Water Clinic in Prince William

The Virginia Cooperative Extension (VCE) Office will be hosting a drinking water clinic for well, spring and cistern owners in Prince William County as part of the Virginia Household Water Quality Program. The Prince William VCE welcomes our neighbors from Loudoun, Fairfax, and Fauquier (and anyone else in Virginia willing to drive to the clinic to join us). A statewide grant from USDA Cooperative State Research, Extension and Education Service that allow Virginia to hold and subsidize the cost of the analysis for the water clinics in a dozen or more counties each year. To sign up for the program please call 703-792-6285 or email  jgraham@pwcgov.org. Please register as soon as possible so that the Prince William VCE Office can order enough test kits.

The program consists of two meetings- one to get instructions and test kits, and the other a month later to get results and provide interpretation and recommendations. Samples will need to be dropped off at the VCE Prince William Office for analysis a day and a half after the first meeting. The samples will be analyzed for 14 chemical and bacteriological contaminants and cost only $49. Comparable analysis at a private commercial lab would cost $150-$200. Samples will be analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria.

 The Kickoff Meeting will be on November 5, 2012 at 7 - 8:30 pm at the Old Courthouse, 9248 Lee Avenue  in Manassas, VA 20110

A brief presentation will be given to discuss common water quality issues in our area and instructions for how to properly collect the water samples from your tap. Water sampling kits will be distributed with written sampling directions and a short survey about your water supply for data gathering purposes. Checks (or money orders) for $49 to cover the cost for the analysis and sampling kits will be collected. A friend or neighbor may drop off your check and pick up your sampling kit.

The samples should be taken early Wednesday morning and then dropped off on Wednesday November 7, between 6:30am and 10am at the VCE  Prince William Office, at 8033 Ashton, Suite 105, Manassas  20109

Results Interpretation Meeting will be held on December 5, 2012, 7-8:30 pm once more at the Old Courthouse 9248 Lee Avenue, Manassas, VA 20110

Participants will receive their confidential water test results. A presentation will be given that explains what the numbers on the test report mean and what possible options participants may consider to deal with water problems. Experts will be on hand to answer any specific questions you may have about your water and water system. I will be one of volunteers present to help with the program. Come join us.

Just because your water appears clear doesn’t necessarily mean it is safe to drink. You cannot taste bacterial contamination from human and animal waste, nor nitrate/ nitrite contamination which can in excessive levels be deadly to newborns and infants. Since bacterial contamination cannot be detected by taste, smell, or sight, all drinking water wells should be tested at least annually for Coliform bacteria and E Coli. Testing is the only way to detect contamination in your water. Testing is not mandatory, but should be done to ensure your family’s safety. The Virginia Private Well Regulations only specify construction requirements. There are no requirements for maintenance or water testing after a well is approved either on a state or national level. Maintenance of your well and ensuring that water is safe to drink is the responsibility of the owner.

 Under the Safe Drinking Water Act the U.S. EPA requires that all public water supplies be tested for a list of 80 primary contaminants on a regular basis and meet these minimum standards. In addition, EPA has secondary standards for less hazardous substances based on aesthetic characteristics of taste, smell and appearance, which public water systems and states can choose to adopt or not. Neither the primary nor secondary safe drinking water standards apply to private wells, but these standards can be used as guidance to determine what levels of water constituents is too high and should be addressed.  Contamination from human and animal waste and chemicals can be real health hazards and should be addressed immediately. However, most of the water quality issues with private wells are from naturally occurring contamination or impurities. While many natural contaminants such as iron, sulfate, and manganese are not considered serious health hazards, they can give drinking water an unpleasant taste, odor, or color and be annoying and persistent problems and EPA has established secondary standards that can be used as guidance. Excessive levels of sodium, total dissolved solids, harness, can be an annoyance and impact appliances.  Several of the naturally occurring contaminants that commonly appear in well water are primary contaminants under the Safe Drinking Water Act and can be a health hazard at excessively high levels- nitrate, lead, arsenic, floride, and copper. The VCE Drinking Water Clinic will test for these.  

