One Goal

 The Wall Street Journal reported that Amazon announced 14,000 workers would be laid off on Tuesday. This is just a first move in layoffs that are expected to affect as many as 30,000 corporate jobs. An “Observant Economist” noted:

“Apparently the most important thing in the whole world right now is creating as many data centers as possible with the primary goal of AI for throwing average people out of work. It is more important than housing or the deficit, more important than climate change, endangered water supplies or a hijacked and plundered electric grid, more important than quality of life or stopping genocide. Only data centers can create our future and nothing else counts.”

Northern Virginia is the largest data center market in the world, constituting 13% of all reported data center operational capacity globally and 25% of capacity in the Americas. The data center industry is growing rapidly in both in established markets and newer ones.

Just to give you a snapshot of Prince William County data center growth, currently there are 33 data centers in operation in Prince William County with an estimated square footage of around 10,000,000 square feet of space.  Currently under construction or development is an additional 59,000,000 square feet of data centers. This excludes the digital gateway project whose rezoning was voided, but is under appeal.

The Joint Legislative Audit and Review Commission (JLARC) issued their report on the impacts of the data center industry in Virginia. Below are excerpts from the Commission’s report .

JLARC found that a substantial amount of new power generation and transmission infrastructure will be needed in Virginia to meet this energy demand or even half of this unconstrained demand. Building enough infrastructure to meet energy demand will be very difficult to achieve and cannot be accomplished while meeting the Virginia Clean Economy Act (VCEA) requirements. We either must slow or limit the construction of data centers in Virginia or repeal the VCEA. You can’t do both.

Water is our most important or critical resource (no water, no people) and how we manage its use or allow its abuse may determine the fate of our region. On earth all the water that ever was or will be is here right now and has been here for over 4 billion years. There is no mechanism on earth for making or destroying water. Mankind has interrupted the flow of streams and rivers by diverting water for irrigation, withdrawing drinking water,  industrial water and building reservoirs. We have also interrupted the recharge of groundwater by changing land use, covering former open land and woodlands  with buildings, driveways, roads, walkways and other impervious surfaces which reduce groundwater recharge in the surrounding area. 

The Metropolitan Washington Council of Governments projects that the population in our region will reach nearly 6.8 million people by 2050 an increase of 1.1 million people, while our available water resources will not increase. Though only recently noticed by our communities, data centers use lots of water. Not at the magnitude of power use, but nonetheless they are estimated to use about 0.5 gallons of water for each kilowatt-hour consumed- millions of gallons a day and growing. Unfortunately, power usage and water usage at specific sites are guarded as trade secrets so we cannot adequately plan for the power nor the water demand as the region’s data centers continue to be built out. The approval process has given a blank check to put unlimited demand on limited resources.

Once the temperature nears 95 degrees Fahrenheit (summer), water cooling is uniformly used in data centers. In a water-cooled system, water-cooled chillers and cooling towers located on top of the data center roofs produce chilled water, which is delivered to computer room air conditioners for cooling the entire building. These systems include the cooling towers, chillers, pumps, piping, heat exchangers / condensers, and air conditioner units in the computer rooms. Additionally, data centers need water for their humidification systems (to avoid static discharges) and facility maintenance.

 Changing climate and population growth are only exacerbating an already existing problem. Our region is already experiencing water stress in the summers. 

The House has a Well-what you should know

Virginia is a "buyer beware" state. Any well or groundwater problems not detected by the buyer during the sale process become the buyer's problem upon closing the sale. There is no legal recourse back to the seller. If you are buying a home you need to make sure that the well is constructed properly and that the groundwater that is drawn into the home is safe to drink, and there is adequate water to supply the home for the foreseeable future. A mistake could impact your health, the value of your home or require you to spend thousands of dollars to solve the problem.

If you are contemplating buying a home with a well, you need to make sure that the well is constructed properly and that the groundwater that is drawn into the home is safe to drink. Though there are many treatment options to fix contaminated water, you might not want to buy problematic water and some water problems can create a cascade of issues, so I have eliminated them. If you are buying a house, you need to make sure that you will have an adequate and safe water supply. This is not the same thing as strategies to live with diminished well yield or fixing your existing water quality problems. Those strategies are how you survive a mistake or a failing well or groundwater system. This is your one chance to make sure the water supply to the home is acceptable before you buy the home, there is no recourse after you buy the home.

The list below is a quick and dirty guide to try and keep you out of trouble. Do not call me a give me story about how the well at the house you love should be okay and ask me to agree with you. These are the most basic items to ensure a safe and lasting water supply, and you will love that house a whole lot less if does not have adequate water to do laundry and take a shower in the summer.

1. The house must have 2-3 acres of land.
2. There must be a well completion report on file with the county health department that shows:
1. The well stabilized yield should be greater than or equal to 6 gallons/minute
2. The well should be drilled and more than 100 feet below grade (deep)
3. The well should be a 6 inch diameter pipe with a bolted cap sticking at least a foot out of the ground. The well cap should be a sanitary sealed cap.
4. Do not buy a home with a shared well
5. The well was drilled after April 1, 1992 (under the current regulations).
6. The well head must be at least 100 feet from the nearest edge of the septic drainfield and at least 50 feet from the nearest corner of the house.
7. Health Department records show regular septic pump outs at least every 5 years. Annual inspections for alternative septic systems should be on file.
8. Don’t buy a house with a well in Karst terrain. The geology is likely to undermine the well eventually.
9. Test the well water for all the primary and secondary contaminants regulated under the safe drinking water act as well as pesticides. At the very least test the well water for Total coliform, E. coli, nitrate, lead, iron, pH, hardness, and residual chlorine. Test the water before any water treatment in the house.
1. Don’t buy a house with a well that found E. Coli is present in the water or nitrate at more than three times background levels (of 2mg/L).
2. Don’t buy a house that found lead present in a flushed sample.
3. The well water must have a pH > 6.0
10. Draw a glass of water from the cold tap in a bathroom sink and taste it. Don't buy a house with water you don't like. 
11. Check the dates on the labels for any well equipment in the basement.

