Wednesday, March 29, 2023

Sustainable Water

 On Tuesday, the Committee of 100 held:

A Panel Discussion on the Quality & Quantity of

Water Resources in the Prince William Area

I was honored to be one of the Panelists along with Dr. Stanley B. Grant, Professor and Director of the Occoquan Watershed Monitoring Laboratory (OWML), Greg Prelewicz, Planning Manager at Fairfax Water, and Lazaro Gonzalez, Director of Global EHS and Sustainability, Micron Technology. Below are my comments:

As seen from space, we are the blue planet covered with water.

Yet, there is no mechanism on Earth for creating or destroying large quantities of water.

The most fascinating thing about water is that the water we have is what's been here, literally, forever- since the planet was formed 4.5 billion years ago.

Though 3% of the water on earth is fresh, only ½% of the water is available for us to use. The rest of the fresh water is locked away in ice, super deep groundwater or polluted beyond redemption.

The available supply of fresh water is renewed by the hydrologic cycle or artificially replenished by the activities of mankind.

In its most simplistic terms Rain drops fall to earth and will either evaporate, infiltrate into the soil, recharge groundwater or flow along the ground to a stream and ultimately flow into rivers and to the ocean-moving always moving.

But many activities of mankind interfere with the hydrologic cycle

The need for water is constant and grows with population and wealth

A community or society becomes unstable if water resources are inadequate to meet the needs of the community by growth in demand or reduction in supply- often both.

The Potomac River, its tributaries, reservoirs and the associated groundwater resources are the source of drinking water for the over 6,000,000 people in the Washington Metropolitan area.

A little more locally, the Potomac River and the Occoquan Reservoir are the main supply of water for Fairfax Water which also supplies Prince William Service Authority and American Water

Water supply in Prince William County is a mix of water from the Occoquan Reservoir, the Potomac River, groundwater and Lake Manassas.

And yet our water supplies are connected to each other and the land

The Occoquan Reservoir was built 1960’s expanded to its current capacity in the 1980’s.

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 confined and subsumed many thousands of streams, erasing them from public memory leaving only stormwater.

Water comes into the Occoquan water basin from rainfall (and melting snow) . The streams and creeks of the watershed come together at Bull Run and the Occoquan River to deliver the water to the Reservoir. Groundwater is part of this system maintaining the base flow of the rivers.

There is no longer enough water in the rivers to meet the demand, the Upper Occoquan Service Authority, UOSA, -the waste water treatment plant also delivers 40 million/day of recycled water that originated in the Potomac River to the Occoquan Reservoir. Supplementing the supply.

Our Climate is changing. Locally, average rainfall has been increasing. Over the last 30 years it increased slightly to approximately 44 inches per year. Climate forecasts for our region by the ICPRB project us to get wetter with more intense rainstorms - and droughts to become more severe.

Increased rainfall may not bring us more water. Land use changes also impact our water resources. Increasing impervious cover from roads, pavement and buildings does two things:
  1.  It reduces the open area for rain and snow to seep into the ground and percolate into the groundwater and.
  2.  The impervious surfaces cause stormwater velocity to increase and the amount of stormwater runoff to increase more the 5 times. The result is Flooding and diminishing groundwater.

Changing land use and increased rainstorm intensity results in flooding. Stormwater runoff increases in quantity and velocity washing away stream banks, flooding roads and buildings carrying fertilizers, oil and grease, and road salt to the Occoquan Reservoir.

Here in the only USGS groundwater well in the rural area you can see both the seasonality of water, but also the slowly falling groundwater level since 2004. Despite extremely high rainfall in the last few years.

Increases in groundwater use and reduction in aquifer recharge can result in the slowly falling water levels that appear to be showing that our groundwater is being used up. This will impact stream flow.

The changing land use impacts the regional hydrology and groundwater recharge so the quantity of available groundwater and streamflow decreases over time.

The Rural Crescent created in 1998 was eliminated in 2022 by the BOCS adoption of the new comprehensive plan.

Despite available tools, Prince William County did not study the impact of the proposed changes to the quality, availability and sustainability water supply as they are required to do under the Comprehensive Plan law. Nor did Prince William County study the impact of the proposed changes to compliance with the WIP III mandated under the Chesapeake Bay TMDL.

Fairfax Water took the unusual step to ask that Prince William County convene the Occoquan Basin Policy Board and oversee a Comprehensive Study of the impacts on water quality and quantity of the planned land use changes in PW Digital Gateway CPA and the 2040 Comprehensive Plan Update before any action is taken. They declined. 

Sunday, March 26, 2023

Urbanization’s Impact on Stream Water Quantity and Quality


Impacts of urbanization on stream water quantity and quality in the United States | Publications | SRS (

Researchers at the U.S. Department of Agriculture Southern Research Station have for some time been studying the impact of urbanization on our water resources. As we are moving ahead with the industrialization, and residential development of the Occoquan Watershed. I though it might be useful to summarize the work of two of the researchers, Ge Sun and Peter Caldwell. The below is excerpted from their article:

Sun, Ge; Caldwell, Peter 2015. Impacts of urbanization on stream water quantity and quality in the United States. Water Resources Impact, Volume 17 Number 1. 4 p.

In the United States 80% of the population lives in urban areas. The most obvious and direct impact of urbanization on watersheds is altering the hydrologic cycle that controls the flow of water in ecosystems. Manmade structures such as irrigation canals, wells, reservoirs, dams, and paved roads have shaped the natural watershed landscape.  Though there are still gaps in our understanding of the interactions among processes associated with urbanization (land conversion, increasing impervious areas, new pollutants), hydrological functions (water budget change and infiltration), and ecological functions (biota change) and the time scale of impact, we’ve learned much in recent decades. It is clear that rising populations and increased development pose major threats to our future water supply.

Converting forest lands and natural landscapes to urban uses increases the surface reflection of solar radiation, enhances storm intensity, and causes heat island effects (O’Driscoll et al., 2010). Removing forest and natural vegetation cover reduces plant transpiration, and reduces water’s ability to infiltrate into soil and the soil’s ability to accept the water. These factors result in a dramatic increase in stormwater overland flow.

To maintain water supply from an urbanized watershed requires some combination of factors such as infrastructure renovation, improved design and scale of new water and sanitation treatment systems, and expanded implementation of watershed services management will be needed. Urbanization dramatically increases population and the demand for water; and affects ecosystem processes, and as a result, water quantity and quality in streams. Alterations of watershed hydrologic cycles are the root causes of the stream ecosystem degradation observed in urban landscapes.

The Impacts of urbanization on water quality are primarily caused by two key factors – significant production of pollutants and reduction of retention capacity of the watersheds as a result of increased impervious surfaces (Sun and Lockaby, 2012). Conversion of portions of watersheds from forest to urban cover often elevates sediment and nutrient concentrations by tens to hundreds of times.