The goal of the Virginia Household Water Quality Program is to educate well owners, improve the water quality and protect the health of Virginians with private water supplies, such as wells, springs and cisterns. This all begins with testing and understanding your water and properly maintaining your water system. In 60 of Virginia’s 95 counties more than half the households rely on private wells, springs, and cisterns. In total there are more than 1,500,000 households in Virginia with private water supplies. Homeowners relying on private water supplies are responsible for all aspects of their water system’s management, but may lack the knowledge and resources to effectively and properly manage and maintain their wells and water systems. Until a big problem arises, many homeowners ignore their private water systems, but they should be routinely tested every 1-3 years (every year for bacteria). If there is a pregnant woman or infant in the home the water should be tested. If there is any change in the taste, appearance, odor of water or your system is serviced or repaired then water should be tested to confirm that no contaminants were introduced.  

In addition running  the drinking water clinics VCE has established the Virginia Master Well Owner Network (VAMWON), a group of Virginia Cooperative Extension educator/agents and screened volunteers trained in proper well construction and location, appropriate maintenance and protection of wells and springs, interpretation of water tests, and water treatment options. These educator/agents and volunteers form an excellent resource base for homeowners. If you are a private water system owner, consider contacting a Master Well Owner in your area if you cannot join us for the water clinic.

Dimock, Gasland and the EPA – Fracking and Water

Last Wednesday, July 25th 2012 the U.S. Environmental Protection Agency announced that it has completed its sampling of private drinking water wells in Dimock, Pa. Based on the outcome of that sampling, EPA has determined that the levels of contaminants present do not require additional action by the Agency, the water with the existing private well treatment systems is safe to drink. Regional Administrator, Shawn M. Garvin, said “The sampling and an evaluation of the particular circumstances at each home did not indicate levels of contaminants that would give EPA reason to take further action.  Throughout EPA's work in Dimock, the Agency has used the best available scientific data to provide clarity to Dimock residents and address their concerns about the safety of their drinking water.” The EPA’s news release is intended to end the story of Dimock, but bureaucratic speak is never really clear. So, let’s see if we can bring clarity and accuracy to the end of the story of Dimock, PA.  

The Safe Drinking Water Act, SDWA, which is how the EPA looks at water quality, defines a contaminant as “any physical, chemical, biological, or radiological substance or matter in water” (U.S. Code, 2002; 40 CFR 141.2). This is a very broad definition of contaminant includes every substance (including minerals) that may be found dissolved or suspended in water, everything but the water molecule itself. However, the SDWA only has MCLs and secondary standards for 91 contaminants. Groundwater aquifers are potentially vulnerable to a wide range of man-made and naturally occurring contaminants, including many that are not regulated in drinking water under the SDWA. The presence of a contaminant in water does not necessarily mean that there is a human-health concern. Whether a particular contaminant in water is potentially harmful to human health depends on the contaminant’s toxicity and concentration as well as other factors including the susceptibility of individuals, amount of water consumed, and duration of exposure. EPA did a final round of testing of the private wells in the Dimock area to make sure that the water from the drinking water wells was safe to consume and all identified contaminants were within the acceptable level as determined by a risk analysis. Most private well owners rarely test their well water quality and very few ever consider testing for the entire suit of contaminants regulated under the SDWA let alone the list of potential contaminants that EPA tested for here.

Dimock, Pennsylvania is located in Susquehanna County near the New York border, overlies the Marcellus Shale and was an early area that had been developed with hydraulic fracturing or fracking. Dimock had been made famous for its appearance in the Josh Fox movie Gasland.   In Dimock, Mr. Fox met families who demonstrated on camera how they were able to light their running tap water on fire due to the methane gas present in their wells. That was a rather spectacular display. Residents also claimed to be suffering from numerous health issues related to contamination of their well water. Methane is a simple asphyxiant that displaces oxygen from air. Methane released from water into an enclosed environment could cause serious symptoms. Exposure to low oxygen environments produces symptoms of central nervous depression, including nausea, headache, dizziness, confusion, fatigue and weakness. Even if there was no other contaminant of concern present in the water, the symptoms of central nervous depression could be very frightening.