Virginia Tech Extension recommends that buyers should engage a licensed well contractor to assess the well and any treatment. As part of the assessment, the home buyer should obtain a copy and review with the licensed well professional the "Water Well Completion Report" and the septic system (or AOSS) repair/permit history and the history of septic tank pump-outs. This information is on file at the local health department. Usually, they will just email it to you if you ask.

If you see more equipment than a blue pressure tank in the basement you need to know what water treatment equipment is being used, why it was installed, and if it is working properly. It is not always obvious what a particular piece of equipment is just by looking at it because manufacturers tend to use the same casing style for all their products. You will need to test the water before the treatment equipment and after the equipment and determine if you can or want to live with the findings. There is a limit to the life cycle of any equipment and wells themselves. How old the equipment is can determine how effective it is and how long it will continue working. Filters need to be replaced regularly (and that is not free).

For purchase I would recommend a broad stroke water test that looks at all the primary and secondary contaminants regulated under the safe drinking water act as well as pesticides. These kinds of tests exist. An example is the WaterCheck Deluxe plus pesticides test kit from National Testing Laboratories which is an EPA certified laboratory. There are others, but that is the one I always use. Buying a package reduces the cost though the drawback is these packages are performed at a lower sensitivity level. All the packages compare their results to the  US EPA’s Safe Drinking Water Act limits for the primary and secondary contaminants. Since there are no regulation for private well water, that is a reasonable standard to compare the water test results to. Be alert to anything that should not be in groundwater. The presence of low levels of manmade contaminants may be an indication of a bigger problem. If you find traces of hydrocarbons or solvents do not take it on, walk away.

There are no national standards for construction of private water wells, thought in recent decades more and more states have developed standards at least for construction. Wells are typically managed and regulated by the State or Local Health Districts, state departments of the environment or ecology. You need to know what the regulations are in your local area and when they were implemented. In Virginia the regulations went into effect in 1992. You want a well that was built to the current standards, and many wells do not last more than 30-40 years. Geology matters in how a well ages. Check water level and yield in an old well. Yield tends to diminish over time in drilled bedrock and fractured rock wells. Groundwater aquifers are also being widely overdrawn and recharge is being diminished by land use change. It is entirely possible that the aquifer feeding the well is failing. This has occurred in Waterford, Virginia and areas of King George’s county to name just two.

Most states require a permit to drill a well and well drillers to be licensed. Make sure you know what that means in your location. In Virginia that is a decent standard, but in Pennsylvania anyone with $60 can get a well driller license, there are no minimum training or knowledge required there. There are still a few locations where a shallow dug well does not require a permit or license. Know these things when you go looking for a house with a well. Never buy a house with a dug well they are too shallow and are too easily contaminated in our modern world.

In Virginia the well completion report tells you how old the well is, how deep the well was drilled, where water was found and what the well yield was at completion. The well should have a stabilized yield greater than 6 gallons a minute to serve a modern home over time, because well yield typically falls over time. If you are buying a bedrock well older than 20 years, but still built after 1992 hire a well driller to check the water level and yield. Make sure they test the well yield not the pump rate. (Filling a bucket using your pump without accounting for the drawdown of the static column of water only measures the pump rate. The well driller’s rule of thumb is to run the water 4 hours testing flow every 15 minutes using an appropriate sized pump.) It is worth the time and expense to know that the well is still producing enough water.

There are a number of things that should be true in construction of all wells. The well cap should fit tightly on the top of the well casing, be vented, and have a screen to prevent insects from getting in the well. A sanitary well cap is the best option for protecting your well. The well cap should be at least 12 inches above grade, or higher if in an area that is prone to flooding, to ensure that the well cap is never covered by flood water. The area between the casing and the borehole, called the annulus, should be grouted (filled with bentonite and/or concrete) that will not allow any surface water around the well to go down the well bore or along the casing carrying surface contamination into the groundwater. 

Fairfax Water Proposes their annual Rate Increase

Water bills in our region continue to increase. There is no true “cost” of water, the price charged for water, often does not reflect its value or true cost.  Not only inflation is the cause. Recent demand changes, trace amounts of PFAS and rising levels of salt in the source water, and the need to expand and maintain the physical infrastructure of the water treatment and distribution systems and pushed up the costs.

Fairfax Water announced its intention to raise their water rates next spring as they do almost every winter. There will be, as usual, a public hearing on Thursday, December 11, 2025, on the proposed rate increase held at Fairfax Water’s main office at 8570 Executive Park Avenue in Fairfax. This rate increase is part of their ongoing program to ensure that the water infrastructure in Fairfax County is maintained. The proposed rate increase will go into effect April 1, 2026. Visit Fairfaxwater.org/rates for a complete list of rate and fee increases, but the bottom line is that the average customer bill will increase by about 7.5%.

The need for infrastructure replacement is an issue that has caused significant service problems and rate increases in other parts of the Washington Metropolitan region. Fairfax Water Board of Directors have dedicated funding to infrastructure maintenance and replacement for many years and has forecast future capital needs for replacing water mains in the system. The Town of Leesburg did not have a capital program in place. 

This time around Fairfax Water is facing the need to build the treatment to address the PFAS levels in the Reservoir as well as the increasing inland salinization.  In April 2024, the EPA announced the final national primary drinking water standards for six poly- and perfluoroalkyl substances (PFAS). Public water systems have until 2031 (as revised by the current administration) to implement solutions that reduce these PFAS. Sampling has found that the Occoquan Reservoir exceeds the  maximum contaminant levels (MCLs) for PFOA. Compliance for PFOS is only marginally below the MCL. Additional treatment processes will be required to comply with regulations and Fairfax Water has stated that they will ensure their water meets these standards by the regulatory date.

