Wednesday, March 31, 2021

Drought and Water Quality

The article below is extracted from the press release from the U.S. Geological Survey (USGS) and the underlying study “Assessing the Impact of Drought on Arsenic Exposure from Private Domestic Wells in the Conterminous United States” published in Environmental Science and Technology at  

From 2010 to 2018, the U.S. experienced three droughts of historic proportions including the Southern Plains drought (2010–2011), a 2012 drought that impacted a large portion of the continental United States, and a persistent West Coast drought. The drought of 2012 in the U.S. was one of the worst droughts on record. On September 25, 2012, that drought encompassed 66% of the continental United States. This was the largest extent of a drought since the U.S. Drought Monitor began keeping records in 2000.The regions of the continental United States that were hardest hit by the 2012 drought were the West, Great Plains, Midwest, and Southeast. Only New England and the Pacific Northwest regions did not experience drought during 2012.

Climate projections are for much of the United States to grow warmer and drier. We are fortunate that here in Virginia that the climate projections indicate that the mid-Atlantic states, on average, will continue to get “wetter.” However, climate scientists also warn that extreme conditions- floods and droughts, will become more severe. Unlike other climate-related hazards such as flooding, hurricanes, and heat waves, drought typically occurs over longer period of time ranging from months to years. There is a need for better understanding of potential drought impacts to public health and safety in order to properly prepare.

Scientists at the U.S. Geological Survey are beginning to look at some of the impacts that drought might have on water quality. In the study “Assessing the Impact of Drought on Arsenic Exposure from Private Domestic Wells in the Conterminous United States,” USGS scientists utilized a statistical model as a tool to assess the potential impact of drought on arsenic exposure from domestic wells. A limitation of this approach is that statistical models may not account for all interactions between the climate and arsenic concentrations in domestic well water. However, arsenic is primarily a geogenic contaminant often seen in drinking-water supply wells, so a simplified estimate it has validity. This statistical method is widely used to understand the potential impact of climate change on the environment, especially at large spatial scales where climate is a dominate variable.

As can be seen below, even without drought conditions, relatively large numbers of people are estimated to be exposed to elevated arsenic levels in private domestic well water. Based on the model estimates, the population with arsenic concentrations greater than 10 μg/L (the EPA Safe Drinking Water limit) is 2.7 million or 7.1% of domestic well users.  Under non-drought conditions, the largest populations potentially exposed to high levels of arsenic are in Ohio (approximately 241,000 people), Michigan (226,000 people), Indiana (162,000 people), California (157,000 people) and Maine (121,000 people).

When the model was run under drought conditions, the overall high-arsenic domestic well population increased from 2.7 million to 4.1 million people, or a 54% increase. The model predicted that the states with the largest populations with elevated arsenic levels in private domestic well water during drought would be Ohio (approximately 374,000 people), Michigan (320,000 people), Indiana (267,000 people), Texas (200,000 people) and California (196,000 people).

“The population potentially exposed to arsenic levels exceeding the EPA standard during simulated drought conditions amounts to roughly one-tenth of the estimated 37.2 to 43.2 million people in the continental U.S. who use domestic wells for household water supply,” said Melissa Lombard, a USGS hydrologist and lead author of this study.

According to “NSF International is anot-for-profit organization that develops stand­ards, product testingprocedures, and certification services for products including water treatmentdevices. NSF has certified point-of-use reverse osmosis and distillationdevices for the reduction of arsenic in drinking water. Pretreating waterthrough chlorination or oxidation and filtration may be necessary to makereverse osmosis devices effective for arsenic re­moval.”


Sunday, March 28, 2021

BP money goes to Louisiana to Punch a Hole in the Levee

 The Deepwater Horizon oil spill resulted in the covering of about 1,100 kilometers of Louisiana wetland coastline with crude oil. The heaviest damage occurred in the Barataria Basin, resulting in substantial damage and injury to natural resources and wildlife in the basin. However, there is some good that can result from that disaster. The long term erosion of the coastline had caused the fragile condition of the basin even before the spill which  served to accelerate the process.