Cabot began natural gas fracking in the Dimock area in 2008. On January 1, 2009, an explosion was reported in an outside, below-grade water well pit at a home located in Dimock. In Pennsylvania private drinking water wells are not regulated and are often the shallow, dug wells that are housed in a pit. The Pennsylvania Department of Environmental Protection (PADEP) collected samples from wells that provide drinking water to 13 homes located near the Cabot fracked gas wells, and these samples contained elevated levels of dissolved methane gas. (During the year the number of impacted homes would expand to 18 from 13.) The presence of dissolved methane and/or combustible gas was noted in the private wells within six months of completion of drilling of the Cabot  gas Wells and Cabot was presumed to be responsible for the pollution, pursuant to Section 208(c) of the PA Oil and Gas Act, 58 P.S. §601.208(c). None of the homes dependent on their private drinking water well had done any extensive testing of their water quality before Cabot began fracking in the area and all contaminants found (except for fecal coliform) are sometimes naturally present in groundwater. The two important questions raised were is the water safe to drink and did Cabot cause any change in the water quality by fracking in Dimock. PADEP presumed Cabot responsible and cited them for improper or insufficient cementing of the well casings. In addition there had been several other violations for improper storage of drilling mud, diesel spills, failure to maintain records and driller’s logs.

In November 2009 the PADEP entered into a consent agreement with Cabot for methane and metals removal systems for eighteen private wells in the Dimock area. The agreement was later revised several times. The revised agreement required Cabot to pay the impacted fam­i­lies set­tle­ments worth twice their prop­erty assessed val­ues, deposit the money into an escrow account and notify the residents that the money was available and to install a water treatment system (a filter or ion exchange system) in each impacted home. The agreement calls for each well owner to enter into the agreement with Cabot who was to install water treatment systems in their homes. Until the treatment systems were installed, Cabot was to provide delivered bottled water. There were no plans for confirmation testing to demonstrate the effectiveness of the filtration systems.  There were eighteen private wells that were part of the PADEP /Cabot agreement. By 2011 only six well owners had signed agreements and had water treatment systems installed in their homes. However, most of these were buying bottled water because they did not feel confident that the treatment systems were effective. Water treatment systems are often simple and unimpressive in appearance and verification sampling should have been performed.  Twelve of the private well owners had not signed the agreement Cabot and instead eleven (I could not trace the 12^th ) had filed a civil suit against the company. These owners were being provided delivered water by Cabot. On November 30, 2011, with the approval of the PADEP, Cabot ceased delivering water to these homes. PADEP agreed to stopping the water deliveries because there had been sufficient time for residents to sign the agreement and that a remedy for private well owners had been provided. Clearly, many of the homeowners were not satisfied with the remedy offered.

Very public protests took place aided by environmental groups and anti-fracking grass roots groups and  resulted in the EPA stepping in and reviewing all the data for the 18 wells. In their summery EPA notes that based on the maximum contaminant sampling results for the 18 wells sampled, levels of coliform bacteria, methane, ethylene glycol, bis (2-ethylhexyl) phthalate (DEHP), 2-methoxyethanoI aluminum were present.  Coliform bacteria were found in half the wells and typically indicate a pathway exists for disease causing bacteria to contaminant the water supply, though it . E. coli bacteria and fecal bacteria are a subset of coliform bacteria that only occur in animal and human waste and are a threat to human health. The level of coliform bacteria found in two of the wells was too high to measure. After reviewing all the sample data, information and residents’ concerns by the EPA and ATSDR (a part of the U.S. Department ofHealth and Human Services) the regulators identified a significant group of private wells in the nearby area that had not been tested and were not part of the existing PADEP /Cabot agreement. In addition, the level of concern and frustration of the residents who were party to the PADEP /Cabot agreement prompted EPA to temporarily supply water to four homes and perform follow up environmental monitoring and water sampling and have ATSDR perform a full public health evaluation on the data from the site area. Because many of these compounds affect the same organ systems, ATSDR used suitable methods to evaluate the potential for synergistic actions and the cumulative concentration of all substances, and dissolved combustible gases was considered to protect against the buildup of explosive gases in all wells in the area.