The threshold of impervious surfaces at which water quality and flow changes occur is 5%-20%. In addition to sediment and nutrients, other concerns to human health are that urban waters often contain pharmaceuticals such as antibiotics, analgesics, narcotics, and psychotherapeutics, pesticides, heavy metals, pathogenic microbial populations, and organic pollutants.

Protecting water resources across urbanizing landscapes requires management of land cover at the watershed scale by adopting urban best management practices (BMPs) and protecting source headwaters. The contemporary watershed management goal is to prevent development beyond the critical point which varies based temperature, rainfall, and geology; or otherwise, minimize impact in critical locations that are particularly sensitive to water quality and quantity. Although difficult to quantify, the opportunity cost of maintaining forest land cover in a watershed is likely less costly than allowing urbanization to occur, increasing storage and applying conventional approaches to water treatment to mitigate the water quality impairment.

In order for us to have a sustainable, adequate and quality water supply, we need to ensure that the source water of the Occoquan Reservoir is protected. Prince William County needs to convene the Occoquan Basin Policy Board and oversee a Comprehensive Study of the impacts on water quality and quantity of the planned land use changes in the county before do irreparable harm to our source water supply.

Wednesday, March 22, 2023

Distributed Solar


Solar parking structure at METRO station

In 2018 Virginia was identified as one of the states that is not utilizing their technical potential for rooftop solar. Since that time Virginia passed the VCEA, the Virginia Clean Economy Act. State incentives a well as the mandates could help build solar. However, utility scale solar farms may not be the only or best answer. Distributed solar as part of a series of microgrids along with solar farms built on brownfields or closed landfills can be used to achieve the goals of the VCEA without building on more fragile ecosystems in our essential watersheds.

Proposed site for a solar farm in Bull Run Watershed

For instance the Washington, D.C., Metro transit system has recently contracted to build solar canopies at four of its rail station parking lots, with a projected capacity of 10 megawatts. This has been in the works for several years.  After extensive planning Metro negotiated a 25-year contract with TotalEnergies to install and MN8 Energy LLC. to own and operate solar carports at four Metro sites. 

When the solar carports are completed and operational, the 11 acres of solar panels (equivalent to 8 football fields) will collectively generate around 10 megawatts of electrical capacity. This is a first step, but still, this project one of the largest community solar projects in the Mid-Atlantic region and in the nation. Community solar may be the way of the future.

Commuter parking lots, the parking lots and rooftops of the rapidly spreading commercial and industrial development in Prince William and Loudoun Counties are potentially all locations for solar. Commuter and community parking with solar and EV charging stations could also address some of the challenges with the replacement of internal combustion automobiles with electric vehicles.  

Construction cost are higher for solar-powered parking structures with EV charging than for a rural solar “farm.” The physical structures need to be taller and more robust than a conventional solar farm, requiring more materials like metal and concrete; however, utilizing existing parking lots with existing stormwater management infrastructure reduces those costs. EV chargers also cost money, but addresses the need for accessible EV charging infrastructure for diverse populations and communities.   

Southern Avenue under construction

Sunday, March 19, 2023

Solar Farm Proposed for Logmill Road


aerial view of the property from Historic Prince William

Inside NOVA and several other local sources have reported that a 20 megawatt solar farm is proposed for the Gainesville district of Prince William County. I am a little more specific with location so that neighbors can take a closer look.

The project identified in the planning que as Waterloo Solar, #SUP2023-00008 Gainesville District is a Special Use Permit (SUP) request.  The property is located at 2539 Logmill Road, Haymarket, on the north side of Logmill Road approximately ±772 feet west of James Madison Highway (Route 15). This property is currently owned by William and Elizabeth Latham. It was previously owned by the estate of William Latham Sr.

The SUP is to use 125 acres out of a total ±232.26 acres for a solar farm. They need a SUP because the property is designated as Agriculture and Forestry, AF, and Environmental Resource Protection Overlay, ERPO, in the new Comprehensive Long-Range Land Use Plan Map. A portion of the site lies in the 100-year Flood Hazard Overlay District and the Chesapeake Bay Act Resource Protected Area. The surrounding areas to the north, east and west are also designated as Agriculture and Forestry, AF, in the Long-Range Future Land Use Map and are occupied by single family residential homes and farmland. Under the old comprehensive plan they were all A1 zoning.

the subject property with Parnell Court to the left

The proposed project is for the life of the solar panels, 35 years. According to the Planning department the proposed use will reduce available land for crop agriculture and could impact runoff and erosion of the land with the added access roads and land disturbance. However, the proposed site layout seen below preserves environmentally constrained areas as well as specimen trees and does not propose clearing forested areas. In addition, the applicant has proposed a possible other agricultural form of use of the land - livestock grazing in certain areas to get around the zoning issue. Mr. Latham is a farmer and grazes cows in other locations in Haymarket. (One of which is more or less behind my house.)

from the SUP submission

According to the Planning department “For this use to be lawfully permitted on the subject parcel, one of the following two actions must take place: 1. Proof of continuation of farming through a valid bona fide agricultural use determination; or 2. Subdivide residentially used property from residual land proposed for solar energy facility use.”

Planning has suggested several mitigations to address concerns; however, recently Prince William County has a history of either waving, modifying or removing mitigations at the last minute (literally at some recent all night public hearings at dawn) so I have a certain uneasy feeling about this.

The planning department suggests that all on-site utility lines shall be placed underground to the extent feasible and as permitted by the serving utility, except for the main service connection at the utility company right-of-way and any new interconnection equipment, including without limitation any poles, with new easements and right-of-way. The facility would sit on 125 acres of the property and produce 20 megawatts of electricity. It will be interconnected with the Northern Virginia Electric Cooperative grid. The type of interconnection necessary for a power generation facility is not discussed. Nor is there any discussion of what that will look like. This matters, especially to the lovely homes surrounding the property and the visual byway that Rout 15 is supposed to be.

The project would include a 100-foot setback from all property lines and the height of solar panels would be capped at 9 feet. However, the site restrictions read: “No aspect of the facility shall exceed 25 feet in height, as measured from grade at the base of the structure to its highest point. Solar panels shall not exceed 13 feet in height above grade, from the highest grade around the structure.” The planning department asks the site developer, HCE Waterloo Solar LLC, to provide a visual assessment of the visual impacts of the proposed solar energy system from public roadways and adjacent properties.

Planning stipulated that "Except for motion activated safety and security lighting, which shall be downward facing, the Facility shall not be lit. Lighting shall not exceed fifteen (15) feet in height. Compliance shall be demonstrated on the final site plan."

In addition, Environmental Services asks the developer to “Guarantee to develop, implement, and maintain native vegetation to the extent practicable pursuant to a vegetation management plan by providing native perennial vegetation and foraging habitat beneficial to game birds, songbirds, and pollinators. Plant buffers with vegetation that benefit pollinators and early successional species around the boundary of the solar energy system.”