The Barataria Basin is located immediately south and west of New Orleans, Louisiana. The Barataria Basin is bounded on the north and east by the Mississippi River from Donaldsonville to Venice, on the south by the Gulf of Mexico, and on the west by Bayou Lafourche. The Barataria Basin is an irregularly-shaped area bounded on each side by a distributary ridge formed by the present and former channels of the Mississippi River. A chain of barrier islands separates the basin from the Gulf of Mexico. Barataria Basin suffered the brunt of the Deepwater Horizon oil spill damage.

The State of Louisiana and the federal Trustees that negotiated the Deepwater Horizon Natural Resource Damages settlement allocated $4 billion, almost half of the total settlement amount, to restoring Louisiana’s wetland, coastal, and nearshore habitats. The State of Louisiana recognized the need for increasing the resiliency and sustainability of this highly productive Gulf ecosystem following Hurricanes Katrina and Rita in 2005. The Louisiana Legislature created CPRA to coordinate the local, state, and federal efforts to achieve coastal protection and restoration and combat Louisiana’s coastal land loss crisis.

After 2007, state and federal investments in the protection and restoration of Louisiana’s coast increased dramatically, but money could only be allocated slowly. These investments allowed for the implementation of improvements to Louisiana coastal communities’ hurricane protection systems, as well as shoreline protection, marsh creation, barrier island repairs, and other projects. These projects taught the engineers and planners involved in this effort many lessons and allowed them to begin to plan for and evaluate larger-scale efforts. Then the Deepwater Horizon spill happened and ultimately resulted in the $4 billion settlement to restore Louisiana’s wetlands.

Now, with the concurrence of the Army Corps of Engineers it was decided that the best method of restoration would be to cut a hole in the levee  near Myrtle Grove and install gates that would allow continual large-scale sediment diversion. Though there is the potential for some adverse impacts, the CPRA  determined that this preferred alternative will provide long-term ecosystem benefits and restoration of damaged estuary and would provide ongoing benefits to the Wetlands, Coastal, and Nearshore, and has a high likelihood of success, and would reduce future erosion. The Trustees also identified multiple potential benefits from such projects. These benefits included helping “maintain the Louisiana coastal landscape and its ability to overcome other environmental stressors by stabilizing wetland substrates; reducing coastal wetland loss rates; increasing habitat for freshwater fish, birds, and benthic communities; and reducing storm risks, thus providing protection to the essential nearby infrastructure” (DWH NRDA Trustees, 2016, page 5-25). The video below covers all the restoration going on in the Barataria Basin.

Wednesday, March 24, 2021

Fairfax Water and PFAS

In early March the Environmental Working Group (EWG) released the results of a a new analysis, they commissioned of tap water samples taken from various location throughout the Northern Virginia region. The EWG reported that they detected total PFAS in 19 samples of tap water ranged from about 6 parts per trillion, or ppt, in a state park in Fairfax County, to about 62 ppt in a public park in Prince William County. In 2019 the EWG had reported that the results from the sampling conducted as part of the EPA’s Unregulated Contaminant Monitoring Rule 3 from 2013 to 2015.  All results in Fairfax were non-detect, meaning that all results were below the detection limit of the test used. The analysis was conducted using EPA Method 537. In the Prince William County Service Authority Eastern service area was found to have 12 ppt of PFAS in 2014. This year’s findings were more wide spread and in some cases at a higher level.

Fairfax Water responded to the new release from EWG by stating that when they tested in 2013 to 2015 that no perfluoroalkyl substances (PFAS) were detected in Fairfax Water’s service area, and pointing out that:  “There is currently no established federal water quality regulation for any type of PFAS.  In May of 2016, The Environmental Protection Agency (EPA) established the health advisory levels at 70 parts per trillion (ppt) for Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS).  Both chemicals are types of PFAS.” In February 2020 and in February 2021 the EPA announced its intention to regulate PFOA and PFOS under the safe drinking water act. No limit was identified. In late 2020 the European Union (EU) issued a directive  setting a limit value of 500 ppt for total PFAS concentration in drinking water.   

Fairfax Water says “There are no treatment processesavailable for drinking water utilities that would not significantly increase water rates for customers. Nor would such treatments produce a demonstrated health benefit. “ It appears that they are going to see what concentration the EPA intends to regulate PFOS and PFOA for drinking water. Changing the water treatment chain at the Corbalis and Griffith water treatment plants would be necessary to treat the source water to remove PFAS. This would "significantly" increase the cost of water for all the residents of Fairfax and Prince William Counties. 