Fairfax Water hopes to use a new law, the Occoquan Reservoir PFAS Reduction Program, signed by the Governor this past summer  to identify and remove enough of the sources of PFAS in the water that arrives at the Occoquan Reservoir to meet the EPA MCL without requiring Fairfax Water and their rate payers to foot the bill for compliance which at this point is estimated to be about $400,000,000 in capital investment and $24,000,000 per year in operating costs. None of the treatment cost are in the current rate increase, but the expenses of the proactive planning process are. 

In January of this year, Fairfax Water filed a lawsuit in the Circuit Court of Fairfax County against several manufacturers of aqueous film-forming foam chemicals. The lawsuit seeks to hold companies responsible for PFAS contamination in the Occoquan Reservoir and recover costs associated with water treatment and environmental remediation. (There have been several spills of aqueous film-forming foam chemicals at Manassas airport alone.) 

Every time they propose to raise water rates, Fairfax Water performs a comparison of the water costs throughout the Washington Metropolitan region. I have tracked this information over the years, and was shocked to see rates decrease this year, until I read the footnote. The comparison of rates as of July 2017, 2018, 2019, 2022, and 2023 was based on a quarterly use of 18,000 gallons of residential water. In 2024 Fairfax Water choose to change the quantity of water used for the comparison to 15,000. This not only appeared to reduce rates in 2024,  but also changed some other aspects of the pricing. Last year I adjusted up the rates by 120% to make them more or less comparable to previous years, but this year I did not. Fairfax Water’s rate has returned to the lowest in the Washington metropolitan region, but they choose the comparison rules.  Fairfax Water sells water to Prince William Service Authority, American Water, Manassas Park and others.

from Fairfax Water data

Solar Demonstration Farm

Roundabout Meadows is the 140-acres of land that is bisected by Howser’s Branch Drive. The triangle of land that became stranded by the installation of the Route 50 traffic circles and the building of Howser’s Branch Drive contains the Community Farm at Roundabout Meadows; the address is 39990 Howsers Branch Dr. Aldie, VA 20105.

The Piedmont Environmental Council (PEC) was given the140-acres at the southeast quadrant of US Route 50 and US Route 15 known around here as Gilberts Corner by a citizen group led by Scott Kasprowicz, a former member of the PEC Board of Directors. The group, Roundabout Partners, raised the funds and purchased the property to prevent a planned development. After purchasing the land they then donated the 140 acres to the Piedmont Environmental Council (PEC) for conservation purposes more than a decade ago. 

Now, the farm is being used for an agrivoltaics demonstration project. The PEC is experimenting with growing crops under solar panels to determine what works and what doesn’t. A small corner of the farm has become a crop-based agrivoltaics demonstration project. They hope the combination of solar panels and vegetable farming will showcase how much-needed renewable energy can complement, not harm, agricultural lands, at a time when data centers are demanding more and more electricity.

from PEC

In 2020, the General Assembly passed the Virginia Clean Economy Act (VCEA), which mandated a goal of 100% zero-carbon energy generation by 2045 and  2050 and prescribed develop 16,100 megawatts of land-based renewable energy by 2035 — mostly in the form of solar.  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. 

According to the PEC Virginia has more than enough land to meet that target without threatening great swaths of farmland; however, it does threaten trees. Using a conservative metric that 10 acres of land can host 1 megawatt of solar capacity, a Nature Conservancy analysis found that the Commonwealth has 40 times more available land area than needed for solar fields, even after ruling out over 2 million acres of ​“prime conservation lands” including farmland.

Researchers from Virginia Commonwealth University determined that large-scale solar today is erected on less than 1% of the state’s cropland. Under a ​“high-growth scenario,” that figure could rise to 3.1% by 2035, including 1.2% of the state’s federally designated prime farmland. Yet low-density residential development may pose a far greater threat to those spaces, according to research by the nonprofit American Farmland Trust, which advocates for ​“smart solar” that doesn’t jeopardize agricultural land.

In fact, many landowners find that renting a portion of their land to solar companies can help their farming enterprise pencil out financially, reducing pressure to sell their property to developers. An acre of land, after all, may yield hundreds of dollars if devoted to crops but thousands if leased for panels.

And yet there’s no doubt that solar has grown exponentially in the state in the last decade, and that it has disproportionately displaced farmland. Cropland makes up 5% of Virginia’s total acreage but 28% of the land area now used for large-scale solar, the Virginia Commonwealth University researchers found.

Virginia’s tree canopy has also suffered under the solar onslaught. The tree canopy has  decreased 19% from 2001-2023. 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. 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. 

In Virginia, the top 11 regions for forest loss were responsible for almost 40% of all tree cover loss between 2001 and 2023. Forest loss was found in predominantly rural counties. 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.

Especially in the early years of renewable-energy construction, some companies set a poor example for responsible development, said Ashish Kapoor, senior energy and climate advisor with the Piedmont Environmental Council. ​“It was a little bit ​‘Wild West,’” he said. ​“Those early projects in 2018, 2019 — there were a lot of significant runoff issues.”

As solar fields have gone up at a breakneck pace — replacing plots of forests as well as farmland — opposition to them has also grown. Virginia localities approved 100% of solar projects in 2016, according to reporting from Inside Climate News. By 2024, the approval rate had fallen to under 50%.

Agrivoltaics — combining agriculture and solar photovoltaics — has been proposed as a potential solution, keeping  farmland in production even while it hosts solar arrays. Keeping forests alongside solar arrays is not deemed possible because of the shadowing of the solar panels by the trees.

So far the most common application of agrivoltaice has been an attempt to bring in sheep. They graze on vegetation beneath the panels and prevent the need for expensive and polluting mowers. Planting flowers in and around panels to supply honeybees and other pollinators is also popular. However, that has been perceived as more “agriwashing” than a symbiotic relationship. (Sheep were used because goats were found to climb and damage the solar panels and cows knocked them down.) Most of the solar grazing instances documented appear to be less about combining agriculture and more window dressing and saving on mowing the solar farms.

The Piedmont Environmental Council team wanted to experiment with a crop-based model because it fits better with what most farmers in the area are doing now: raising vegetables. “You want to change as little as possible for the farmer,” said Teddy Pitsiokos, who is the current manager of the farm.