Environmental Services points out that “there are extensive RPAs throughout the parcel, but the existing conditions lack any effective vegetation. Please commit to reforesting the RPAs throughout the project area. The Riparian Buffer Guidance Manual has planting standards that should be used and referenced in a SUP Condition committing to this restoration. Staff also recommends the Applicant commit to a minimum 2-year invasive plant control period to help ensure new plantings are not overcome by non-native invasive vegetation.” This could be an important mitigation in this particularly sensitive portion of the Occoquan Watershed. It is important to make sure it actually happens. 

Generally, the developer appears to be laying out the solar arrays to avoid sensitive environmental features, but this effort needs to be clearly demonstrated on the SUP Plan. Not empty promises that will be waived or removed at the last minute. In addition, a stormwater management plan is very necessary for the site. Solar panels increase stormwater velocity and this needs to be addressed.

Wednesday, March 15, 2023

EPA proposes drinking water standards for PFAS

On Tuesday the U.S. Environmental Protection Agency (EPA) announced its long awaited proposal for the national drinking water standard for six per- and polyfluoroalkyl substances (PFAS) . 

  • PFOA and PFOS: EPA is proposing to regulate PFOA and PFOS at a level they can be reliably measured at 4 parts per trillion.
  • PFNA, PFHxS, PFBS, and GenX Chemicals: EPA is also proposing a regulation to limit any mixture containing one or more of PFNA, PFHxS, PFBS, and/or GenX Chemicals. For these PFAS, water systems would use a hazard index calculation, defined in the proposed rule, to determine if the combined levels of these PFAS pose a potential risk.

If finalized, the proposed regulation will require public water systems to monitor for these chemicals. It will also require systems to notify the public and reduce PFAS contamination if levels exceed the proposed regulatory standards. At the announcement EPA Administrator Michael S. Regan said “EPA’s proposal to establish a national standard for PFAS in drinking water is informed by the best available science, and would help provide states with the guidance they need to make decisions that best protect their communities. This action has the potential to prevent tens of thousands of PFAS-related illnesses and marks a major step toward safeguarding all our communities from these dangerous contaminants.”

There are thousands of PFAS chemicals, and they are found in many different consumer, commercial, and industrial products. This category of chemical has been widely used for over 80 years mainly for their ability to repel oil, grease, water, and heat. We are all exposed to PFAS in everyday life. Stain-resistant carpeting, nonstick cookware, grease- and water-proof food packaging, fabric softeners, waterproof clothing, cosmetics, and through our diet and water. These forever chemicals have remained in the soil, been taken up into plants, and made their way into animals who eat those plants. According to Fairfax Water diet is responsible for 66%-72% of exposures to PFOA and PFOS (the two chemicals that have been most widely studied). In some cases, they have also leached into both surface and groundwater. Water is responsible for 22%-25% of exposures.

In anticipation of future regulations, Fairfax Water hired an independent lab to test their water using current EPA-approved methods that can detect PFAS at much lower concentrations than previous methods. Fairfax Water also participated in the Virginia Department of Health (VDH) Occurrence Study that was completed in 2021. However, 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. PFAS dissolves in water, and combined with their chemical properties means that traditional drinking water treatment technologies used at water treatment plants are not designed to remove them, it is believed though, that carbon filtration does remove some. Activated carbon adsorption, ion exchange resins, and high-pressure membranes have been found to remove PFAS from drinking water, especially Perfluorooctanoic acid (PFOA) and Perfluorooctanesulfonic acid (PFOS), which have been the most studied of these chemicals.

Keeping PFAS out of the source water the 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 source of water and can mix them to minimize exposure or remove them. Source water protection will also have to be part of the solution. With that in mind both Fairfax Water and the EPA have developed an analytic framework which provides information about PFAS across the environment. This information will help them better understand potential PFAS sources in our communities and develop a road map to complying with the regulation if it is finalized and providing safe drinking water to Northern Virginia.

“At Fairfax Water, we know that drinking water is vital to public health,” stated Fairfax Water General Manager Jamie Hedges.  “We’ve taken a proactive approach to address PFAS through voluntary PFAS monitoring and educating the community on the importance of protecting the region’s source water from these compounds.  Stopping PFAS at the source, before it reaches drinking water sources, is key to ensuring our customers have high-quality water at affordable rates.”

Sunday, March 12, 2023

DEQ Amends its Data Center Diesel Generator Variance

After the Public hearing on February 27, 2023 in Woodbridge, the Virginia Department of Environmental Quality (DEQ) has decided to revise the proposed variance for data centers originally published on January 26, 2023, to restrict its application to emergency generators located at data centers in Loudoun County only, removing Prince William and Fairfax Counties from the proposed variance.

Data center operation relies on the use of large amounts of electricity from the grid. Due to the fast pace of growth in data centers in Northern Virginia Dominion Energy has not kept up with the surging demand for power. According to Dominion Energy, the transmission constraints will persist until at least 2025 and probably 2027. According to PJM the currently operating data centers could cause a cascade failure in the power grid during periods of high demand.

Maintaining an adequate level of generation resources, with the right operational and physical characteristics, is essential for PJM’s ability to serve electrical demand through the energy transition mandated by the Virginia Clean Economy Act of 2020. PJM anticipates that retirements of fossil fuel electricity generation are outpacing the construction of new electrical generation resources; and expects that the growth rate of electricity demand will continue to increase from electrification coupled with the proliferation of additional high-demand data centers in the region. The sheer size of the load needed for data centers and its flat profile throughout the day, require more name plate generation by variable sources in addition to  transmission capacity. So in their most recent report PJM indicated the electrical supply constriction may exist far beyond the period of the current variance, Spring 2023 and need to be renewed.

In the revised variance DEQ voices concern that Loudoun County is an area in which there may not be a sufficient amount of electricity available for data centers due to these severe, localized constraints in electricity transmission and demand. To prevent knocking out the entire region, in times of grid stress, they need for the data centers to power down. However, to keep operating, the data centers would need to step off the grid and use their generators. The data centers will be paid a bonus to step off the grid.

This proposed order and local variance would provide data centers located in Loudoun County a measure of relief from existing regulations and permit provisions that limit the use of Tier II and Tier IV emergency generators. Under the variance, data centers in Loudoun Count may operate their Tier II and Tier IV generators during periods that PJM has initiated a "Maximum Generation Emergency/Load Management Alert" or during periods that PJM has declared a "Post Contingency Local Load Relief Warning" for Loudoun County. According to the Washington Post: “Since 2020, three “Maximum Generation Emergency Load Alerts” have been issued — all of them last year, according to the PJM website.” The second category, “Post Contingency Local Load Relief Warnings” — are issued far more common, with 90 occurring in Dominion’s coverage area last year.  

