Wednesday, April 27, 2022

Prince William the NRCS Team Winner for 2021

The National resource Conservation Service (NRCS) has awarded our very own Prince William Soil and Water Conservation District's Water Quality Team the National Group Volunteer Award for 2021.  This award recognizes one outstanding Group nationally.  The award is presented to the most effective Earth Team in a conservation district.

Despite the challenges presented by the pandemic you cannot stop such enthusiastic volunteers. The Prince William Water Quality program was started in 2015 by Veronica Tangiri who continues to spearhead the four areas of the program today. The Water Quality program consists of four areas of effort that are designed to promote public awareness and natural resource protection:

  • Adopt a stream, pond or river
  • Chemical Water Quality Monitoring
  • River cleanups
  • Floatable Monitoring

In 2021 PW had 124 volunteers who provide over 300 hours to support the Chemical Monitoring programs. Also, during 2021 over 1,600 volunteers removed over 35,000 pounds of trash from the rivers and streams in the county- saving the county more than $140,000 it would have cost to hire staff to do the work.

The Water Quality Team does an amazing job protecting the natural resources of Prince William and making our community more sustainable. Congratulations to the Water Quality Team!!!


Sunday, April 24, 2022

Earth Day Thoughts

Last Friday, April 22nd was Earth Day. Since its founding in 1970 Earth Day has evolved into an opportunity to spend a few hours outside with others cleaning up the trash from our water ways and road ways, planting trees and nature walks in our many regional parks to appreciate the trees.

Trees are what I want to talk about. The trees act as natural pollution filters. Their canopies, trunks, roots, and associated soil filter polluted sediment from the runoff to our streams and creeks and ultimately to the Chesapeake Bay. Trees also use and recycle nitrogen and phosphorus which contribute to the decay of our Occoquan Watershed, the Potomac and the Chesapeake Bay and its estuary. Trees protect our watersheds and drinking water supply.

Once a tree reaches maturity, it sequesters 48 pounds of carbon dioxide per tree per year. Planting trees is one of the biggest and cheapest ways of taking CO2 out of the atmosphere to tackle the climate crisis. Not only do forests act as carbon sinks, but they also provide vital habitat for animals and ecological services for humans, such as purifying the air we breathe and regulating local temperatures.

Yet, as we look across Prince William County our tree stands and forested areas are being choked out by the effects of the emerald ash borer and invasive species. In addition, we continue to intentionally remove old growth trees to make way for highly developed land and low-density residential and now solar panels. (I would like to see the carbon impact analysis for removing forest to plant solar panels.)

Forest ecosystems are the largest terrestrial carbon sink on Earth, and their management has been recognized as a cost-effective strategy for mitigating greenhouse gas emissions, yet we have ignored planning and supporting the forested tree system in Prince William County. Nationally and locally several initiatives have been proposed to mitigate forest loss and climate change through tree planting as well as maintaining and restoring forest ecosystems. These initiatives been inspired by global assessments of tree and forest attributes and their contributions to offset carbon dioxide (CO2) emissions. 

Our neighbor, Loudoun County has funded a Reforestation program targeted at planting trees to permanently reforest currently non-wooded land in multi acre residential plots and community areas in HOAs. A proposal for a similar program failed to be incorporated into any version of the budget for Prince William County despite support from staff in Environmental Services Division. We would all benefit from tree planting and reforestation.  A well conceived planting program would bring improved water quality and quantity (both surface and groundwater), reduced soil erosion, increased wildlife habitat, shade, and of course the beauty of the trees themselves.

"In the United States, forestland represents nearly one-third of total land area and forests store more than three decades of carbon dioxide (CO2) emitted from economy-wide fossil fuels."

Wednesday, April 20, 2022

Maintaining My Well- Keeping Iron Bacteria at bay

Iron bacteria, while not a health hazard, are an incredibly common nuisance in water wells, and once you have it you will always have it. Iron bacteria use dissolved iron in the water as an energy source and leave slimy deposits of red iron hydrate as a by-product. I test my well water each year during the annual water clinic the Prince William Extension Office hosts and every few years for all primary and secondary pollutants under the safe drinking water act but, iron bacteria is not part of those suite of tests. The standard bacteria tests test for coliform and fecal bacteria and do not test for iron bacteria. However, about a decade ago I tested my well water for iron/reducing bacteria and found a significant level. There had appeared a number of symptoms that suggested its presence, so I looked.