In May of 2016, The Environmental Protection Agency (EPA) established the health advisory levels at 70 parts per trillion (ppt) for Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic acid (PFOS). All the samples taken by EWG are below that level.  I do not know at what level the EPA or Virginia intends to regulate PFOS and PFOA at. Several states have set significantly lower levels for some PFAS contamination. Studies indicate that high concentrations of PFOA and PFOS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animal studies. The most consistent findings from human studies are increased cholesterol levels among exposed populations, with more limited findings related to cancer, thyroid hormone effects, other reproductive and developmental impacts in humans, infant birth weights and adverse effects on the immune system. The EWG is pushing for a federal limit if 1 ppt.

The source of PFAS contamination in the latest samples is not known. The level of PFAS in a sample of tap water is largely determined by the source of the water supply. However, the EWG speculates based on the location of the samples that the Occoquan Reservoir and/or the Occoquan watershed in Prince William, may be the source of the contamination. In February 2020, a malfunction released a large spill of PFAS-based firefighting foam from a hangar at Manassas Regional Airport, in the Occoquan River basin. It is not known whether the spill contaminated water supplies, but it is possible and would explain the difference in the sampling results reported in 2014 and 2020.

PFAS are synthetic fluorinated organic chemicals. Manufacturers have produced PFAS for a variety of industries and products, including surface treatments for soil/stain/water resistance; surface treatments of textiles; paper; metals; and for specialized applications, such as fire suppression for hydrocarbon fires, and have been widely used on military bases.

PFAS are resistant to metabolic and environmental degradation, are highly persistent in the environment and can bioaccumulate in humans; and therefore are often called “forever chemicals.” PFAS include a large number of important chemicals that can be used in some food packaging and can make things grease- and stain-resistant. They were used in firefighting foams and in a wide range of manufacturing practices. The result is that according to the CDC more than 95% of the U.S. population has measurable levels of PFOA and PFOS in their blood; and babies are born with PFOA in their blood.

Drinking water can be a source of exposure in communities where these chemicals have contaminated water supplies. Such contamination is typically associated with a specific facility, for example: an industrial facility where PFAS were produced or used to manufacture other products, or locations where firefighting foam was used such as oil refineries, airfields or other training facilities for firefighters.

Activated carbon or commonly granulated activated carbon (GAC) has been shown to effectively remove PFOS and PFAS from drinking water. The EPA says, “GAC can be 100 % effective for a period of time, depending onthe type of carbon used, the depth of the bed of carbon, flow rate of thewater, the specific PFAS you need to remove, temperature, and the degree andtype of organic matter as well as other contaminants, or constituents, in thewater.” Activated carbon treatment an inexpensive and readily available point of use treatment. “High-pressure membranes, such as nanofiltrationor reverse osmosis, have been extremely effective at removing PFAS. Reverse osmosis membranes are tighter than nanofiltrationmembranes.  Research shows that these types of membranes aretypically more than 90 percent effective at removing a wide range of PFAS,including shorter chain PFAS.”  

Sunday, March 21, 2021

Drinking Water in America 2021

Every four years, the American Society of Civil Engineers’ Report Card for America’s Infrastructure reviews and evaluates the condition and performance of American infrastructure. Below are highlights culled and clipped from thereport on the nations Drinking Water infrastructure.

Our nation’s drinking water infrastructure system is made up of 2.2 million miles of underground pipes that deliver drinking water to millions of people. Though there are more than 148,000 active drinking water systems in the nation, just 9% of all community water systems serve 78% of the population- over 257 million people. The rest of the nation is served by small water systems (about 8%) and private wells (about 14% of the population). There is a water main break every two minutes and an estimated 6 billion gallons of treated water is lost each day to leaks and water main breaks.

This sounds bad, but the grade for water infrastructure has gone up in the past four years from a D+ to a C-. The ASCE tells us there are signs of progress as federal financing programs expand and water utilities raise rates to reinvest in their networks. This action was spurred in large part by the growing public awareness of water system problems like Flint, Michigan, increasing incidents of broken pipes, boil water advisoried and others incidents that has made the public aware that water infrastructure cannot be ignored.