DEQ estimates that there are approximately 4,021 diesel-fueled Tier II generators (older and of higher emissions) and 130 Tier IV (lower emissions) generators located at data centers in Loudoun County. The likely potential pollutants from a generator could include nitrogen oxides (NOX), particulate matter (PM10 and PM2.5), carbon monoxide (CO), volatile organic compounds (VOCs), and sulfur dioxide (SO2). The exact number and duration of events, if any, that may occur before the end of July 2023 when this variance ends cannot be predicted. However, by federal regulations limit the amount of nitrogen oxide emitted by permit holders to 100 tons per year and DEQ estimate the emission per hour per generator. With those restraints all the generators could run approximately 5.13 days this is the potential emissions in Ashburn for this variance.


The comment period has been extended through April 21, 2023. A new public hearing will be conducted in the Conference Room, Northern Regional Office, 13901 Crown Court, Woodbridge VA, at 11:00 a.m., on Thursday, April 6, 2023 the second day of Passover.


Wednesday, March 8, 2023

Even with the Rains the Colorado River is still in Trouble

Over one hundred years ago the Colorado Compact apportioned the water of the Colorado River amongst the seven compact states (Colorado, Utah, Wyoming, New Mexico, Arizona, California, Nevada) and Mexico. 1922 Colorado River Compact allotted the Colorado’s water on the basis of territory rather than prior appropriation. Before this agreement was negotiated ownership of water rights was based on historic use, first to use the water owned it in perpetuity.  California was growing so fast the other territories feared they would appropriate all the water preventing their territories from ever being able to grow. The allocation of water rights based on territory allowed development to proceed in the lower basin (essentially California at that time) while safeguarding supplies for the upper basin. Then, as now, California's growth and demand for water was viewed with concern by her neighbors. To this day California still has the most senior water rights; however, the historic allocation of water rights is being questioned due to the growing water crisis.

Lake Meade 2000-2022 from NASA

The amount of water allocated under the Colorado Compact was based on the belief that the river's average flow was 16.5 million acre feet per year. The upper Colorado River was allocated 7.5-million-acre feet to the upper basin (Colorado, Utah, Wyoming, New Mexico), the lower basin Colorado River (Arizona, California and Nevada) were allotted 7.5-million-acre feet and Mexico was allotted 1.5-million-acre feet.

From the start there was a problem; they over allocated the Colorado River.  According to the University of Arizona, a better estimate would have been 13.2-million-acre feet at the time of the Colorado Compact.  Once the flow of the Colorado exceeded needs, but this is no longer true. Use of the river has increased tremendously over the last century. While over the same period of time, the flow from the Colorado River has fallen attributed to changing land use and changing climate. From 2000 through 2022, the river's annual flow averaged just over 12 million acre-feet; and in each of the past three years, the total flow was less than 10-million-acre feet.

The records going back to Paleolithic times (more than 10,000 years ago) indicates the region is subject to periods of mega-droughts in the distant past and climate forecasts for the future are dire. There has been a drought somewhere in the Colorado River Basin for the past 22 years. This combined with higher temperatures has led to what some are calling aridification of the region. The Colorado River and its watershed are in trouble, the states need to work together to come up with a sustainable use plan for the future.  

Population growth, increased food production and increased power production all consume more and more water. The water available from the Colorado River has decreased, not increased with the increased demand. Even without climate change more than 35 million people (in the upper and lower basins) now depend upon the Colorado River’s waters for their water supply. The need for water is always growing with population and wealth. Currently in the upper basin, 44% of Wyoming, 37% of Colorado, 89% of Utah, and 45% of New Mexico are in drought. In the lower basin 13% of Arizona, 83% of Nevada and 49% of California are in drought. This is actually is much improved over the summer. 

from the Lake Meade water database

California is the most populous state in the nation and Nevada is one of the fastest-growing states in the nation and their need for water has continued to grow. Despite aggressive conservation activities the region simply does not have enough water to meet the projected demand. Las Vegas was able to reduce water use by a third by the implementation of draconian conservation measures (removal of ornamental turf grass and utilization of low flow plumbing fixtures etc.). This was city and suburban consumption, not agricultural or power generation use of water which is much more difficult to cut and utilizes the largest share of water. Remember though, that agriculture use of water is to feed the growing number of people. Hydropower, is a significant source of power to the region.

Lake Meade sits on the Nevada-Arizona border and was created in 1935 by the construction of Hoover Dam. Lake Mead and the upstream Lake Powell are the major water storage facilities in the Colorado Compact system. Roughly 96% of Lake Mead's water comes from melted snow in the upper Colorado River basin states.  The Compact states have not delt with the fact that the allotted water in the basin exceeds the average long-term (1906 through 2018) historical natural flow by a considerable amount. To date, the imbalance has been managed by slowly using up the considerable amount of reservoir storage capacity in the Colorado River system- Lake Powell and Lake Mead once held approximately 60 million acre-feet.

When built, it was assumed that drought years would be followed by wet year to refill the reservoirs. That has not happened recently, the last time the reservoirs filled was 1983. Instead, the reservoirs have been used to hide the fact that use of water exceeds average river flow and delay finding a long term sustainable solution. This cannot continue. The reservoirs (Lake Meade and Lake Powell) have dwindled to their lowest levels recorded and are nearing dead pool state when water can no longer be drawn out. Dead pool levels mean the dam can no longer release water downstream or generate power. 

The true existential crisis for the areas that depend on the water from the Colorado River looms just over the horizon. For without water there is no life. The states of the Colorado Compact need more water. Overuse is killing the Colorado water basin which suffers from decimated aquatic ecosystems, overdrawn and irreparably damaged groundwater aquifers, and polluted agricultural and urban runoff.

Water releases down river from Lake Meade and Lake Powell reservoirs are determined by the Bureau of Reclamation. Each year they forecast reservoir water elevations. Plans that were developed over the past two decades lay out detailed operational rules for these Colorado River reservoirs. The Bureau of Reclamation asked the states to voluntarily cut usage by 2 to 4 million acre-feet in response to the ongoing drought and historically low water levels in Lake Mead and Lake Powell reservoirs. 

However, the cuts in water usage proposed by the states are nowhere near enough to stop the falling water levels in the reservoirs. California’s water rights are considered senior and California interprets the law to mean Arizona should cut its supply before California. The Upper Basin states have said the Lower Basin states should receive the most cuts. All are afraid that emergency cuts will become permanent.

Last July drought operations were implemented to protect Lake Powell and the Bureau of Reclamation Since the states could not do it the Bureau of Reclamation is set to release a proposal on how to operate the Lake Powell and Lake Mead reservoirs and their adjacent dams (Glen Canyon and Hoover) in March, with the goal of finalizing it by mid-August.  Right now, they are in a stalemate until the water is rationed to overcome the political hurdles to renegotiate the Colorado Compact. California won’t give up its senior water rights and Colorado is attempting to dam tributaries to the Colorado River to hold all water they can in Colorado. It will have to reach complete crisis level before the states are ready to renegotiate the Colorado Compact and the winter rains and snow have rescued the situation for now.   