 

More on the Loudoun Groundwater Assessment

The Agriculture Work Group of the Loudoun County Preservation and Conservation Coalition issued their groundwater report last month. At that time I talked about the overall conclusions: The Agriculture Work Group was alarmed not only at the drought conditions that have plagued the small well systems and resulted in water restrictions the past few summers, but also in the falling water levels in most areas. They created the report to heighten awareness of the need for proactive groundwater planning. I believe that their report demonstrates the need for Prince William County to move forward with their groundwater study and in building a network of monitoring well. Only with decades of data can the trends in water supply be measured, and yet we are already seeing troubling signs.

I would like to highlight and excerpt some sections of the report to argue for action by Prince William County moving forward with their own study and installing a well monitoring network. Before we do that, let’s cover a couple of basic points first. Groundwater is water beneath the surface of the earth. It is one of our Nation's most important natural resources and is often taken for granted. According to the USGS: “Contrary to popular belief, groundwater does not form underground rivers. It fills the pores and fractures in underground materials such as sand, gravel, and other rock, much the same way that water fills a sponge. If groundwater flows naturally out of rock materials or if it can be removed by pumping (in useful amounts), the rock materials are called aquifers.

Groundwater moves slowly, typically at rates of 7-60 centimeters (3-25 inches) per day in an aquifer. As a result, water could remain in an aquifer for hundreds or thousands of years. Groundwater is the source of about 40 percent of water used for public supplies and about 39 % of water used for agriculture in the United States.”

While groundwater is a renewable resource it is NOT unlimited. The water on earth is finite. We do not know how much water we have in the Culpeper basin, which underlies much of the western part of Prince William County, nor do we know what the sustainable rate of ground water use is. We can only hope that the Culpepper Basin is adequate to sustain the former rural crescent and the headlands of the streams in Prince William County in the next drought.  We do know that overuse of groundwater and changing land use are the biggest threats to the sustainability of our water supply.

Based on the 2023 Water Resources Monitoring Data Summary Report (Loudoun County, 2023), Loudoun County currently records groundwater levels at 20 dedicated monitoring wells (Figure 10). Seventeen (17) of these wells are operated by the Department of Building and Development and three are operated by USGS. To date over 490,000 readings have been recorded. These wells are dedicated for monitoring purposes and are not pumped.

 Assessment of the Groundwater Supply in Loudoun County      

In their report on Loudoun County ground water, the third USGS well described is located in Prince William County, just south of the Loudoun County line in the Bull Run watershed. It has collected data at this location since 1968.  The water level in this well has been declining about a foot a decade since 2000; however, it is not in a location of heavy development-yet. The Leesburg USGS well, in an area of heavier development, is declining about 3 feet per decade.

Loudoun also mentions there have been unconfirmed reports of private wells that dried up throughout the county (as there has been in Prince William). Many farmers had to start feeding hay to livestock as early as September 2024 to compensate for dried up pastures and a number of farmers began hauling water to livestock to compensate for dried up streams. To date, the Loudoun County Department of Health has identified 235 replacement wells that have been drilled in Loudoun since 2000.

Not only is the groundwater level in the monitoring wells falling, there are also other troubling signs with groundwater in the county. Records from the Loudoun County Department of Health indicate that numerous wells that were drilled with no water (i.e., dry hole) or went dry over time and were replaced. These outcomes, presumably, are due to declining water levels. There are also hundreds of wells designated as “Dry Hole” where records are less specific prior to 2001. Wells are classified as; wells that were reported to have been drilled dry, wells that are classified as Dry Hole (mostly recorded prior to 2001), and wells that are a replacement to an existing supply (presumably a shallow well or spring).

Figure 17 below shows that fundamental changes in groundwater availability have taken place in which replacement wells were required. New subdivisions exacerbate the  decline of the water table and have caused more shallow existing wells in older homes to go dry. Prince William County can expect to see more of that as they continue to increase housing density in the western portion of the county where well use is common.

 

Assessment of the Groundwater Supply in Loudoun County

In Loudoun County as of 2023, over 3,200 (almost 14%) wells have been abandoned for various reasons. Reasons include wells were no longer needed as a community water supply line was added and wells were abandoned because they have gone dry.

Groundwater wells in the Piedmont region typically intersect several fracture zones. These fracture zones are often 5 to 10 feet thick and the primary fracture zones often occur between 200 and 600 feet deep.

Climate models continue to predict that a warming world will lead to higher humidity, because warmer air evaporates more water from Earth’s surface and the air can hold more moisture (Stillman, 2024). As warming persists, evaporative and transpirative demand increases. An integrated surface water groundwater hydrologic model has been developed to evaluate the sensitivity of shallow groundwater resources to warming across most of the United States (Condon, et al., 2020)

The study  cited above shows that warming results in groundwater storage losses. In addition to global and continental scale investigations, it is important to note that researchers are also addressing regional impacts of climate change in a model analysis of groundwater in eastern Virginia (Culver, et al., 2025). There are two reasons for citing this research. First, is that other researchers acknowledge that climate change is affecting water resource availability in eastern Virginia now, not centuries from now. Second, is that the researchers believe that precipitation variability that results in more drought conditions is causing them to reassess the sustainability of groundwater resources for water supply within a Virginia Groundwater Management Area and this is likely to impact the Culpepper Basin and surrounding surface water flow volume.

Mankind’s hand in changing the land surface impacts water resources. Land use changes that increase impervious cover, add more suburban lawns, roadways, buildings, pavement and eliminates woodlands reduces groundwater recharge and increases stormwater flooding. Land use changes also potentially increases the use of groundwater by adding more homes and businesses (like Amazon who reports drawing millions of gallons of groundwater in the Manassas area).

Slowly, the changes in land use change the ecology of the watershed and can reduce the water supply over time. As groundwater levels fall, perennial steams that feed the rivers become intermittent during dry periods like the last few summers. I believe this is what is happening in the area of the Bull Run Mountain Conservancy where for the second summer in a row, what where perennial streams have stopped flowing in the summer.