 The ASCE estimates that more than 12,000 miles of water pipes were planned to be replaced by water utilities across the country in 2020. That is still less than 1% of the water pipes. To maintain these systems properly around 1.3% of pipes should be replaced each year. In 2019, about a third of all utilities had a developed and implemented what they label a robust asset management program to help prioritize their capital and operations/maintenance investments. This is an increase from 20% in 2016.

Funding for drinking water infrastructure has not kept pace with the growing need to address the aging infrastructure. Despite the growing need for drinking water infrastructure, the federal government’s share of capital spending in the water sector fell from 63% in 1977 to 9% of total capital spending in 2017. We do not know how to maintain our equipment and infrastructure on an ongoing basis.

The U.S Environmental Protection Agency’s (EPA) Drinking Water State Revolving Fund (DWSRF) provides low-interest loans to state and local drinking water infrastructure projects, and states provide a 20% funding match. From 2013 to 2018, the DWSRF program grew from just over $2 billion in 2013 to nearly $3 billion in 2018, providing loans of increasing sizes to the states. This is all necessary because decades old drinking water infrastructure systems, stagnant or declining per capita water use, costs of regulatory compliance, and stagnant federal funding has resulted in many water utilities struggling to fund the cost of operations and maintenance of these systems. In our region the story is different- population growth along with demand from growing industry is expected to increase drinking water demand in the WMA. However, we have seen WSSA struggle do development a program to maintain their piping infrastructure and DC Water famously announced in 2012 (when their average pipe was 78 years old) that they had tripled the replacement rate for their pipes to 1% per year so that in 100 years the system will be replaced.

A recent survey found that 47% of the maintenance work undertaken by utilities is in reaction to a failure or water main break and not part of a preventive maintenance plan. This is no way to maintain an essential system. The EPA has regulates public drinking water supply through the Safe Drinking Water Act (SDWA). The EPA sets national health-based standards and determines the enforceable maximum levels for contaminants in drinking water. In 2019, the number of public water systems with health-based violations was 15% lower than in 2017.

Water utilities face the increasing challenge of keeping pace with emerging contaminants such as per- and polyfluoroalkyl substances (PFAS) which would require additional treatment to remove, lead and copper in drinking water, and the regulatory requirements needed to remain in compliance with the SDWA. Utilities in more rural communities and shrinking urban areas have a smaller rate-payer base, which results in less revenue and more difficulty in meeting the requirements of the SDWA and to maintain aging systems.

In addition, as the nation faces more frequent extreme weather events due, water utilities are taking action to increase the resilience of their systems to ensure safety and reliability. The America’s Water Infrastructure Act of 2018 required community water systems serving more than 3,300 people to develop or update risk assessments and emergency response plans. The law sets deadlines, all before December 2021, by which water systems must complete and submit the risk assessment and emergency response plans to the EPA. Hopefully, this will push water utilities to improve their operations further.

Wednesday, March 17, 2021

2021 Report Card for America’s Infrastructure

Every four years, the American Society of Civil Engineers’ Report Card for America’s Infrastructure reviews and evaluates the condition and performance of American infrastructure. The ASCE assigns letter grades based on the physical condition and needed investments for improvement. The 2021 Infrastructure Report Card released this month reveals America’s overall GPA is C-. This is the highest overall grade in 20 years that ASCE has been doing this. However, their report found that the long-term infrastructure investment gap continues to grow. That gap has risen from $2.2 trillion over 10 years in the last report to $2.59 trillion in the latest study, which translates to a funding gap of nearly $260 billion per year.

The individual 2021 grades ranged from a B for rail to a D- for transit. Despite some gains, 11 of the 17 categories received a grade in the D range. As you can see in the accompanying chart, five categories –aviation, drinking water, energy, inland waterways, and ports – went up from the last report card in 2017, while one category – bridges – went down. Stormwater is a new category which has no historical comparison. Stormwater, included in the 2021 report card for the first time as a stand-alone category, debuted with a grade of D. The grades are improving where there has been investment.

