monitoring Program
• Working with potential sources to understand past and/or ongoing use of PFAS
• Characterizing PFAS in industrial wastewater discharges to UOSA
• Monitoring other wastewater and industrial stormwater discharges for PFAS