Monday, March 6, 2023

The First River Cleanup of the Season


from MF Master Naturalists

A sure sign that Spring is in the air is the arrival of river cleanup season. On March 11th 2023  The Bull Run Watershed Protectors will hold the first river cleanup of the season in Manassas cleaning the stream valley behind Costco, across Lomond to Ashton Rd. and the shops/restaurants adjacent down to Walgreens at Sudley Manor Road.

The community, Honor Societies, Scout troops and ROTC’s have helped to remove over 12,000 lbs. of trash since 2018 from the stream valley.  The result has been the return of frogs, toads and salamanders.  Which are indicator species for clean water.  

Unfortunately, it is necessary to hold these river cleanups annually. Year after year volunteers clean our roadways, streams, rivers, and streambeds of trash that started as litter and carried along by stormwater and wind into our waterways and parks. We also remove items that were illegally dumped or carried by off by storms. Don’t litter and teach your children not to litter, that is the best way to prevent trash along our roads, streams and waterways. Bring the kids out to help cleanup the trash dropped or thrown on the ground. It does not magically disappear, but finds its way carried by stormwater to our waterways and parklands disrupting the natural water flow and beauty of our natural world. Come out and help us make our water ways free of trash.

The Bull Run Watershed Protectors are the Merrimac Farm Master Naturalists, Friends of the Square, Prince William Soil and Water Conservation District, Keep Prince William Beautiful, Prince William County Watershed Division and Environmental Services. They will provide safety vests, gloves, grabbers and bags. Pleas join in this worthwhile endeavor! Online sign up is at this link.

Rain date: Saturday, March 18th, same time and place

Wednesday, March 1, 2023

Watersheds and Land Use

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, Chicago, San Francisco, Los Angeles and  hundreds more across the nation confined and subsumed many thousands of streams, erasing them from public memory.

In a study done early this century they found that Philadelphia had buried 73% of its streams. Another study counted 66% buried in Baltimore. Many streams that remained on the surface were sick or dying. A stream is a living ecosystem. It includes not just the water coursing between the banks but the earth, life and water around and under it. Beneath a living streambed is a layer of wet sediment, small stones and tiny living creatures called the hyporheic zone. Stream water filters down into this dynamic layer between surface water and groundwater, mixing with the groundwater pushing up to feed the rivers during dry spells. Water in the hyporheic zone flows downstream like the surface water above it but much, much more slowly.

For a large river the hyporheic zone is the essential engine of life. This zone can be tens of feet deep and can extend up to a mile laterally beyond the banks. It keeps the waterway healthy by regulating critical physical, biological and chemical processes, including riverbed aeration, water oxygenation, temperature moderation, pollution cleanup and food creation. Developing this lateral zone slowly begins the destruction of the watershed.

Cutting down streamside vegetation and woodland buffers that once slowed and absorbed rains causes floods. These floods were only made worse by covering the ground with compacted and/or impervious surfaces.  The faster flow of storm water gouged the riverbed. Later, urban planners and engineers funneled streams into buried pipes so they could build more city on top, disconnecting waterways from soil, plants and animals. The cumulative impact of these injuries led to flash floods, unstable banks, heavy pollution and waning life. 

In general, streams in urbanized areas are likely to have higher levels of oxygen demand, nutrients, suspended solids, ammonium, hydrocarbons, and metals. The negative impacts of urban land use on adjacent reservoirs, streams, and rivers have been well-documented in the literature. To establish effective water quality management policies, it is essential to understand the true nature of the relationship between water quality and urban land use.

Scientists have found that land use management can enhance or destroy stream water quality.  Particularly they found in a recent study when urban land use is in the range of 1.1%–31.5% of a watershed a watershed can still be restored. If urban land use exceeds 31.5% in a watershed water quality does not respond to restoration measures as expected. Once you destroy a watershed we do not know how to restore it.

Although close relationships between the water quality of streams and the types of land use within their watersheds have been well-documented, many aspects of these relationships remain unclear. Recent studies have suggested that the relationship is not linear which is commonly used in current land use models. Many of our remaining watersheds today are degraded characterized by degraded forests, invasive plants, soil erosion, erratic streamflow, declining groundwater resource, loss of biodiversity, microclimate deterioration, and declining ability to store water.

Prince William county is promoting regressive land use policies and practices, those from the last century when we did not recognize that all water is connected and the health of the watershed determines the quantity and quality of water resources. The hyporheic zone is an integral part of our freshwater ecosystems.  The hyporheic zone is made up of sediments, but is porous enough to allow the exchange of nutrients, dissolved oxygen, and water and serves to keep our streams healthy.  Water doesn’t just flow through the hyporheic zone, but has a specific residence time. This allows pollutants and nutrients to be removed, protecting water quality. During drought, flooding, and temperature extremes, the hyporheic zone becomes a refuge for many species. Let us hope that Prince William County can correct course before the Occoquan watershed is degraded beyond redemption. 

Sunday, February 26, 2023

Data Centers their CO2 and Water Footprint

Data centers are the bricks and mortar of the internet. These buildings store servers, digital storage equipment, and network infrastructure for the large-scale data processing and storage.  Our increasingly digital world has an ever-growing need for data creation, processing, and storage from businesses, online platforms, video streaming, smart and connected infrastructure, autonomous and driver assist vehicles, and artificial intelligence. The amount of data created and stored globally is expected to reach 175 Zettabytes by 2025, representing nearly a six-fold increase from 2018. The role of data centers in storing, managing, and distributing data has remained largely out of. Similarly, the environmental implications of data centers have been obscured from public view. 

The United States houses nearly 30% of data center servers, more than any other country; and northern Virginia houses more data centers than any other locality. In a study recently published in Environmental Research Letters, Landon Marston, an assistant professor at Virginia Tech and colleagues looked at how and where data centers consume energy and water in the United States. The results showed that it takes a large amount of water to support the internet and cloud service and that the water often comes from water-stressed basins. Physical location of data centers impacts the carbon and water footprint.  Below are excerpts from their study “The environmental footprint of data centers in the United States”

Citation Md Abu Bakar Siddik et al 2021 Environ.Res. Lett. 16 064017DOI 10.1088/1748-9326/abfba1

Though the amount of data center computing workloads has increased nearly 550% between 2010 and 2018, data center electricity consumption has only risen by 6% in that time due to dramatic improvements in energy efficiency and storage-drive density across the industry. However, the water and greenhouse gas footprint of the data center industry is huge. In addition, it is unclear whether energy efficiency improvements can continue to offset the energy demand of data centers as the industry is expected to continue its rapid expansion over the next decade.

In this study, Drs Marston et al used the records of data center operations to provide the first regional estimates of data center water and carbon footprints. The water footprint is defined as the consumptive blue water use (i.e. surface water and groundwater). The greenhouse gas footprint of a data center, expressed as equivalent CO2, is used to represent its global warming potential. The scientists looked at the operational environmental footprint of data centers which includes the power plants, water supplier, and wastewater treatment plant servicing the data centers. 