Generally, groundwater in the Culpeper Basin is renewed each year through precipitation. The water stored in the watershed has always been able to provide adequate water in droughts because historically the withdrawal of water was within the average recharge rate. However, the only nearby USGS groundwater monitoring well is no longer stable. The water level has been slowly falling since before the last drought- despite a series of wet years.

Groundwater recharge through precipitation requires adequate area for infiltration; control of sheet flow created by roads and paved areas, as well as protecting the most geologically favorable infiltration points. In a natural environment much of the precipitation soaks into the ground. Some water infiltrates deep into the ground and replenishes aquifers, which store huge amounts of freshwater for long periods of time. Some infiltration stays close to the land surface and can seep back into rivers, creeks, and ponds through the hyporheic zone.

Maintaining open areas provides areas of groundwater recharge. According to the U.S. Environmental Protection Agency, impervious cover levels of less than 5%-10% can significantly impact watershed health increasing stormwater runoff and reducing groundwater recharge. When runoff volume increases, runoff velocity increases, and peak storm flows increase and you get flooding with soil erosion, fast moving stormwater carrying contamination and reduced or eliminated water infiltration into groundwater. The groundwater is essential as the base flow to the streams and rivers that feed the Occoquan Reservoir during the dry months. Is this a little hint of the beginning of the end.

The bottom line is our water supply may not be sustainable and is certainly not sufficient when increasing impervious surfaces and increasing demand by adding data centers and population. We are headed for disaster, but so slowly that we can continue ignore all the signs until disaster is upon us.

Vint Hill Small Area Plan

Prince William county is promoting regressive land use policies and practices, those from a time when we did not know all water is connected. Increased development in the Occoquan watershed as seen in the outline of the Vint Hill Small Area plan will increase paved surfaces and runoff and decrease forested and agricultural land that allow groundwater recharge and store water. The result will be an increase in salinity and chemical and sediment contamination and decrease in streamflow. in the Occoquan watershed.

from USGS

Since 2001 we have added all the “red” impervious surfaces. From 2014 to 2021 Prince William County has lost almost 2,000 acres of trees. No one knows what has been knocked down in the past 4 years of unrestrained development and land clearing.

slide prepared by Vida Carrol  for her PWCA presentation

So let’s talk a little bit about what’s planned. There are currently 7 rezoning plans already in progress: Strathmore, Silver Bell, the Villages at Broad Run, the Greens at Broad Run, Longleaf at Kettle Run, Alderwood at Kettle Run and Hawthorn at Kettle Run. On Wednesday, October 15^th , Longleaf at Kettle Run, Alderwood at Kettle Run and Hawthorn at Kettle Run will be heard at the planning commission. Together these three total 1,123 acres and will have 1059 housing units (townhouses and single-family homes) built.

It is likely that the drinking water for the development in the small area plan will come from the western system of Prince William Water  that is supplied primarily from the Potomac River via Fairfax Water from the Corbalis Plant (PW Water also draws from Lake Manassas for the Western system). Drinking water for Woodbridge, Occoquan, Dumfries, Triangle and Hoadly Manor comes from the Occoquan Reservoir via Fairfax Water Griffith plant which serves the customers in the eastern portion of Fairfax Water’s service area and the Eastern Distribution System of the county (in the Pink). Water from the Occoquan Reservoir supplies the Griffith treatment plant. The Occoquan Reservoir supplies water to nearly a million people.

Prince William County holds about 44% of the Occoquan Watershed; but more importantly, the Occoquan Watershed is more than two thirds of Prince William County land. Decisions made in Prince William County will impact all the customers of Fairfax Water and the nearby users of groundwater. To properly protect the Occoquan Watershed and the regional water supply you need to know what the impact of development will be.  

from NVRC

The Occoquan Watershed Model was developed over decades as we learn more to evaluate the impact of land use decisions and compare potential land use scenarios and their impact on the Occoquan Reservoir water quality. Prince William County helped pay for the creation of that model, but has not yet received the results of the latest study- they are planned to be delivered late this year. Though, Prince William County declined to provide the development plans for the scenarios.  Nonetheless, the Board of County Supervisors approved the changes to the comprehensive plan that did away with the Rural Crescent and wholesale change in the land use of the county without even considering what the impact will be on our water supply. Each supervisors meeting seems to rewrite the comprehensive plan and they do not want to look at the damage their decisions are projected to make to the Occoquan Watershed and ultimately the quality and quantity of water to the Occoquan Reservoir.

Prince William County and the Board of County Supervisors have also failed to consider the impact of the proposed zoning changes to the quality, availability and sustainability of the groundwater as they are required to do under the Comprehensive Plan law.   Nor did they consider the impact on meeting goals for the Chesapeake Bay pollution diet.

This is the average flows to the Occoquan Reservoir from each of its sources:

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

The region’s water supply is under threat. Pave over the sub-watersheds and you eliminate the streamflow.  Our woodlands are fast giving way to impervious surfaces, impacting the water tables and the ecosystem exacerbating drought.  Research by the Chesapeake Bay Program shows that Prince William County and Loudoun County have lost nearly 5,400 acres of tree canopy to development over just seven years due to human development. The threats to tree canopy include; the construction of utility scale solar arrays, warehouses, data centers road expansions and electrical transmission lines.  The loss of trees reduces the recharge of groundwater which in turn reduces stream flow. The volume of natural freshwater for drinking reduced and episodic storm water flooding increases. There is no mechanism on earth for making more water, we have only what falls from the sky and is stored in the land.  Disrupt the water cycle and you change the ecology.

As Dr. Stanley Grant, director of the Occoquan Watershed Monitoring Laboratory, made clear at his presentation to the PWC BOCS,  emerging water quality issues are a result of the “built” environment. As we continue to develop the Occoquan Watershed we endanger the sustainability of the water supply for up to 1 million people in northern Virginia. When population density increases, the impervious surfaces in a watershed increase. However, the increase is not linear, once the population density reaches 100 people per square mile, the rate of increase in impervious surfaces increases rapidly. This is what will finally turn the most urbanized watershed in the United States into a memory. 