Between January and March of 2012 EPA collected 61 separate groundwater samples, 6 duplicates for quality control testing and performed188 analyses for each sample, in some instances the samples were filtered and retested. These samples covered the water supply to 64 homes, and two rounds of sampling at four wells where EPA was delivering temporary water supplies because prior sampling data found elevated levels of contaminants in those wells. EPA found an elevated level of manganese in untreated well water at one of the wells. Two homes that obtain their water from that well have water treatment systems that can reduce manganese to levels that according to the EPA do not present a health concern.

Many of the perceived problems with well water are caused by the presence of iron and manganese. Iron and manganese can give water an unpleasant taste, odor and color. Manganese causes brownish-black stains on household items washed with the water. In addition, water contaminated with iron and manganese often contains iron or manganese bacteria which feed on the minerals. These bacteria do not cause health problems, but can form a reddish brown or brownish black slime in toilet tanks and clog filters. Iron and manganese often occur together and are naturally occurring elements commonly found in groundwater in many parts of the country. At  levels naturally present in groundwater iron and manganese do not usually present a health hazard. However, their presence in well water can cause unpleasant taste, staining and accumulation of mineral solids that can clog water treatment equipment and plumbing. In addition, a persistent coliform (non-fecal) bacteria problem may be caused by iron bacteria. Under guidelines for public water supplies set by EPA, iron and manganese are considered secondary contaminants. The standard Secondary Maximum Contaminant Level (SMCL) for iron is 0.3 milligrams per liter (mg/L or ppm) and 0.05 mg/L for manganese. This level of iron and manganese are easily detected by taste, smell or appearance and thumbing through the results of the EPA sampling I saw manganese levels high enough to see and taste in drinking water.

In addition, to the elevated manganese, there were elevated levels of sodium not beyond what can occur naturally, elevated levels of arsenic not beyond what can naturally occur, but in at least one case significantly elevated over the other samples and above the SDWA MCL. Methane was present in several samples and can also be naturally occurring. Fecal coiform bacteria indicative of contamination from a septic system was present in one sample (that water is NOT safe) and coliform bacteria was present in several samples. Only one of their sodium levels was higher than mine which is naturally occurring, safe to drink and tastes good.   

ATSDR performed the risk analysis on the results. Overall during the sampling in Dimock, EPA found elevated arsenic, barium or manganese, all of which are also naturally occurring substances, in well water at five homes at levels that could present a health concern according to ATSDR. In all cases the private wells either now have or will have their own treatment systems that can reduce concentrations of those metals to acceptable levels at the tap.  EPA provided all the residents their sampling results and has no further plans to conduct additional drinking water sampling in Dimock or continue to provide drinking water. The water supply to these homes with their treatment systems is deemed to be safe by the EPA.

The bottom line is we really do not know definitively what impact if any Cabot caused to the groundwater. Cabot agreed that they failed to properly grout the gas wells and certainly they did not properly store and contain the fracking fluid. Publicized photos show jugs of dirty looking water reportedly from wells in the area and could be manganese and iron, fecal contamination, or dirt that entered the groundwater through surface infiltration of loosening of fines within the aquifer. EPA sampling is silent on water appearance. PADEP concluded that surface spills and shoddy construction practices by Cabot allowed natural gas from a shallow deposit above the Marcellus to drift into the drinking-water wells of residents. The non-quantified traces of chemicals that are sometimes used in fracking, and antifreeze and are common in fuel that had been reported in previous sampling were not found the EPA water samples. EPA found only naturally occurring heavy metals at levels of any concern.

For the past decade and a half, the US Geological Survey, USGS, has been studying groundwater quality in the United States. The presence of a contaminant in water does not necessarily mean that there is a human-health concern. Whether a particular contaminant in water is potentially harmful to human health depends on the contaminant’s toxicity and concentration in drinking water. Other factors include the susceptibility of individuals, amount of water consumed, and duration of exposure that is why the ATSDR performed their risk analysis.  In their survey testing of groundwater in the United States the USGS has found most man-made contaminants at both trace and concentrations exceeding human health screening levels or MCLs in groundwater samples from unconfined aquifers. These man-made contaminants originate at the surface and the unconsolidated aquifers provided little natural protection from surface infiltration. 