Iron bacteria once introduced into the well will not get better. Instead continue to get worse ultimately binding up your pump and fouling the well. Iron bacteria can grow on pump intakes and screens openings causing plugging reducing the yield and efficiency of the well. In addition, the bacteria will make the water smell and taste vaguely unpleasant. A much earlier symptom is slime build up on the toilet tank flipper and in my case gross foam in the ATU tank.

Elevated levels of iron, manganese and sulfate in groundwater are an ideal media for iron bacteria to grow. Iron bacteria are present in soils and surface water in this area of Virginia and in many other parts of the country. Iron bacteria can be introduced into a well during drilling or repair. There are tests that can look for these micro-biologicals. National Testing Laboratories sells a mail in test for $69 plus shipping if you want to test your well. That is what I used.

It is common practice to regularly treat public supply wells to prevent biofilm buildup and mineral encrustation. Preventive maintenance is to chemically treat and flush the production well.  However, this has not been the practice in private water well, though now several state health departments and Canadian Provinces are recommending the regular chlorination of private wells to push back the iron bacteria.

The last time I heard Brad White a groundwater geologist from the Virginia Department of Environmental Quality Office of Ground Water Characterization give a talk on the work DEQ was doing in Fauquier County, he happened to mention that in every well he put a camera down he had observed iron bacteria.

From Penn State Extension: “As a water well ages, the rate at which water may be pumped tends to decrease.” Penn State attributes this decrease in performance of a well to incrustations and biofouling (with reducing bacteria) of well screens and rock fractures or borehole, saying: “In severe cases, the obstruction to flowing water can render the well useless. Major forms of incrustations can occur from build-up of calcium and magnesium salts, iron and manganese compounds, or plugging caused by slime producing iron bacteria or other similar organisms (bio-fouling).”

The Provincial Government of Alberta (Canada) says in describing iron bacteria: “This slime will coat the inside of the well casing, water piping and equipment, creating problems such as reduced well yield, restricted water flow and red staining of plumbing fixtures and laundry...” There are all sorts of odd problems that are caused by iron bacteria. Over time many wells develop these problems. These harmless bacteria can foul a well, damage pumps, stain plumbing fixtures, clog pipes, faucets, showerheads, and produce unpleasant tastes and odors in drinking water. Rarely is well water tested for iron bacteria. 

Private well owners typically try to treat the symptoms rather than the cause of the problem. Elimination of iron bacteria once a well is heavily infested can be difficult. Iron bacteria cannot be eliminated by most common water filtration methods or water softeners. Iron bacteria will foul that equipment.  However, though it is difficult to eliminate, it is actually very easy to control – just oxidize the heck out of the well. This is accomplished by chlorine shocking of the well with adequate chlorine concentration and several hours of mixing accomplished by recirculation.  

As recommended by Alberta, Pennsylvania and other states,  routine maintenance of a private water well should include regular chlorination to control biofouling of the well and maintain water quality. Personally, I chlorinate my own well on even number years (yes that includes this year) to prevent the buildup of a biofilm in my well and plumbing system and maintain the aesthetic quality of my water. I drain and flush the hot water heater annually to protect it from biofilm and mineral buildup and keep the temperature above 145 degrees to prevent the growth of reducing bacteria.  If you have treatment equipment like a water softener, you might want to consider chlorinating your well annually and treating your media to prevent a bio mat from forming in the media tanks.

There are so many things that regular chlorination will solve or prevent that you might want to consider it a regular part of home maintenance. Even if you do not chlorinate your well regularly, you should chlorinate your well when:

  • the well is new
  • the well has been repaired
  • the well has been flooded
  • the well exposed to bacterial contamination in another manner, such as a crack in the well cap  

In addition, you should test your well at a minimum for coliform bacteria each year, usually in the spring (or the wet season), and if there is any change in the taste, color or odor of your drinking water. A confirmed positive test for coliform bacteria requires disinfection at the least. I will not chlorinate my well until after I review the results of my recent well testing. The approach I would take to disinfect the well and plumbing systems is a little more involved (and inconvenient) than what I would do for iron bacteria alone.