Drinking water advanced from a D in 2017 to a C- in the latest report card. The improvement reflects the “tremendous strides” that the drinking water sector made during the past four years spurred by the publicity from the water problems in Flint Michigan. The biggest change has been an increase in the pace at which water agencies are replacing their existing waterlines to eliminate lead service lines and waste. In its 2017 report card, the ASCE found that water utilities, on average, were replacing waterlines at a rate of 0.5% per year- a rate that would take 200 years to replace the water lines that only last about 75 years. In this report the ASCEE found that the replacement rate has increased significantly in the last four years, ranging from an average of 1.5 to 4.8 percent, depending on the utility. Water utilities found the will to raise rates to fund these capital projects after decades of underfunding maintenance and capital programs to keep water rates artificially low.

Today a growing number of drinking water utilities are developing asset management plans. It is reported that 29% of water utilities have asset management plans, up from only 20% in the 2017 report card; and another 55% of water utilities are developing asset management plans.

The energy sector has also see some improvement despite the rapid changes being seen in energy regulation. The U.S. energy sector has managed to maintain its power generating capacity even as it undergoes a major shift in the nature of its generation sources. The ongoing transformation from a mainly carbon-based system to one that relies more on renewable energy sources will necessitate extensive new transmission infrastructure to convey electricity from remote energy sources to where the demand is located.

The storm-hardening efforts by power utilities are beginning to make an impact. There is reported to have been a slight decrease in the number of outages, but the widespread power outages that have occurred in recent years in California as a result of wildfires and extreme weather, in Puerto Rico as a result of hurricanes and Texas as a result of extreme weather show just how much investment our power infrastructure needs and regulatory changes that are necessary to improve our systems.

“To build a transmission line, you have to contact, at a minimum, 47 different federal agencies. … It takes 10-plus years to permit a transmission line. We can build them in a year.” Otto Lynch, P.E., F.ASCE, F.SEI “It takes 10-plus years to permit a transmission line,” Lynch says. “We can build them in a year.” Of course, time is money. “There have been some lines (for which) the cost of permitting was five times higher than the cost (to build) the actual line,” he says. Infrastructure is the backbone of the U.S. economy. It is critical to every nation’s prosperity and the public’s health and welfare. For the U.S. economy to be the most competitive in the world, we need a first-class infrastructure system – transport systems that move people and goods efficiently and at reasonable cost by land, water, and air; transmission systems that deliver reliable, low-cost power from a wide range of energy sources; and water systems that drive industrial processes as well as the daily functions in our homes. Yet our investment in infrastructure has not kept up. In the first ASCE Report Card for America’s Infrastructure in 1988, America’s grade was about a C+. We have failed to maintain and expand the infrastructure built by our parents and grandparents and great-grandparents. 

Sunday, March 14, 2021

PFAS found in Northern Virginia Drinking Water

 Last week the Environmental Working Group (EWG) released the results of a a new analysis, they commissioned of tap water samples from throughout the Northern Virginia region. The results PFAS contamination at levels significantly higher than previously reported throughout the region.

Detected levels of total PFAS in 19 samples of tap water ranged from about 6 parts per trillion, or ppt, in a state park in Fairfax County, to about 62 ppt in a public park in Prince William County. These levels are much higher than samples previously taken in Northern Virginia. Like the previous samples, the latest samples were collected by EWG staff and volunteers and analyzed by an accredited private laboratory using Environmental Protection Agency–approved methods.

From EWG

PFAS are known as “forever chemicals” because they build up in our blood and organs, bioaccumulate, and do not break down in the environment. Though the level found is still below the U.S. Environmental Protection Agency’s (EPA) health advisory level of 70 ppt, that level is screening level for groundwater contamination, not a health based maximum contaminant level (MCL) for drinking water. In 2009 the EPA set the first health advisory level (HAL) for PFOA and PFOA at 400 ppt each. In 2016 EPA reduced the health advisory level to a combined 70 ppt for PFAS. They have not yet established a health based MCL. 

The compounds in EWG’s tests are a small fraction of the entire PFAS class of thousands of different chemicals with hundreds in current use. Studies have found that exposure to very low levels of PFAS can increase the risk of cancerharm fetal development and reduce vaccine effectiveness.

Other states with extensive PFAS drinking water contamination have set more health-protective limits or lower advisory levels than the EPA to protect their residents. For example, New Jersey has set a legal limit of 13 ppt for perfluorononanoic acid, or PFNA, and proposed enforceable limits of 14 ppt for PFOA and 13 ppt for PFOS. Other states such as Washington, Michigan, and North Carolina are conducting additional testing to further evaluate the extent of contamination in drinking water. It is time for the Virginia Department of Environmental Quality to step in to protect our residents.