The shallow drinking water wells in Dimock make them particularly susceptible to contamination. The residents of Dimock did not regularly test their water quality historically. The bacterial concentrations found in early rounds of testing were troubling, though unlikely to have been caused by the fracking, but were indicative of susceptible and potentially poorly maintained or constructed wells. The fecal bacteria found in one well was a health hazard very unlikely to have been caused by fracking, but likely to be caused by a failing septic system. Prior studies of private well water in Pennsylvania have found that approximately one third of private wells test positive for total coliform bacteria (Swistock et al 2009). The highest incidence of coliform bacteria tends to occur with snow melts and rains that carry the bacteria from the surface, but can also occur with iron and manganese. Regularly testing your drinking water and maintaining any water treatment system in your home is an essential part of private well ownership. 

EPA Gathering Data on Emerging Contaminants in Our Drinking Water

The Safe Drinking Water Act, SDWA, is the Federal law that protects the public from drinking water contaminants that pose a known health concern. Only 91 contaminants are regulated by the Safe Drinking Water Act, yet according to the U.S. Environmental Protection Agency, EPA, more than 80,000 chemicals are used within the United States. Not every drinking water contaminant with health consequence gets regulated because they may not be widely present in source waters. And not every regulated contaminant has health consequence. Some contaminants are regulated to control taste and odor. Though the SDWA was adopted in 1974, it has had significant amendments in 1986 and 1996 that added explicit health goals, risk management approaches and methods of gathering data to allow the SDWA to continue to evolve and ensure the public water supply systems in the United States remains among the safest in the world.

The 1996 amendments to the SDWA created the Unregulated Contaminant Monitoring Rule, UCMR. This is the tool the EPA uses to determine if there are contaminants likely to pose a risk to the health of the nation. A contaminant is identified as being of a possible health concern in drinking water, by states, water systems, scientists or other sources.  Health information is collected and if deemed appropriate, occurrence and exposure information are collected using the UCMR data collection program for preliminary risk assessment then a determination is then made on whether there exists an opportunity to reduce public health risks by regulation and the contaminant is then added to the Drinking Water Contaminant Candidate List. The 1996 Safe Drinking Water Act (SDWA) amendments require that once every five years, EPA issue a new list of no more than 30 unregulated contaminants to be monitored by public water systems. The national sampling program provides the EPA with a scientifically valid database on the occurrence of these emerging contaminants in drinking water supplies.

The third Unregulated Contaminant Monitoring Rule list (UCMR 3) from the EPA was finalized and signed on April 16, 2012. The final version of the UCMR 3 requires public water systems, PWSs, serving more than 100,000 people to monitor their source and finished water for 30 contaminants using EPA approved analytical methods during 2013-2015 and provide the data to the EPA. Some smaller systems will be required to perform testing also, but EPA will pay for the analysis of all samples from systems serving 10,000 or fewer people and provide some technical assistance for sampling. In addition, EPA will select 800 representative PWSs serving 1,000 or fewer people that do not disinfect. These PWSs with wells that are located in areas of karst or fractured bedrock, will participate in monitoring for the 2 viruses during a 12-month period from January 2013 through December 2015. (This might be of particular interest to those in Raspberry Falls and Evergreen areas of Loudoun and Prince William Counties.) In all approximately 6,000 PWSs will collect data for a 12 months period creating a very powerful database so that overall exposure can be assessed.

EPA anticipates spending $20 million to subsidize the sampling and analysis in the small water systems, but the bulk of the sampling and analysis will be paid for by the large PWSs and ultimately by their rate payers. In this largest of systems, the anticipated cost of $50,000-$100,000 is not a significant burden, but on the mid-size systems the cost is noticeable. UCMR 2 cost Fairfax Water $50,000 in analysis and was entirely non-detect for all substances, but nationally, the nitrosamines were detected in 25% of the water systems tested. The levels detected ranged from 0.002-0.630 parts per billionwith an average of 0.009 ppb and might result in a regulatory standard for NDMAor all the nitrosamines. The only other UCMR 2 contaminants to appear at more than two of the 1,200 sample locations was the appearance of acetanilide pesticide degradation products in less than 5% of water systems testing. The levels found were up to 4 ppb and averaged less than 2 ppb. This is the only way EPA can gather data and determine if the population as a whole is being exposed to these substances and the levels of exposure. This is a primary data source for the EPA uses to make regulatory decisions for emerging contaminants. EPA has just opened nominations for the next list, UCMR 4. 