Sunday, April 17, 2022

More Steps Needed to Protect our Watershed from Salt

The Potomac River and Occoquan Reservoir are becoming saltier and this is a problem for the drinking water supply of Northern Virginia. Analyses from three different studies at multiple locations have found increasing freshwater salinization in Northern Virginia and the Occoquan Reservoir. Regionally, as salt levels have risen, WSSC is seeing discolored water problems related to winter deicing when chloride levels were observed to spike from 40mg/L to 100 mg/L. Increasing chloride levels is from rising sea levels, increased direct and indirect potable reuse of wastewater, the increased amount of pavement and the salting of roads in the winter. Nearly all road salt is eventually washed into adjacent rivers, streams, and groundwater aquifers - road salt is considered the largest contributor to rising salt levels.  

Road salt impacts not only potability of water, but also impact drinking water infrastructure in terms of lifetime and leaks. Water contamination is an emerging and increasing problem for both private well owners and municipal water suppliers. Salt, sodium chloride, spikes have caused changes in water chemistry triggering the lead in solder to be released into the water. Chloride is an aggressive ion that exacerbates corrosion, especially galvanic corrosion in hot water heaters and at soder points where pipes are joined.

Chloride levels are rising nationally in freshwater sources, not just here. We increasingly need to reuse water as we do with the Occoquan Reservoir to meet water demand and with increased population pavement and road building increases and the use of road salt for de-icing also increased especially in the northeast.  Road salt is applied to de-ice roads in the winter for highway safety, with more than 18 million metric tons applied annually and most used in northeastern and midwestern states to ensure public safety. The more paved roads we build, the more salt is used in the winter.

The ICPRB, the Virginia Department of Environmental Quality (VDEQ) and the Northern Virginia Regional Commission have joined together to develop a voluntary Salt Management Strategy published in 2020 to reduce the largest source of salt/ chloride to the Potomac, its tributaries and the Occoquan Watershed, but this alone may not slow the increasing salinization of our source water for drinking as road construction continues at an alarming pace. As we try to encourage the adoption of the voluntary salt management strategy, we keep building roads and paving over the county.

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

We need to do more. There are significant other sources of salt in our watershed. A very obvious one is self-regenerating salt-based water softeners used both in homes and for industries like data centers that use vast amounts of water for cooling. In days past, at the first sign of hard water or often other issues, a salt based conventional water softening system was installed.  Water softening is basically an ion exchange system. The water softening system consists of a mineral tank and a brine (salt) tank. Eventually the surfaces of the beads in the mineral tank become coated with the calcium and magnesium. To clean the beads, a strong salt solution held in the brine tank is flushed through the mineral tank. Sodium chloride is typically used. The excess sodium solution carrying the calcium and magnesium is flushed to the septic system or waste water system and into the environment or Occoquan Reservoir. Some sodium ions remain in the tank attached to the surfaces of the beads and the resin is now regenerated and ready to continue softening the water.

The amount of sodium in water conditioning systems is a real problem for humans and the environment. All of the salt is released into the septic system or wastewater system that does not remove salt. Ultimately, the sodium chloride solution reaches the leach field and groundwater or pass throught the wastewater treatment system and are released to the surface water. Conventional salt-based water softening systems contribute to three problems:
The brine backwash can cause salt buildup in groundwater and other aquatic environments. Water softeners release sodium chloride and other chloride salts into the environment. This can adversely affect groundwater aquifers, streams and rivers. This can add to problems in areas that are already suffering from high concentrations of salts due to road salt application.

Brine backwash in the conventional septic tank had interfered with the digestion of the cellulose fibers and reduced scum layer development, carryover of solids and grease to the distribution system. The brine back wash system uses water to flush itself out regularly. The EPA estimates in that a conventional softener can use up to 10,000 gallons per year for the backwash cycle. 

At this time California, Michigan, Connecticut, Arizona, Massachusetts, and Texas have laws or regulations that limit the use or outright ban traditional salt based water softeners. Personally, I am not a fan of traditional water softeners. I do not care to add all that sodium to my diet. If you are on public water, you should not need to soften your water.