In February the U.S. EPA made the final determinations to regulate two contaminants, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) n drinking water and to not regulate six other PFAS contaminants. EPA will begin the process to develoop a primary drinking wate standard for PFOS and PFOA.

The source of PFAS contamination in the latest samples is not known. The level of PFAS in a sample of tap water is largely determined by the source of the water supply. However, the EWG speculates based on the location of the samples that the Occoquan Reservoir and/or the Occoquan watershed in Prince William, may be the source of the contamination. In February 2020, a malfunction released a large spill of PFAS-based firefighting foam from a hangar at Manassas Regional Airport, in the Occoquan River basin. It is not known whether the spill contaminated water supplies, but PFAS-based firefighting foams have been used for decades on military bases.

EWG’s latest tests represent a single sample from each site at a single moment in time. The EWG says that the test results are likely representative of the water in the area where the sample was taken but are not intended to identify specific water systems. EWG calls on all community water systems in Northern Virginia to conduct their own tests and release the results to the public as soon as possible. You can, however; take steps to protect yourself and your family. 

PFAS dissolves in water, and combined with their chemical properties means that traditional drinking water treatment technologies used at water treatment plants are not able to remove them. However, activated carbon adsorption, some 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.

NSF, UL, Water Quality Association or CSA Group certification are organizations that certify water treatment products. To earn certification, a manufacturer must undergo testing to confirm that the unit meets all chemical reduction claims and is structurally sound. NSF International, a testing and certification company, developed a certification standard for removal of PFOS and PFOA in 2016. The certification requires that the filter reduce these two chemicals only to EPA’s health advisory level of 70 ppt, but that level may not satisfy your current concerns. Units that are labeled as effective for removing pesticides (such as Aldrin) and volatile organic compounds should also be effective for PFOA and other PFCs.

Activated carbon treatment is the most studied treatment for PFAS removal. Activated carbon is commonly used to adsorb natural organic compounds, taste and odor compounds, and synthetic organic chemicals in drinking water treatment systems. This is an inexpensive and readily available point of use treatment. 

Activated carbon or commonly granulated activated carbon (GAC) has been shown to effectively remove PFAS from drinking water when it is used in a flow through filter mode after particulates have already been removed. EPA says, “GAC can be 100 % effective for a period of time, depending on the type of carbon used, the depth of the bed of carbon, flow rate of the water, the specific PFAS you need to remove, temperature, and the degree and type of organic matter as well as other contaminants, or constituents, in the water.”

Another treatment option is anion exchange treatment. There are two broad categories of ion exchange resins: cationic and anionic. Only the positively charged anion exchange resins (AER) are effective for removing negatively charged contaminants, like PFAS. Water softeners remove cations (positively charged ions such as calcium and magnesium) and are not what you need to remove PFAS.

AER has shown to have a high capacity for many PFAS; however, it is typically more expensive than activated carbon filtration. According to the EPA “of the different types of AER resins, perhaps the most promising is an AER in a single use mode followed by incineration of the resin. One benefit of this treatment technology is that there is no need for resin regeneration so there is no contaminant waste stream to handle, treat, or dispose.” It is unclear what the regulatory requirements are for the PFAS waste stream.

The final option is high-pressure membranes, such as nanofiltration or reverse osmosis. These have been found to be extremely effective at removing PFAS.. This technology depends on membrane permeability, and reverse osmosis membranes are tighter than nanofiltration membranes. A standard difference between the two is that a nanofiltration membrane will reject hardness to a high degree, but pass salts; whereas reverse osmosis membrane will reject all salts to a high degree (which is why it’s used for desalinization). This also allows nanofiltration to remove particles and hardness while retaining minerals that reverse osmosis would likely remove.

EPA states that “research shows that these types of membranes are typically more than 90% effective at removing a wide range of PFAS, including shorter chain PFAS.” As EPA points out: “Approximately 20% of the feedwater is retained as a high-strength concentrated waste. A high-strength waste stream at 20% of the feed flow can be difficult to treat or dispose, especially for a contaminant such as PFAS...” 