No actions have yet been taken as a result of the finding of UCMR 2, but N-nitorsodimethylamine, NDMA, may now be listed on the Drinking Water Contaminate Candidate List for potential regulatory action, but when I called the EPA to verify, they asked I submit my questions by email (which I did) and simply sent links to the Federal Register announcing the UCMR 3 which states “guide the

conduct of the Contaminant Candidate List (CCL) process and support the Administrator in making regulatory decisions for contaminants in the interest of protecting public health, as required under SDWA.” That was a frustrating waste of effort.  NDMA is a carcinogen known to be present in various foods and industrial products. The EPA hasestablished a 10(-6) cancer risk level for NDMA of 0.7 ng/l. NDMA has been found in the effluents of various water and wastewater plants, but its formation mechanism is not fully understood.  As I understand it from other sources there is consideration of regulation on all nitrosamines.

EPA selected the contaminants by first reviewing the agency’s lists of contaminants that need additional research to support future drinking water protections, from states monitoring programs and recommendations from public hearings and comments. The contaminants selected are known or anticipated to occur in public water systems or were selected based on current occurrence research and health-risk factors. Hexavalent chromium was the last addition, added to the list after comments to the proposed list strongly supported its inclusion. This final list includes 6 heavy metals, 7 volatile organic compounds, 7 hormones, 6 perflorinated compounds, 2 viruses, chlorate and 1,4 dioxane. The complete list can be viewed on the EPA website. These contaminants that are not regulated by the National Primary Drinking Water Regulations; are anticipated to occur at public water systems; and may warrant regulation under the Safe Drinking Water Act. The EPA is using the UCMR 3 to determine if these substances are present in drinking water supplies throughout the nation and what levels. In the past 15 years, concerns have been raised about the fate and effects of these emerging contaminants of concern being released into watersheds through upland runoff from both urban and agricultural lands, sewage discharges, and industrial releases. Many of these routes of release are almost constant at very low levels and without widespread sampling and appropriate analysis it is impossible to know what substances might be a real threat to human health.  

Chemicals are everywhere in our modern world, they exist in pharmaceuticals, household products, personal care products, plastics, pesticides, industrial chemicals, human and animal waste; they are in short, all around us. These chemicals include organics, inorganic, polymers, complex reaction products, and biological materials. The technology used for chemical analysis has advanced to the point that it is possible to detect and quantify nearly any compound known to human kind down to less than a nanogram per liter or parts per trillion (1/1,000,000,000,000). This enhanced analytical ability has allowed scientists to discover that trace levels of pharmaceuticals, potential endocrine disrupting compounds (EDC) and other emerging contaminants exist in surface water, have appeared in some groundwater and may to persist in the water through conventional and some advanced treatment trains to appear in our finished drinking water. What we don’t know is how prevalent these contaminants are and if these traces of compounds are a health concern.  

The emerging contaminants lack human health standards so the first step is to identify what substances are present at what levels in the environment. EPA has begun with water not only because there exists a way to mandate the data is collected on a national scale, but everyone drinks and bathes in water. Using the UCMR list to identify substances with widespread exposure through drinking water is the best way to prioritize contaminants. The next step would be to identify the acceptable human exposure level and need for regulation based on presence in the environment. Much of the environmental work in the past has been done on what are called the persistent priority pollutants, such as trace metals, pesticides, PCBs and PAHs, substances that persist in the environment.  Many of the emerging contaminants are environmentally non-persistent, but still may have health impacts. A non-persistent chemical breaks down and these breakdown products may be widely present in the environment.