Power plant-specific electricity generation and water consumption data come from the US Energy Information Administration (EIA). The U.S. Environmental Protection Agency's eGRID database provided GHG emissions associated with each power plant.

The indirect water and carbon footprint of each data center consists of water consumption or GHG emissions associated with the generation of (i) electricity utilized during data center operation, (ii) electricity used by water treatment plants for treatment and supply of cooling water to data centers, and (iii) electricity used by wastewater treatment plants to treat the wastewater generated by a data center. 

Direct water consumption of a data center is based on heat generation related to the amount of electricity used. Estimates of data center specific electricity demand were multiplied by the typical water cooling requirement—1.8 m3 per MWh—to estimate the direct water footprint of each data center. Data center wastewater is largely comprised of blowdown; the portion of cooling water removed from circulation and replaced with freshwater to prevent excessive concentration of undesirable components. In general data centers recycle their water until the concentration of dissolved solids (which is essentially salts) is roughly five times the supplied water. 

Since water stress is expected to increase in many watersheds due to increases in water demands and more intense, prolonged droughts due to climate change. For these reasons, environmental considerations may warrant attention alongside typical infrastructure, regulatory, workforce, customer/client proximity, economic, and tax considerations when locating new data centers. However, placing all new data centers within a small area may strain local energy and water infrastructure due to their collective water and energy demands. The scientists suggest that data centers can be dispersed more broadly in areas that are favorable with respect to water footprint, water scarcity, or carbon footprint. As seen in the diagram below shows that seems to indicate that parts of the northeast and southern Florida are the best locations for data centers to minimize GHG and water impacts.

from Marston et al

The scientists also suggest the data center industry can make investments in solar and wind energy. Directly connecting data center facilities to wind and solar energy sources ensures that water and carbon footprints are minimized. However, data centers require level power supply and renewable sources are variable. Purchasing renewable energy certificates from electricity providers does not necessarily reduce the water or carbon footprints of a data center. However, these investments gradually shift the electrical grid toward more renewable energy sources, lowering the overall GHG impact for all energy users. 

Overall, the scientists show that strategically locating new data centers can significantly reduce their environmental footprint. Climatic factors can make some areas more favorable due to lower ambient temperatures, thereby reducing cooling requirements. Lower cooling requirements reduces both direct and indirect water consumption, as well as GHG emissions, associated with data center operation. Since most data centers meet their electricity demands from the grid, the composition of power plants supplying electricity to a data center plays a significant role in a data center's environmental footprint. The scientist show that real estate decisions may be as important as technological advances in reducing the environmental footprint of data centers.

Read the entire article here.

Wednesday, February 22, 2023

CA Again Saved by the Rains

In January this year the rain and snow have returned to California. Powerful storms brought snow in the Sierras, rain and flooding; but the atmospheric river saved California from running out of water. Only about 15% of California remains in drought and the reservoirs are fuller, but impact to groundwater from the drought and rains is still being tallied by the NASA GRACE follow-on project and will not be available for a month or two.

The dual-satellite GRACE Follow-On mission, a partnership between NASA and the German Research Centre for Geosciences (GFZ), is a successor to the GRACE satellites that ceased operations in 2017 after fifteen years of service. GRACE maps Earth's gravity field by making accurate measurements of the distance between the two satellites, using GPS and a microwave ranging system. This allows scientists all over the world an efficient and accurate way to map Earth's gravity field.

The GRACE mission is able to monitor monthly water storage changes on the planet. Regardless of whether water is solid, liquid or vapor, visible or invisible, it has mass, which exerts a gravitational pull. By tracking the changing pull of gravity very precisely around Earth, the U.S./German Gravity Recovery and Climate Experiment, or GRACE, mission observed the movement of water around our planet from 2002 to 2017 -- from the top of the Himalayas to the depths of the ocean to deep underground. GRACE Follow-On continues that work. In the meantime we know that groundwater in the central valley reached a historic low in November.

California experiences the most extreme variability in yearly precipitation in the nation. The potential for wide swings in precipitation from one year to the next requires that California must be prepared for either floods or drought in any year and has extensive water infrastructure-aqueducts, bridges, dams and more.

California uses about 37 million acre feet of water a year, 26 million acre feet for agriculture and 9 acre feet for all other users. An acre foot is about 326,000 gallons. In non-drought years 30-40% of the water is supplied by groundwater. However, in a drought California draws more than 60% of its water from groundwater. This is more groundwater than can be naturally recharged.

The groundwater of the southern Central Valley of California has both an upper unconfined and deeper confined aquifer system. An unconfined, or water -table aquifer is an aquifer whose upper surface is the water table under atmospheric pressure. The water table rises and falls with moisture content that is contained in the soil, and water can be extracted or recharged easily with only seasonal compaction and rebound of the land in wet years.

However, water-table aquifers are usually shallower than confined aquifers and because they are shallow, they are impacted by drought conditions much sooner than confined aquifers. Thus, most water wells draw from the deeper confined aquifers. The water is drawn from the fine-grained confining layers called aquitards. Water enters these aquitards very slowly and the danger is that the compaction of the layers will become permanent. If the water levels are drawn too low, then an irreversible compaction of the fined-grained confining layer occurs and there is permanent subsidence, permanently reducing the storage capacity of underground aquifers, threatening future water supplies; and also lowering the level of the land surface.

Subsidence caused by groundwater pumping in the Central Valley has been a problem in California for decades. Subsidence is also a serious problem for California's water managers, and their infrastructure. The subsidence puts the state and federal aqueducts, levees, bridges and roads at risk of damage. In the past few years subsidence has damaged thousands of public and private groundwater wells throughout the San Joaquin Valley. In recent years California has begun to try and manage their groundwater realizing it is a limited resource. It just may be a little late in the game.


Monday, February 20, 2023

No More Secrets

The data center companies are highly secretive about the data centers that power the internet. There are some valid reasons, but the cloud companies operating in our region have used secrecy to hide their activities from their neighbors, cut deals in secret and sidestep public concerns. Now that secrecy could create a public health disaster. According to the Washington Post, there are 275 data centers in Northern Virginia and over 70% of the internet traffic goes through our communities. 

Now the data centers and northern Virginia have a problem.  Dominion Energy lacks sufficient transmission capacity to consistently power data centers, and during times of high power demand if the data centers do not shut down, they could bring down the grid. When the PJM load forecast was updated last summer, PJM identified the need for additional 230 kV transmission segments to serve data centers in our area (Loudoun, Prince William and Fairfax). The sheer size of the load and its flat profile throughout the day, require more transmission capacity. There is no work around. Dominion needs to run more 230 kV transmission wire to avoid the potential of a cascading failure. Unfortunately, that takes time.