Overall, activated carbon filtration is the least expensive and simplest solution. It can be point of use or whole house and an added advantage is that is polishes the water leaving it tasting very good. In 2007 the state of Minnesota commissioned a study of the effectiveness of activated carbon filtration and reverse osmosis devices in removing PFAS you see the entire report at the link.  they found to be effective.   

Wednesday, March 10, 2021

Small Area Plan for Independent Hill

Independent Hill Small Area Plan would create a pathway for a mixed-use development in an agriculturally zoned area along route 234 known as Independent Hill. The plan would amend the comprehensive plan to allow more than 100 new homes in the area along with business and industrial and have 41 acres in the Rural Crescent rezoned for public facility/office use that would allow for a new data center.

The Board of County Supervisors seems inclined to eliminate the Rural Crescent protections which the Rural Crescent provided to our regional water resources and protecting the Prince William County taxpayer and water and electricity rate payer from the expense of building the infrastructure to bring water, sewage and power to the rural area (in addition to schools and roads) so that data centers can have cheaper water and electricity than in the west and northeast and developers can continue to turn Prince William County into Fairfax where the tax rate continues to need to be increased to supply services and schools to residences whose own taxes does not cover their additional costs.

To evaluate the Rural Crescent you must consider its impact on water resources and water ecology. While the Rural Crescent may have been the wrong policy to preserve our agricultural heritage, it has been a success at preserving water resources, protecting our groundwater and supporting the ecosystem of our county. In addition, continued redevelopment of areas with preexisting infrastructure would allow Prince William County to improve storm water management in those areas and score nutrient points for the EPA mandated TMDL as well as revitalize older areas of the county and support of sustainable development. The Rural Crescent is about water, and the costs to build out the infrastructure to support the rural area and replace the groundwater resources diminished by development.

Prince William Service Authority, PWSA, obtains most of the drinking water they distribute in the county wholesale from Fairfax Water. Besides purchased water from Fairfax Water, PWSA operates the Evergreen water wells that draw water directly from the Culpeper Basin and thousands of home owners have private wells that also draw from the aquifer. The Virginia-American Water Company also distributes water purchased from Fairfax Water. Any changes in land use have the potential to negatively impact groundwater, the watershed and the Occoquan Reservoir and significantly increase demand for water.

Back in 2009 Amazon estimated that a 15 megawatt data center can require up to 360,000 gallons of water a day- that is equivalent to more than 1,000 households. In addition, their power usage is a 24/7 load- a base load not easily replaced by renewable power sources. Northern Virginia reportedly has 166 data centers. This represents 1,027 megawatts of power capacity-more than anywhere in the nation. Sixty percent of the currently planned data centers nationally are to be built in Northern Virginia. That represents a tremendous ongoing demand for power and water. 

According to the U.S. Geological Survey total water consumption in the USA in 2015 was 321 billion gallons per day, of which thermoelectric power used 133 billion gallons, irrigation used 118 billion gallons and 39 billion gallons per day went to supply 87% of the US population with potable water. Lawrence Berkeley National Laboratory reported in 2014 that data centers consume water both indirectly through electricity generation (traditionally thermoelectric power) and directly through cooling. Data centers compete with other users for access to local resources. Amazon’s medium-sized data center (15 megawatts (MW)) uses as much water as three average-sized hospitals according to “Data centre water consumption” by David Mytton an article published in Nature in last month. In addition, more than half of this water ispotable.

The County Board of Supervisors need to STOP and study what the costs of these zoning and comprehensive plan changes are to our water resources and the expense that the community will have to bear to build out the infrastructure to support these plans BEFORE THEY APPROVE these changes.

Sunday, March 7, 2021

Satellites track the Water Cycle on Planet Earth


Though the recent landing of the Perseverance Rover on Mars has drawn our attention, it is important to recall (or know) that NASA is also gathering data on our own planet, Earth. The latest research was published last week in the journal” Nature.” Using data gathered by NASA’s Ice, Cloud and land Elevation Satellite 2 (ICESat-2), launched in September 2018, and the older Landsat mission jointly overseen by NASA and the U.S. Geological Survey, this new research begins the investigation of mankind’s impact on freshwater resources and the planet’s water cycle.  