The salinity in the reservoir has been rising over time and may be reaching a critical stage.  The rising salt in the reservoir is primarily from watershed runoff (salting roads) during wet weather and reclaimed water from UOSA during dry weather. Sodium concentration in the reclaimed water from UOSA is higher than in outflow from the two watersheds right now and will rise with the increase in blowdown from data center cooling and increased population density. Along with the salt are all the trace chemicals that we pour down the drain, flush down the toilet and pass through us. However, increasing paved areas increases the salt runoff into the watershed, so that will increase also.

The only way to remove salt from the drinking water supply is to invest billions of dollars (from your water rates) in building and installing desalination equipment in the region’s water treatment plants which are not currently capable of removing salt from the source water. There is no other source of water to supply our area. The costs to add treatment lines at Fairfax Water to keep the Occoquan Potable is estimated to cost between $1 and $2 billion. This is a cost that will be borne by the water rate payers including the 350,000 public water users in Prince William County.

Prince William County is on a tear to build housing throughout the open land in Prince William County. The belief that we need more housing has overridden any concern for the watershed and the Board of County Supervisors did not even consider the impact of continued development to the health of the watershed. The Occoquan watershed is often described as the most urbanized watershed in the nation. Think about that for a minute, certainly there are far more urbanized areas in the United States, but they do not have functioning watersheds. During their growth and development cities across the nation from New York, to Philadelphia through Baltimore and Washington, confined and subsumed many thousands of streams, erasing them from memory and destroying the watersheds.

Scientists have found that land use management can enhance or destroy stream water quality.  Particularly they found that when 5-10%  of a watershed is developed it begins to die, but can still be restored for a while. If urban land use exceeds the tipping point water quality does not respond to restoration measures. Once you destroy a watershed we do not know how to restore it.

Before we do irreversible harm to the ecology and our regional drinking water supply, we need to look at what the impacts of planned changes will be to the water supply. The cost to restore the basin and treat the water is in the billions of dollars that will be borne by us, the residents. In the future may be too late to protect this essential portion of our water supply. No analysis has been done as to the potential impact of these developments to the hydrology of the Occoquan Watershed.  There is no understanding what the impact this might have to the quality and quantity of water to the Occoquan Reservoir. Yet the Occoquan Reservoir is irreplaceable for the region.  

Land use changes that increase impervious cover more than 5-10% from roads, pavement and buildings does two things. It reduces the open area for rain and snow to seep into the ground and percolate into the groundwater and the impervious surfaces cause stormwater velocity to increase preventing water from having enough time to percolate into the earth, increasing storm flooding and preventing recharge of groundwater from occurring- Increasing flooding.

Slowly, over time, this can reduce water supply. As groundwater levels fall, perennial steams that feed the rivers become ephemeral. The groundwater becomes disconnected from the surface water network. Once the hydrology is destroyed by development, it cannot be easily restored, if at all. The chart below shows the percentage of the Occoquan Watershed that was impervious in 2015. Overall, we were already at 10%  impervious cover. Lower Bull Run was at 24% and Lower Broad Run was at 13%. Upper Broad Run, Upper Bull Run and Cedar Run were providing all the open space for recharge to the watershed. Now, the push is on to cover the undeveloped upper watersheds with impervious surfaces.

NVRC 

Prince William County and the Board of County Supervisors talk constantly about the need for more housing. Whether of not that is true, we cannot build in the open land in the Occoquan Watershed if we still want to have sustainable drinking water. Period.

Land Use Changes in Chesapeake Bay Watershed

 This past summer the  Chesapeake Bay Program released an update to its High-Resolution Land Use/Land Cover Data and Change Data and, for the first time, Hyper-Resolution Hydrography Data that precisely identify the location, dimensions and connectivity of streams, ditches and other waterways.

The updated Land Use/Land Cover Data, allows us to look at the changes in land use and land cover from 2001-2019. This tool was designed to see how the land of the Chesapeake Bay watershed is being managed and how it’s changed over time, it can also be used to look at the smaller watersheds that makeup the larger Chesapeake Bay watershed. The data is available to everyone, including county and state planners and conservation groups. The data can be widely used to address community planning, conservation efforts, human safety planning around flooding and environmental restoration efforts across the Chesapeake Bay, Potomac River and the Occoquan Watersheds.

The hydraulic and tree cover data were produced by the University of Maryland, Baltimore County (UMBC) in collaboration with the Chesapeake Conservancy Conservation Innovation Center. The University of Vermont Spatial Analysis, Chesapeake Bay Program and the USDA Forest Service also participated in the project. The U.S. Geological Survey (USGS) helped secure funding for the work, and stewarded the data products through the USGS peer review process.

In general, developed lands in 2001 were more concentrated within towns and major metropolitan areas. Since 2001, developed and semi-developed lands have expanded around these urban areas, as well as extending into previously undeveloped regions. How this has impacted Prince William County can be seen in the map below where the gray area shows where the land was covered by impervious surfaces in 2001, and the red area shows impervious surfaces developed between 2002 and 2019.

Land development 2001-2019 in Loudoun and PW counties

The proportion of land in the Potomac watershed classified as urban rose from 10% in 1985 to 17% in 2021 as identified in the Chesapeake Assessment Scenario Tool. This is problematic. Land use changes that increase impervious cover more than 5-10% from roads, pavement and buildings does two things. It reduces the undeveloped area for rain and snow to seep into the ground and percolate into the groundwater and the impervious surfaces cause stormwater velocity to increase preventing water from having enough time to percolate into the earth, increasing storm flooding and preventing recharge of groundwater from occurring. 

Slowly, this can reduce natural water supply over time and this is the watershed for our drinking water supply. As groundwater levels fall, perennial steams that feed the rivers become ephemeral. The groundwater becomes disconnected from the surface water network. Once the area hydrology is destroyed by development, it cannot be restored. Though there have been a few attempts, mankind has not succeeded in restoring a watershed. 