The Fairfax County James J. Corbalis Jr. Water Treatment Plant

On Thursday, April 26, 2012 I went up to Fairfax County near Herndon to see the Corbalis Water Treatment Plant, the newer of the two Fairfax Water treatment plants and visit with Melissa Billman, the Water Quality Laboratory & Regulatory Compliance Manager and Jeanne Bailey, the Public Affairs Officer for Fairfax Water. Combined they have more than half a century experience in Water Treatment Pants and Compliance and were kind enough to take the time to share their knowledge and experience. Fairfax Water is one of the 25 largest water supply companies in the nation supplying drinking water to 1.7 million Virginians, 900,000 of whom reside in Fairfax County. Twenty percent of all Virginians who are served by public water get their water either directly or indirectly from Fairfax Water. Loudoun Water, Prince William Service Authority, Virginia American Water, the town of Herndon, Fort Belvoir, and Dulles airport all obtain some or all of their water from Fairfax Water.

The Corbalis Water Treatment Plant also houses the Fairfax Water Quality Laboratory built in 2005 and using the state-of-the-art gas chromatography and laboratory equipment that reminded me that I studied chemistry in the Stone Age. The Water Quality Laboratory tests 15,000 samples of water each year and tested for 67,000 parameters including 3,240 samples tested throughout the year for coliform bacteria alone. Each and every month 270 samples are tested for coliform bacteria for the Virginia Department of Health, VDH.  All this testing is done to ensure that the water delivered to  their customers meets or exceeds all regulatory standards and that the water supply delivered to their 1.7 million customers is the best possible drinking water with today’s knowledge and technology.

The Water Quality Laboratory monitors the water from the Potomac River and Occoquan Reservoir throughout the water treatment process and at various points in the distribution system for almost 300 parameters including the Federal Safe Drinking Water Act, SDWA primary and secondary contaminants for which there exist maximum contaminants limits and also for a list of emerging contaminants such as Endocrine Disrupting Compounds (EDCs), Pharmaceuticals, and Personal Care Products (PPCPs) that have been found in water nationally. Fairfax Water tests their source and treated waters for a list of 25 substances, hexavalent chromium and perchlorate have recently been added to the list. In 2011 Fairfax water found minuscule traces (parts per billion or parts per trillion) of 2,4-D, TCEP, DEET, Monensin, Simazine, Atrazine,hexavalent chromium and perchlorate in the finished water.

The technology used for chemical analysis has advanced to the point that it is possible to detect and quantify nearly any compound known to man down to less than a nanogram per liter or parts per trillion (1/1,000,000,000,000). The guiding principal of toxicology is that there is always a dose below which no response occurs or can be measured. So if the concentration of the contaminant was low enough there would be no toxic reaction and a trace amount of a substance does not necessarily represent a health risk. Fairfax Water as one of the largest (top 25) water utilities in the nation gathers and provides some data to federal and state regulators that may determine the future changes in the SDWA. In the meantime, research has shown that using the combination of ozone and granular activated carbon filtration that is used by Fairfax Water is very effective in removing broad categories of personal care products and pharmaceuticals as well as the more dangerous Cryptosporidium organism from the source water. Though, no method of filtration is 100% effective all the time.

  

After Melissa Billman showed us the laboratories and their equipment, Jeanne Bailey led the plant tour. Ms. Bailey once worked in this plant, starting when the plant was brand new and delivered 50 million gallons of water a day in 1982. Now the Corbalis Water Treatment Plant can deliver 225 million gallons of water a day and is planned to be expanded to 300 million gallons a day years from now when the fourth and final phase of the plant is finally built. The plant was conceived and planned to be built in phases.  The Corbalis plant is the newer of the two Fairfax Water Treatment Plants. Water from Fairfax Water is distributed through approximately 3,200 miles of water mains to the county’s homes and businesses. On average, Fairfax Water produces 160 million gallons of water per day from both the Corbalis plant and the Griffith plant. The combined total capacity of both plants is 345 million gallons/day. The system must be sized to deliver the peak demand on a 100 degree day when everyone is doing laundry and watering their lawns and everything else we do with water on hot summer days.  To ensure the continuation of water supply during droughts, Fairfax finalized a regional drought response plan in 2001 that included a low flow allocation agreement with the members of the Interstate Commission on the Potomac River Basin, ICPRB. In addition, Fairfax bought the rights to 14 billion gallons of water from the Jennings Randolph Reservoir. 