NASA scientists conducted the first global accounting of fluctuating water levels in Earth’s lakes and reservoirs. Though the scientists had not expected it, they found that reservoirs made up the majority of total variability of water storage despite the fact that natural lakes and ponds outnumber human-managed reservoirs by more than 24 to 1. The variability in reservoirs only makes sense, you build a reservoir when you need to store water for later; but the amount of fluctuation was controlled by human action is an indication of how much of the surface fresh water is being used by mankind. It will be interesting to see how droughts impact this number during a longer duration study.  

ICESat-2 gathers information by sending 10,000 laser light pulses  down to Earth every second. When reflected back to the satellite, those pulses deliver high-precision surface height measurements for every 28 inches along the satellite’s orbit. Using the trillions of data points collected, scientists can measure volume of Earth’s lakes and ponds over time. The scientists used the Landsat two-dimensional maps of bodies of water and their sizes, providing them with a comprehensive database of the world’s lakes, ponds, and reservoirs. Then, ICESat-2 added the third dimension – height of the water level.

The scientists found from season to season, the water level in Earth’s lakes and ponds that are natural and unmanaged fluctuate on average about 8.6 inches each year. However, the water level of human-managed reservoirs fluctuates on average nearly four times that amount – about 34 inches each year. Still the volume in human managed reservoirs has to exceed natural ponds and lakes by more than 6 to 1 for the majority of fluctuation to be attributed to human management.  

Understanding that variability and finding patterns in water management really shows how much we are altering the global hydrological cycle,” said Dr. Sarah Cooley, a remote sensing hydrologist at Stanford University in California, who led the research. “The impact of humans on water storage is much higher than we were anticipating.”

In natural lakes and ponds, water levels typically vary with the seasons. In reservoirs, however, managers influence that variation – often storing more water during rainy seasons and diverting it when it’s dry, which can exaggerate the natural seasonal variation, Cooley said.

Dr. Cooley and her colleagues found regional patterns as well – reservoirs vary the most in the Middle East, southern Africa, and the western United States, while the natural variation in lakes and ponds is more pronounced in tropical areas.

In the future the scientists will investigate how human activity and climate alters the availability of freshwater. As the ever-growing populations place more and more demands on freshwater, and climate change alters the way water moves through the hydrological cycle, studies like this can illuminate how water is being managed, Cooley said.

This data could eventually be used for better water management to maximize water availability as populations continue to grow and the climate continues to change.

For more information on ICESat-2, visit

To read the full report Human alteration of global surface water storage variability | Nature

Wednesday, March 3, 2021

Prince William Well Water Clinic Coming Soon

There is still time to register for the Prince William County Extension well water clinic this month. To keep everyone safe the kit pick-up and drop off with be a drive by at the Extension Office. Introduction and sampling instructions will be presented by an online video and results and interpretation will be by Zoom meeting. You have until March 22, 2021 to register pre-pay online. For registration and pre-payment go to Be aware they will send multiple email confirmations- a receipt and confirmation of registration from the VCE Programs email and a payment receipt from the Bursar at Va Tech.

Water samples will be tested for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria. This is a bargin since sample kits will be $65 this year.

The Prince William Drinking Water Clinic has 4 parts:

1. Watch Kick-Off Meeting PowerPoint & How to Collect Water Sample using links below:
Kickoff Meeting PowerPoint and How to Collect Water Sample

2. Sample Kit Pickup- on Saturday, March 27th from 9:00am-12:00pm (noon) at the VCE Office, 8033 Ashton Ave, Manassas 20109. This is a drive-through pick up (remain in your car, masks are required. There will be a VCE tent and signs with directions in the parking lot)

3. The Sample Drop Off on Wednesday, March 31st from 6:30am-10am ONLY at the VCE Office, 8033 Ashton Ave., Manassas 20109. (Physical distancing measures will be in place and masks are required). THeVCE tent and signs with directions will be in the parking lot)

4. Results Interpretation Meeting (Zoom)-on Monday, May 10th, 7:00pm-9:00pm, 
there will be a live Zoom interpretation meeting which will explain the report, include a discussion, and answer questions on dealing with water problems. Zoom link and details will be emailed to everyone who registers.

Household water 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. To ensure safe drinking water it is important to maintain your well, test it regularly and understand your system and geology. If you have water treatment equipment in your home you might want to get two test kits to test the water before and after the treatment equipment to make sure you have the right equipment for your water and that it is working properly.