Wednesday, April 13, 2022

Test Your Well Water-Every Year

Yesterday morning following the instructions from the Extension Office, I collected water samples from my kitchen sink and put the sample bottles in the refrigerator. Then after having coffee and feeding the animals I drove the samples (in a insulated lunch pack on ice) to the Extension Office in Manassas. Once a year the Virginia Cooperative Extension in Prince William County holds a well water testing clinic where water samples are tested for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria all for the low cost of $65. I test my well every year and the Extension program is one of the cheapest ways to get it done.  Judging by the number of people who participate in the clinic each year (a hundred or so out of thousands of well owners in Prince William County) most people do not test their well regularly. You should.

While the U.S. Environmental Protection Agency (EPA) regulates public water systems, the responsibility for ensuring the safety and consistent supply of water from a private well belongs to the well owner-in this case me. These responsibilities should include knowing the well’s history and planning for equipment replacement , testing the water quality annually (or more often as needed), and having the well system and its components inspected regularly by a well driller licensed well service company. 

In Virginia installation of private wells is regulated by the Department of Health, responsible for approving the location of a well, inspecting the well after construction to verify proper grouting and adequate water yield, maintaining records of the well driller’s log, verifying the most basic potability of water by requiring at a minimum bacterial testing after completion. Then you are on your own to do what you deem best.

If your home has a drinking water well that is contaminated, it could significantly impact your health and the value of the property. When you buy a home lenders require that a well be tested for coliform bacteria contamination, nothing more. For many homeowners this was the only time their well was ever tested. Total coliform bacteria is always present in manure and sewage, but is also present in soil and vegetation and surface water. The presence of coliform bacteria can mean that surface water is getting into the well either directly through a failing casing or grouting or improper construction or well cap or by other means. Absence of coliform bacteria only means that water is not contaminated by septic and surface runoff, but the water might be contaminated from other sources.

Due to its protected location underground, most groundwater is naturally clean and free from pollution. Typically, the deeper the well the less likely is it to be contaminated; however, there are a number of threats to drinking water: improperly disposed of chemicals (pesticides and oil poured down the drain of a home with a septic system); animal wastes; pesticides; human wastes (that nearby septic system); wastes buried underground or leaking fuel tank; and naturally-occurring substances can all contaminate drinking water and make it unsuitable for drinking or make the water unpleasant to drink. Homes built on former disposal sites- farm dumps, landfills or former military operations are particularly susceptible to contamination. Former agricultural properties should be tested for pesticides, fuels and solvents because farmers often have fuel tanks and repaired farm equipment with solvent that were improperly disposed of over the years. Hopefully, all those tests were done before you bought the home (I know I did).

 The nightmare scenario is what happened in Sterling, Virginia. The short story is that for twenty or thirty years homeowners in that community in in Loudoun County were drinking water contaminated with TCE and its degradation products. The homes had been built on and old landfill and back in 1988 the Loudoun County Department of Health and the EPA had found traces of TCE, its degradation products and pesticides in three residential wells, but because the contamination was below the regulated maximum contaminant level (MCL) no further investigation was performed. Apparently, the oddity of finding a solvent in groundwater in a residential community did not immediately prompt further investigation. The water was within safe limits and thus was fine.

However, the water in the neighborhood was not fine. In 2005, 68 more wells (in the community) were tested by the Health Department. “Forty-five wells tested positive for TCE; 17 of these wells contained concentration of TCE above the maximum contaminant level (MCL) of 5 micrograms per liter (mcg/L) while 28 wells contained TCE, but below the MCL.”  The site was declared a CERCLA (Superfund) site in 2008. Between 1988 and 2005 no testing was done on the individual homeowner wells. The water was consumed by the young and old and the homes were bought and sold. If your home had been declared within a Superfund site, it is very likely that the value of the home would be impacted.

Everything that is known about the groundwater in Prince William County is because a study of the groundwater was performed by the U.S. Geological Survey (USGS) in 1991 to study the extent of TCE contamination from the Superfund site in Manassas. They did not test every inch of the county nor look for other contaminants, but felt that they were able to find the extent of the TCE contamination plume. To be prudent and smart you need to test a well for likely sources of contamination. When I was working as an Environmental Engineer, the biggest challenge was to adequately research the history of a property and then test the soil and groundwater for contamination in the areas most likely to be contaminated. Testing is expensive, so it is virtually impossible to fully test soil and groundwater for everything and it is very easy to miss the contamination if the study is not planned properly and you do not understand the geology.