The Corbalis Plant draws its water from the Potomac River four and a half miles away. There are two water intakes-one near the shore and the other mid-stream, which ever intake has better water quality is the one that is used.  Bars and giant screens on the pipes are used to prevent the intake of trash, debris and fish. Potassium permanganate (KMnO4) is added to the water at the intake to control taste and odors, remove color, prevent biological growth within the water treatment plant, and remove iron and manganese. The raw water is then pumped to the Corbalis plant where is treated in a series of slow and elegantly simple steps to produce clean and clear drinking water. 

  

Once at the plant the water is pumped to the first of a series of water chambers where the pH is adjusted by adding either caustic soda or sulfuric acid and the primary coagulant, polyaluminum chloride. This coagulant is used to remove small particles of dirt suspended in the water by causing them to stick to one another aided by the coagulant polymer. The water moves from the first water chamber where it is well mixed through a series of chambers (which are really just a series of open rectangular water pools) with slower and slower mixing to allow the particles to coagulate into larger and larger particles until dirt floc is formed. Finally, the water arrives in the sedimentation basins that are not mixed at all and the floc is allowed to settle to the bottom of basins by gravity where they are removed. The floc is thickened by the addition of a polymer, filtered, dewatered by pressure and ultimately used as a lovely agricultural soil amendment.

The next step in the water treatment process is ozonation, the infusing of the water with ozone gas and the first of two disinfection steps. This step was added at the Corbalis plant in 2000 and used this way is still very much leading edge in water treatment technology. Ozone is highly effective in eliminating the Cryptosporidium bacteria and other naturally occurring microorganisms present in water. Unlike ultraviolet and chlorine disinfection systems, there is no re-growth of microbes after ozonation. This step improves the taste and smell of the water. Ozonation also reduces the formation of trihalomethanes (chlorine breakdown products) because of the reduction of organic materials in the water before chlorination. Fairfax water converts liquid oxygen to ozone by an electrical discharge field created within a series of tanks. Viewed just right, you should be able to see the purple corona during the process, but I did not see it.

Ozonation is followed by filtration through granular activated carbon and sand. One cup of GAC has the surface area of about 25 football fields (1,300,000 square feet). Billions of pores in GAC absorb the organic substances removing them from the water and is very effective in removing biological and physical impurities that occur in broad categories of personal care products and pharmaceuticals as well as the more dangerous Cryptosporidium organisms from the water. Slow flow through the filter tanks improves the effectiveness of the filtration. The filter water wash, all runoff from the plant and the water from the dewatering process are reclaimed and returned to the raw water control chamber.

The final steps in the water treatment process is the second disinfection, fluoridation and the addition of a ammonium hydroxide to adjust the pH slightly to prevent corrosion of piping and fixtures in customer  homes to prevent the leaching of lead into water. Nine months of the year Fairfax Water uses chloramine as the final disinfection step. However, during April, May and June of every year Fairfax Water flushes the entire 3,200 miles of water main and uses chlorine during that time to disinfect the delivery network. Flushing the water system entails sending a rapid flow of water through the water mains. As part of the flushing program, fire hydrants and valves are checked and cleaned. Flushing of the water distribution system is performed to remove sediment in pipes and helps to keep fresh and clear water throughout the distribution system. Chlorine is used as the disinfectant during this time so that after the system is flushed, a chlorine residual is maintained in the distribution system to provide a persistent disinfectant to prevent the re-contamination of water before your water tap.

Building the plant in phases has allowed Fairfax water to modify their water treatment process and stay in the forefront of water treatment. Yet, Fairfax Water delivers water to their customers significantly below the national average cost of water, has the lowest retail water rates in the region and has a repair and replacement program that responds not only to the water main breaks, but is designed to replace the entire water supply and distribution system ever 75 years. Many thanks to Melissa and Jeanne for their time and a very interesting afternoon.