Though Dominion Energy has made significant investments in new infrastructure, it has not kept up with the surging growth of data center demand for power. According to Dominion Energy, the transmission constraints will persist until at least 2025. According to PJM the currently operating data centers could cause a cascade failure in the power grid. To prevent knocking out the entire region, in times of grid stress, they need for the data centers to power down. However, if you turn off the data centers, you turn off the internet.

As a short term solution the Virginia Department of Environmental Quality (DEQ) is proposing to allow data centers located in the Counties of Fairfax, Loudoun, and Prince William to operate using their emergency generators when a "Maximum Generation Emergency/Load Management Alert" or a "Post Contingency Local Load Relief Warning" is given by PJM.  That would authorize the data centers' on-site generators to operate when transmission constraints and strain on the electric grid are acute, and allow the data centers to avoid shutting down and to continue to serve their customers, maintain the integrity of internet, and alleviate demand on the electric grid during periods of stress. The current variance is for March through July 2023, but would have to be renewed annually (or seasonally) through at least 2025.

There is a cost. When the generators fire up there will be thousands of industrial sized diesel generators of various ages operating simultaneously during a period of high electricity demand, probably a heat wave. These will be stationary sources of pollution in a limited area operating on the ground level. It is essential that we avoid creating a public health emergency in our communities along with a power emergency.

The emission standards for newly manufactured diesel generators were tightened from 2008 through 2015 under Clean Air Non-Road Diesel Rule of 2004. The dates of manufacture of the  generators deployed all over northern Virginia is not known.  In addition, there has never been a planned operation of thousands upon thousands of stationary diesel generators in such a small geographic location before. According to CARB diesel engines emit a mixture of air pollutants. The solid material in diesel exhaust is known as diesel particulate matter (DPM). DPM is a subset of particulate matter less than 2.5 microns in diameter (PM2.5) and is the particulate matter air pollution most associated with adverse acute and long term health effects. These health effects include cardiovascular and respiratory hospitalizations, and premature death.

Health effects can result from both acute and long-term exposure to particulate pollution. People most sensitive to particulate pollution include infants and children, the elderly, and people with existing heart and lung disease. The smallest particles can penetrate deepest, causing the greatest harm. Particles created from combustion soot tend to be fine particles with diameters smaller than 1 microns  which are the most dangerous because they lodge in the lungs.

According to the EPA: "The health effects of particle pollution exposure can range from relatively minor (e.g., eye and respiratory tract irritation) to more serious health effects (e.g., exacerbation of asthma and heart failure, and premature death). Fine particles are respiratory irritants, and exposures to high concentrations can cause persistent coughing, phlegm, wheezing, and difficulty breathing.  Even in healthy people, exposures to fine particles can potentially lead to transient reductions in lung function, and pulmonary inflammation.”

To protect the residents of Loudoun, Fairfax and Prince William it is essential that when the data centers are going to switch to diesel power that the public is notified of the forthcoming air quality emergency. This would allow the population to take sensible steps like avoiding outdoor activities and sports to protect themselves and their children farm harm. Notification would allow the most vulnerable individuals in our community to take protective measures by staying indoors, using air purifiers, wearing masks etc. could prevent acute health emergencies. In addition, the data center companies need install air monitors around their properties that would be available to publicly view the air quality in real time so that regulators, health organizations and others can know what they are dealing with.

Like it or not, data centers are part of our community and the time for the excessive secrecy, non-disclosure and other “trade secret” BS has passed. It is apparent, that DEQ and the Commonwealth will allow data centers to operate on their generators. It is obvious that DEQ has forgotten that the point of the regulations is to protect people and the environment, not serve industry. They need to help us to protect ourselves, our children and the most vulnerable in our counties by requiring community notification and real time air quality monitoring. Come to the Public hearing on February 27, 2023 at 11 am in the Conference Room, DEQ Northern Regional Office, 13901 Crown Court, Woodbridge VA. 

Thursday, February 16, 2023

RPA and Forest Restoration Project – year 4

My house sits on a bit over 10 acres, about three of them lawn and ornamental gardens. The remaining seven acres is woodland, and much of the woodland is part of the “resource protected area,” RPA. Until a few years ago I felt we did not have to worry about dead trees, as it was all part of the natural process of renewal.

A healthy forest has living trees functioning as part of a balanced and self replacing ecosystem that is a complex mix of trees, understory shrubs and groundcover. In a healthy woodland the process of natural succession occurs over time. Small saplings develop and will become the next generation of trees as the older ones die out. Benign neglect had been my rule for managing the RPA.  

RPA’s as defined in the Chesapeake Bay Preservation Act are vegetated areas along water bodies, such as lakes, streams, rivers, marshes or shoreline. RPAs are the last line of defense for the protection of water quality. These buffers stabilize shorelines and stream banks, filter pollutants, reduce the volume of stormwater runoff and provide critical habitat for aquatic species and wildlife. Trees and shrubs in riparian buffers reduce erosion, improve air quality, and provide shade in the summer, windbreaks in the winter.

However, about 5 years ago the number of dead and dying trees had increased dramatically due to the emerald ash borer and it became obvious that the invasive vines, autumn olive and Japanese honeysuckle were choking out the natural renewal process. So, with guidance from the Forest Service and the Chesapeake Bay Act guidelines I began a project to restore  

Kinner Ingram, who at the time was an Urban and Community Forestry Specialist from the Virginia Department of Forestry came out and inspected the woodland and made some recommendations.  He felt that with removal of the invasive vines and the hanging dead trees the wood might begin to renew itself. He put his recommendations in a report for me to submit to Clay Morris, Natural Resources Section Chief, Environmental Services Division of Prince William County Public Works. Though the RPA covers just 2/3 of the woodland, I am treating all the wooded area in the same way. I was strictly by the book in what is allowed in an RPA as outlined in the PW County literature. 

We are now in the forth winter of my RPA and forest restoration process. It is slow work, but we are making progress. I use we very loosely, Wetland Studies and Solutions is doing all of the actual labor. Here are a few pictures of how it's looking. 

Here is were we ended this year:

Here is the summertime goal

Sunday, February 12, 2023

Tackling Invasives

 Over the weekend there was a Native Plants Seminar at George Mason University in Manassas. I've attended the seminar in years past and used what I learned to inspire me to make improvements in my own yard. I attended this year via zoom to get ideas for my woodland restoration and garden re-plantings. I was indeed inspired. 

The two pictures below are of the same section of my yard taken a year apart. For years this first picture was the view of the side yard, but quite frankly, I just did not really know how to begin to make improvements. Finally with encouragement from an Urban Forester a plan was made. The simple truth is that you begin with heavy duty cloths, boots, gloves, a hedge clipper and chain saw. 

Last winter Wetland Studies and Solutions began tackling the invasive grape, autumn olive, Japanese Honeysuckle and goodness knows what else was in there (we found a tire and plastic containers). They made great progress last year, but this winter's work has totally transformed the area. Totally worth the money I spent on young and strong foresters to do what I simply can not do. I am really good at collecting trash and litter.