When buying a single family home, you do not have any of this information or resources available to you. Neighbors can be useful or just have no understanding of environmental and groundwater issues and tell you nonsense they’ve heard. If someone asked me about groundwater in my community or my opinion about any specific well, I would tell them, but they would not know my level of expertise. While there are some good historical records available for industrial and commercial properties there is very little information available for residential properties. The department of health often has some useful information about water quality in the county and septic systems, but rarely has any water analysis data available. Though, it was a Department of Health employee who originally found the Prince William County TCE contamination.  

Your best option is to do a broad scan of the well water quality. There are screening packages available from U.S. EPA certified laboratories like  National Testing Laboratories that screen water wells for all the primary and secondary contaminants in the Safe Drinking Water Act. The WaterCheck with pesticides package from National Testing Laboratories is a broad stroke test, testing the water for 103 items including Bacteria (Total Coliform and E-Coli), 19 heavy metals and minerals including lead, iron, arsenic and copper (many which are naturally occurring, but can impact health); 6 other inorganic compounds including nitrates and nitrites (can indicate fertilizer residue or animal waste); 5 physical factors including pH, hardness, alkalinity; 4 Trihalomethanes (THMs) and 47 Volatile Organic Chemicals (VOCs) including Benzene, Methyl Tert-Butyl Ether (MTBE) and Trichloroethene (TCE). The pesticide option adds 20 pesticides, herbicides and PCBs.  This testing can be done for a few hundred dollars.    

I’ve done that kind of “full analysis” on my well a few times. These days I test my well annually in the annual water quality clinic sponsored by the Extension office. Groundwater quality is driven by geology, well construction and condition, nearby sources of groundwater contamination, and any water treatment devices and the condition and materials of construction of the household plumbing. Year to year, outside sources of groundwater contamination are not likely to change except with changes in land use. Thus, it is not necessary to test for industrial contaminants every year. To ensure my drinking water remains safe it is important to maintain my well (I replaced the cap two years ago), test it regularly and understand your system and geology. I do not have any water treatment in my house, I drink the water just as it is from the ground. If however, you have water treatment equipment in your home you might want to get test the water before and after the treatment equipment each year to make sure you have the right equipment for your water and that it continues working properly.


Sunday, April 10, 2022

IPCC Releases final Part of the 6th Report

In case you missed it, the Intergovernmental Panel on Climate Change, IPCC, after a slight delay released the final portion of the sixth report. To a large part it was gloom and doom with  smiley face stuck on it. The scientists find that:

  • Total net anthropogenic GHG emissions are now 59  gigatonnes of CO2 equivalents a year.
  • CO2 emissions per year have continued to grow annually (except to a brief reduction at the beginning of the pandemic).
  • Despite pledges made in in the Paris Accord and updated in Glasgow at the COP 26 meeting the world is still on track for a 2-2.9 degree Celsius warming.
  • World emissions would have to peak by 2025 and fall 43% by 2030 to have a shot of holding temperature increase to 1.5 degrees Celsius. This is virtually impossible.

We still need to cut emissions to minimize the damage and impacts to the people, animals and planet, but there will still be damage. The report give several strategies to achieve that. They all boil down to electrifying transportation, converting the electric grid to renewable energy and increasing carbon uptake using mostly agriculture, nature and trees.

Regional contributions to global GHG emissions continue to differ widely. Variations in regional, and national per capita emissions partly reflect different development stages, but they also vary widely at similar income levels. However, the 10% of households with the highest per capita emissions contribute a disproportionately large share of global household GHG emissions. (That is all of us, especially in North America and the other developed nations.)

“In 2019 (the last year included in the report), approximately 34% (20 GtCO2-eq) of total net anthropogenic GHG emissions came from the energy supply sector, 24% (14 GtCO2-eq) from industry, 22% (13 GtCO2-eq) from agriculture, forestry and other land use, 15% (8.7 GtCO2-eq) from transport and 6% (3.3 GtCO2-eq) from buildings. If, however, emissions from electricity and heat production are attributed to the sectors that use the final energy, 90% of these indirect emissions are allocated to the industry and buildings sectors, increasing their relative GHG emissions shares from 24% to 34%, and from 6% to 16%, respectively. After reallocating emissions from electricity and heat production, the energy supply sector would account for 12% of global net anthropogenic GHG emissions.”