The research shows that Prince William County and Loudoun County have lost nearly 5,400 acres of tree canopy to development over just seven years due to human development. The emerging threats to tree canopy in Virginia include; the construction of utility scale solar arrays, warehouses, data centers road expansions and electrical transmission lines. 

Prince William County had PW Forest Park as a significant portion of tree cover

from Chesapeake Tree Canopy Network

When the land use changes completely to something other than forest, pasture or agriculture, then you lose the infiltration ability of the land and maintain the health of the rivers, stream and the land itself. The data set did not capture the acceleration of development in our region since 2021. The biggest solar operations and data center campuses in Virginia were installed after the most recent mapping imagery was captured, currently under construction or still in development but approved. Landscape changes like these are considered permanent. 

Conowingo Dam Agreement Reached (again)

Last Thursday, Governor Wes Moore announced an agreement with Constellation Energy to fund and implement operational improvements and some environmental projects at the Conowingo Dam. The total commitments are valued at more than $340 million and were negotiated in partnership with Waterkeepers Chesapeake and Lower Susquehanna Riverkeeper Association. A previous $240 million agreement with the former dam operator was challenged in court by the Riverkeepers and Waterkeepers.

“The Chesapeake Bay is the keystone to Maryland’s prosperity,” said Gov. Moore. “This agreement will lead to real improvements in water quality in the biggest tributary of the Chesapeake Bay, while securing the future of one of our state’s largest clean energy producers. By bringing everyone to the table, we have struck an agreement that is good for the environment, good for energy production, and good for Marylanders.”

The agreement clears the way for the re-licensing and continued operation of the dam’s hydroelectric facility on the Susquehanna River, which is the largest source of renewable energy in the state. The terms of the agreement, announced today at the dam, include operational improvements and upfront and ongoing annual payments: 

• Water quality and resiliency: $87.6 million for pollution reduction and resiliency initiatives, including shoreline restoration, forest buffers, fish passage projects and planting underwater grasses that produce oxygen, stabilize sediments and provide habitat for countless species.

• Trash and debris removal: $77.8 million to improve trash removal program that currently clears an average of about 600 tons of debris each year.

• Aquatic life passage: More than $28 million for fish and eel passage improvements and protections at the dam, helping American shad, river herring, and freshwater mussels rebound while reconnecting habitats across the Susquehanna.

• Freshwater mussel restoration: $23.3 million to build and operate a hatchery that will seed the river with mussels, which are natural filters that clean the water and reduce pollution flowing into the Bay.

• Dredging: $18.7 million for additional studies on dredging.

• Invasive species management: $9.4 million to control destructive species like snakeheads and blue catfish, protecting the river’s ecosystem.

• The Lower Susquehanna Riverkeeper Association and Waterkeepers Chesapeake will have an ongoing role in aspects of the implementation of the certification and settlement agreement.

“This historic agreement ensures that our children and grandchildren will inherit a Chesapeake Bay and Susquehanna River that are cleaner and healthier than they are today,” said Attorney General Anthony G. Brown. I do not know if this is indeed a historic agreement, but it does seem better than the last one that failed.

“This deal ensures we balance the importance of generating renewable energy while protecting water quality standards and the broader ecosystem,” said Maryland Department of Natural Resources Secretary and Chesapeake Bay Program Principals’ Staff Committee Chair Josh Kurtz. “The settlement will allow us to apply the innovative strategies we developed restoring oysters in Chesapeake Bay tributaries to bring back water-filtering mussels in the Susquehanna River basin and other freshwater rivers in Maryland. Thank you to everyone who helped us reach this agreement.”

The Conowingo Dam is a large hydroelectric dam on the Lower Susquehanna River about 10 miles upstream from where the river flows into the Chesapeake Bay at Havre De Grace, Maryland. Not only is the Conowingo Dam the largest source of renewable energy in Maryland, the three dams at the downstream end of the Susquehanna River have been important in mitigating the downstream transport of nitrogen, phosphorus, and suspended sediment from the Susquehanna River watershed to the Chesapeake Bay. The Conowingo, the last dam in a series of three traps polluted sediment from the Susquehanna River in its 9,000-acre reservoir.

When the Chesapeake Bay Total Maximum Daily Load (Bay TMDL) was established in 2010, it was estimated that the reservoir behind the Conowingo Dam would trap sediment and associated nutrients through 2025. However, the reservoir reached dynamic equilibrium (i.e., the reservoir is near full capacity) more than a decade earlier than thought

The Conowingo Dam can no longer trap additional sediment in the Susquehanna River and prevent them from entering the Chesapeake Bay. That is what dredging studies are about. If it is feasible, the dredging could allow the Conowingo Dam to once more capture the nitrogen, phosphorus and sediment washed into the river by rainstorms.

The Susquehanna River flows 464 miles from Cooperstown, New York to Havre De Grace, Maryland collecting sediment and nutrient runoff along the way. The Susquehanna drains an area of more than 27,000 square miles and is the single largest source of fresh water flowing into Chesapeake Bay. The river currently provides nearly half of the Bay’s freshwater, 41% of its nitrogen, 25% of its phosphorus and 27% of its sediment load. Without the Conowingo removing sediments containing nitrogen and phosphorus the reductions in sediment, nitrogen and phosphorus necessary to meet the goals of the Chesapeake Bay Agreement will have to come from somewhere else.

Let’s be honest here. Implementation of the various state’s watershed plans to reduce nitrogen, phosphorus and sediment in the Chesapeake Bay failed to meet the targets set in 2012. In addition, climate projections for our region forecast that on average, precipitation in the region  is projected to increase by around 8% by 2040, and temperature is projected to increase by 2.16 °C (3.9 °F). “Because warmer air can hold more moisture, heavy rainfall events ...are projected to increase in frequency and severity as the world continues to warm. Both the intensity and rainfall rates of Atlantic hurricanes are projected to increase with the strongest storms getting stronger in a warming climate. …”  says the Fourth National Climate Assessment.