The the picture was taken by Wetland Studies and Solutions before they started on the removal of the invasive plants in this section last winter. Two people worked for a couple of days last February cutting away invasive species and building habitat piles before the money I had allocated in my not to exceed contract ran out. Then they returned this February to finish up this section after I had saved up more money and opened another contract. What a difference. 

I will not lie, this is expensive work, so we do a little each year. The same view a year apart (though, two seasons of spending) makes me feel like it is worth it. Now to "beautify" the side yard a bit I plan to introduce the beginnings of a shrub layer and make a second attempt at wildflowers. I tried sowing a wildflower mix last year, but did not have much success. 

A healthy forest has five layers: an overstory, and understory, a scrub layer, an herbaceous layer, and leaf litter. As best as I can tell in February, many of the cedars in the wood, seem to be a dead, but the other trees are not. There does not seem to be much of a scrub layer, the invasive autumn olive seems to have out competed them. I have had some great success on the other side with planting ninebark after clearing out Japanese honeysuckle, so I may give them a try here. They seem particularly hardy and the birds love them for nests.

Thursday, February 9, 2023

Data Centers to be Allowed to Run on their Diesel Generators More Often

There will be a public hearing on February 27, 2023 at 11:00 am at the DEQ offices in Woodbridge, VA. It will be in the Conference Room of the DEQ Northern Regional Office at:  13901 Crown Court, Woodbridge VA, at 11:00 a.m. The meeting is to discuss and hear comments on the proposal to allow datacenters in Northern Virginia to operate during times of constrained power on their thousands upon thousands of backup generators. The generators are stationary sources of air pollution equivalent to thousands of heavy duty diesel trucks running in our backyard. This could be a critical public health issue for many and should be treated as such. 

Loudoun County has courted data and cloud companies making development and land use decisions that has resulted in Loudoun County having the highest concentration of data centers in the world. These data centers provide a very significant amount of revenue to the county through real estate and business personal property taxes. In recent years, Prince William County has copied Loudoun County’s approach and approved many data centers. Data center growth in Prince William County has increased significantly and is poised to take off.  

However, data center operation relies on the use of large amounts of electricity from the grid. Dominion Energy has informed Loudoun County that it will not be able to provide power to new data center projects in Ashburn at this time. They lack  adequate transmission capacity and building it could delay new data centers coming online by a year or more. Virginia is concerned that the Counties of Fairfax, Loudoun, and Prince William may not have sufficient electricity for data centers in the next couple of years due to severe, localized constraints in electricity transmission.  Dominion has already informed the counties that a transmission constraint exists in the area which may affect the ability to provide enough electricity to data centers through 2025.  In particular, the period between March and July 2023 has been identified as a time of potentially acute stress on the transmission capacity of the grid.

Now, the VA Department of Environmental Quality (DEQ) has issued a notice of action that would authorize the data centers' on-site generators to operate during times that fall short of a PJM declared emergency but when transmission constraints and strain on the electric grid would be acute and thereby allow the data centers to continue to operate instead of shutting down to alleviate demand on the electric grid. While Dominion can buy electricity from the PJM members (Pennsylvania and West Virginia who generate electricity by natural gas and coal) there is simply inadequate transmission lines to meet all the demand in Loudoun, Prince William and Fairfax at this time. So, they are going to produce the needed electricity in the dirtiest way possible. 

According to the California Air Resources Board: “Standard gasoline and diesel generators emit a lot more pollutants and greenhouse gas than some other options…Diesel particulate matter (PM) emissions from an average industrial diesel generator (~800 hp), operating at an average load of ~300 kW for 1 hour, is equivalent to driving nearly 660 miles in an average heavy duty diesel truck.” Each data center has 250-300 diesel generators. What the DEQ is proposing is to have the equivalent of thousands of heavy duty diesel trucks running (not idling) in one spot in our counties for hours or possibly days.

Health effects can result from both short-term and long-term exposure to particulate pollution. People most sensitive to particulate pollution include infants and children, the elderly, and people with existing heart and lung disease. The smallest particles can penetrate deepest, causing the greatest harm. Particles created from combustion soot tend to be fine particles with diameters smaller than 2.5 microns (PM 2.5) which are the most dangerous because it lodges in the lungs.

The U.S. Environmental Protection Agency, EPA, requires states to monitor air pollution to assess air quality and ensure that they meet minimum air quality standards. The US EPA has established both annual and 24-hour PM2.5 air quality standards (as well as standards for other pollutants). The annual standard established in 2012 is 12 µg/m³ (an AQI of 39). The 24-hr standard remained at 35 µg/m³ (an AQI of 99). Exceeding the 24 hour standard could cause acute health impacts. In addition, there are other air quality rules that might come into play here specifically the Clean Air Non-Road Diesel Rule of 2004.

In 2020 electricity used in Virginia in 2020 was 30% more than the electricity used in 2010. The one growing sector of electricity demand in Virginia is data centers. In 2018 power demand for data centers was just over 1 gigawatt of power, by 2022 that had reached 2 gigawatt of power and is projected to reach 3 gigawatts by 2025 with projects already under way. The current power usage by data centers is more than to the power usage of 1.5 million houses which is almost half of all Virginia households. 

Virginia is the data center capital of the  world resulting in electricity use growing faster here than other states. Now the DEQ is proposing to turn us at least sporadically into the air pollution capital. Governor Youngkin has just trumpeted and praised the announcement from Amazon that they plan to invest $35 billion in data centers in Virginia. The largest private investment in the state’s history. With that investment Amazon will take control of the grid without any planning and has apparently also captured the VA DEQ. What the DEQ is proposing is to have the equivalent of thousands of heavy duty diesel trucks idling in one spot in our counties for hours or possibly days. 

The DEQ proposal only asks the Data Center operators notify the DEQ within three hours when they are operating their emergency generators  and to calculate the air pollution emitted by those generators during those times after the fact. The pollution should and must be measured in real time and  at the very least available for public viewing as all air monitors are; and the public notified immediately when pollution exceeds regulatory standards of an air quality emergency so that they can limit their exposure. Power shortages are only likely to happen on the hottest or coldest days. Summer heat waves are some of the worst air quality days and will only be made worse by the thousands upon thousands of diesel generators running in our backyard.

DEQ Notice of action: The Department of Environmental Quality (DEQ) is considering the issuance of an order and local variance for data centers located in the Counties of Fairfax, Loudoun, and Prince William.  A variance is an exception to a general rule. This notice is given in accordance with the requirements of § 10.1-1307 C of the Code of Virginia. 

Regulations affected: The primary regulation affected by this action is 9VAC5-80-1110 C of 9VAC5-80 (Permits for Stationary Sources). 

Purpose of notice: DEQ is seeking comments on the proposed variance. 

Public comment period: January 26 to March 14, 2023 at this link

Public hearing: Conference Room, Northern Regional Office, 13901 Crown Court, Woodbridge VA, at 11:00 a.m., on February 27, 2023.