The report's authors said they had "high confidence" that unless countries step up their efforts to cut greenhouse gas emissions, the planet will on average be 2.4C to 3.5C (4.3 to 6.3 F) warmer by the end of the century — a level experts say is sure to cause severe impacts for much of the world's population.” The report made it clear that there is no feasible pathway to achieving the GHG emissions reductions that will hold global warming within 1.5 degrees Celsius.   

Wednesday, April 6, 2022

New Study Models Old Faithful

Finn, C.A., Bedrosian, P.A., Holbrook, W.S. et al. Geophysical imaging of the Yellowstone hydrothermal plumbing system. Nature 603, 643–647 (2022).

from VA Tech and USGS the imaging equipment

Many of us have childhood memories in the days before life was digital of road trips across America to visit Yellowstone National Park and see the eruptions of Old Faithful, the bubbling mud cauldrons of Artists Paint Pots, the crystal-clear water and iridescent colors of Grand Prismatic Spring, and the stacked travertine terraces of Mammoth Hot Springs. These wonders of the natural world are just a few of the over 10,000 active hydrothermal features formed by the interaction of ground water with the heat remaining from the ancient volcano that formed Yellowstone National Park. 

Now, in a newly published study Scientists from the U.S. Geological Survey, Virginia Technical University, and Aarhus University in Denmark used a combined electrical and magnetic mapping technique deployed using a helicopter to see beneath the surface and reveal some of the secrets of the park hidden almost a mile beneath the ground. 

The survey technique took advantage of the fact that water is a much better electrical conductor than rock. They used a sensitive electromagnet to measure variations in electrical conductivity and magnetic properties between wet and dry rock. The electromagnet was an 80-foot-wide hoop dangling beneath a low-flying helicopter that crisscrossed the park for weeks, mapping the water below ground. The USGS described it as being like a medical CAT scan building an image using data from a set of surface detectors. The really hard part was building the model to translate the data gathered into a tangible three dimensional image.  

It took years of work to produce the images that show the park’s geology profoundly shapes its hot springs. Hot hydrothermal fluids ascend nearly vertically, from depths of more than 1 kilometer to arrive at the park’s major hydrothermal fields. Along the way, they mix with shallower groundwater flowing within and beneath the park’s volcanic lava flows, which also are visible in the images. Faults and fractures are the pathways of the hydrothermal waters, while lava flow boundaries control the shallow groundwater aquifers. As fluids travels up to the surface, local constrictions in the pathways help induce boiling, degassing or conductive cooling that produce the varying and wonderous thermal features at Yellowstone National Park. 

Knowing how it works does not reduce the wonder of its existence.  

Sunday, April 3, 2022

Comments on PW Digital Gateway and Comp Plan Changes

The streams, rivers and groundwater in the Occoquan Watershed in Prince William County are at risk of degradation from PW Digital Gateway,  and the land use and zoning changes in the 2040 Comprehensive Plan Update.  As demand for local lands and resources increases and landowners seek to maximize the sale value of their land, developers look to create massive industrial development in the Rural Crescent where there is inadequate road systems, no stormwater infrastructure, no public water supply, no available source for cooling water supply, no sewage, etc.  

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

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

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 during wet weather and reclaimed water from UOSA during dry weather. Sodium concentration in the reclaimed water is higher than in outflow from the two watersheds right now and will rise with the increase in blowdown from data center cooling and increased population density. However, increasing paved areas increases the salt runoff into the watershed.

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 in Prince William County.

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

Fairfax Water has taken the unusual step to ask that Prince William County convene the Occoquan Basin Policy Board and oversee a Comprehensive Study of the proposed PW Digital Gateway CPA and the 2040 Comprehensive Plan Update to evaluate their impact on water quality in the Occoquan Reservoir before any action is taken. The cost to restore the basin and treat the water is in the billions of dollars that will be borne by us, the residents who remain.

The Occoquan Watershed Model was developed over decades 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, yet did not use it to evaluate the wholesale change in the land use of the county. 

Prince William County failed also to consider the impact of the proposed zoning changes to the quality, availability and sustainability of the water supply 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.