The bottom line here is the Conowingo Dam cannot be left full. It will not exist in some gentle equilibrium. The Conowingo and its sister reservoirs will not be constantly filled with sediments because of short-term changes from severe storms that cause scour and a subsequent reduction in exported sediments until the scoured amount is refilled. Therefore, the amount of sediment transported out of the reservoirs will not always be in equilibrium with the amount of sediment transported into the reservoirs. Dredging does seem to be the answer, but there are so many problems with the source water for the region; we need to indeed study the issue.  

See Also: Hirsch, R.M., 2012, Flux of nitrogen, phosphorus, and suspended sediment from the Susquehanna River Basin to the Chesapeake Bay during Tropical Storm Lee, September 2011, as an indicator of the effects of reservoir sedimentation on water quality: U.S. Geological Survey Scientific Investigations Report 2012–5185, 17 p.

Vanished Artesian Wells

Hilton A, Jasechko S. Widespread aquifer depressurization after a century of intensive groundwater use in USA. Sci Adv. 2023 Sep 15;9(37):eadh2992. doi: 10.1126/sciadv.adh2992. Epub 2023 Sep 13. PMID: 37703375; PMCID: PMC11006208.

Widespread aquifer depressurization after a century of intensive groundwater use in USA - PMC

Leonard O Ohenhen, Manoochehr Shirzaei, Patrick L Barnard, Slowly but surely: Exposure of communities and infrastructure to subsidence on the US east coast, PNAS Nexus, Volume 3, Issue 1, January 2024, pgad426, https://doi.org/10.1093/pnasnexus/pgad426

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

Flowing artesian wells are defined as wells where groundwater flows to the land surface without pumping. Flowing artesian conditions can arise in wells that tap unconfined aquifers or those that tap confined aquifers. Flowing artesian conditions were more widespread in the 19^th and early 20^th century than they are today, I am old enough to recall when an artesian well flowed not too far from where I sit now.

As our country developed these flowing artesian wells were used to supply water- irrigate farmlands, provide safe and inexpensive drinking water, and support businesses. This was the first groundwater we could tap without the available pumps and power of today. Groundwater sustains food systems and provides drinking water to millions of people in the US today, but most of the flowing artesian wells are gone.

Flowing artesian conditions indicate that there is a sufficiently high hydraulic head for upward-oriented groundwater flow. Upward-oriented groundwater flows may protect deep drinking water from downward transport of surface-borne pollutants (6). The loss of flowing artesian conditions and upward-oriented groundwater flows demonstrate depressurization of an aquifer. Depressurization can change groundwater flow patterns over large areas, affecting the solute distribution sin aquifers. Depressurization can also alter an aquifer’s skeletal structure by the compression and compaction of confining units, resulting in land subsidence and the loss of groundwater storage, especially in aquifer systems with fine-grained unconsolidated sediments.

Despite their importance to groundwater-dependent ecosystems and human water access, no continent-wide study had quantified how prevalent flowing artesian conditions once were or how they have changed over the last century. In the above cited study, the  researchers compiled thousands of water level measurements from US Geological Survey reports published in the early 1900s and compared these measurements to modern well water level measurements. They developed two complementary analyses to quantify change over time in flowing artesian conditions at the regional and continental scale and examined them for the eight regional aquifer systems of the continental United States.

In six of the eight regional aquifer systems, they found that flowing artesian conditions were common a century ago.  In the pre-1910 dataset 48% to 100% of wells were flowing artesian). Today, however, fewer than 10% of wells are flowing artesian (in our post-2010 dataset. These six systems are:

• Dakota Aquifer System (where the proportion of wells that exhibit flowing artesian conditions declined from 93% to 9% over the past century;
• North Atlantic Coastal Plain Aquifer System (declined from 83% to 0.8% over the past century;
• Mississippi Embayment Regional Aquifer (declined from 48% to 0.5% over the past century;
• Houston-Galveston area within the broader Gulf Coast Aquifer System (declined from 96 to 0% over the past century; 
• Roswell Artesian Basin in southeast New Mexico (declined from 100% to 0% over the past century; 
• California Central Valley (declined from 77% to 0.2% over the past century; 

Flowing artesian wells were also common over a century ago in the Floridan Aquifer System (58% of wells in our pre-1910 dataset). Contrasting the four above aquifer systems, the Floridan Aquifer System has retained an ability to support flowing artesian conditions at present day (17% of wells exhibit flowing artesian conditions in our post-2010 dataset). The wells that exhibit flowing artesian conditions are concentrated along the coasts, whereas flowing artesian wells are nearly nonexistent farther inland. The proportion of wells exhibiting flowing artesian conditions declined considerably from 58% of wells to 17% in our post-2010 dataset.

Flowing artesian wells were not common in the Columbia Plateau Regional Aquifer System before 1910. In our pre-1910 dataset, just 2% of wells that tap confined aquifers exhibit flowing artesian conditions, and 1% of wells are flowing artesian in our post-2010 dataset. The pre-1910 Columbia Plateau Regional Aquifer data shows that not all confined aquifers supported flowing artesian wells a century ago.

Flowing artesian wells have served humanity for centuries. In the US, flowing artesian wells enabled settlements, supported livelihoods, and provided safe and equally available drinking water supplies to settlers and indigenous peoples.  The analysis found a substantial reduction in the prevalence of flowing artesian conditions across the US (~61% in our pre-1910 dataset, to ~4% in our post-2010 dataset. The results provide evidence for a widespread depressurization of confined aquifer systems.

The decline in flowing artesian conditions may imply a reversal of groundwater flow directions from natural upward-oriented flow to the modern-era where there is a greater likelihood for downward-oriented flow. These reversed vertical groundwater flow directions and depressurized aquifer systems have likely increased the potential for contamination in deep aquifers and induced land subsidence. The analysis reveals that flowing artesian wells have been extinguished over a century of groundwater use in the US, affecting aquifer systems and humans that rely on artesian aquifers.