The Coastal Plain Aquifer

 

The Northern Atlantic Coastal Plain aquifer system consists of six regional aquifers and extends from Raritan Bay, N.J. to the North Carolina-South Carolina State line. The crystalline rocks of the Piedmont Physiographic Province at the Fall Line mark the western limit of the aquifer. The eastern limit of the aquifer system is, for all practical purposes, the shoreline. The northern part of the Atlantic Coastal Plain is underlain by a wedge-shaped mass of semi-consolidated to unconsolidated sediments that thickens toward the ocean and is topped by a layer of crystalline rock.

The thickness of the sediments vary. At the New Jersey coastline they are about 4,000 feet, but the sediments reach as much as 8,000 feet along the coast of Maryland and 10,000 feet along the coast of North Carolina. The sediments consist of lenses and layers of clay, silt, and sand, with minor amounts of lignite, gravel, and limestone. The sand, gravel, and limestone make up the water bearing aquifers; some are traceable over long distances, whereas others are only local.

The aquifers are separated by confining units of clay, silt,and silty or clayey sand. Although water moves more readily through the aquifers than through the confining units, water does leak very slowly through the confining units, especially where they are thin or where they contain sand; the aquifers, therefore, are hydraulically interconnected to some degree.

A series of clay and silt confining layers separate the regional aquifers that are used for water supply (Masterson and others, 2015). Recharge enters the aquifer mostly from the outcrop areas in the landward part of the aquifer system, but some limited recharge comes from downward leakage through confining units.

The surficial aquifer is the uppermost aquifer in the aquifer system.  This aquifer consists of unconsolidated, locally gravelly sand, mostly of Quaternary age. Although a thin blanket of unconsolidated sediments makes up the uppermost Coastal Plain beds over wide areas, these sediments generally yield small volumes of water to rural and domestic wells. Water in the surficial aquifer is especially susceptible to contamination by human activities and saltwater intrusion. 

The Chesapeake aquifer underlies the surficial aquifer in most places, but the two aquifers are separated by a clayey confining unit that significantly slows the downward movement of groundwater, though does not prevent it. The Chesapeake aquifer consists mostly of sand beds of Miocene age.

The Piney Point-Castle Hayne aquifers and the Potomac-Magothy aquifers (which include Mago[1]thy, Potomac-Patapsco, and Potomac-Patuxent aquifers) are aquifers in the Northern Atlantic Coastal Plain aquifer system that are the primary sources of groundwater for public supply (Masterson and others, 2015). The Potomac aquifer in Virginia comprises part of the regional Potomac aquifer system, which also includes the Potomac-Patapsco aquifer and Potomac-Patuxent aquifer in Maryland, Delaware and New Jersey.

The Potomac aquifer is a confined aquifer that once formed artesian wells prior to being de-pressurized. The Potomac aquifer is several thousand feet thick for much of the Coastal Plain and contains hundreds of trillions of gallons of pressurized water. Unfortunately, what once seemed like a vast never-ending resource is being overused. In Virginia approximately 155million gallons of groundwater is pumped from the Potomac aquifer each and everyday.

The first hint of a problem was a drastic reduction the pressure of the confined water. Water no longer rose to the surface without lift pumps. Then the groundwater level began to fall. Deeper wells were needed to access water. This was followed by aquifer compaction – and now, land subsidence, saltwater intrusion and increased vulnerability to sea level rise.

This groundwater provides much of the drinking water in the Hampton Roads area. There is only Beaverdam Lake reservoir on the Coastal Plain of the Middle Peninsula that supplies drinking water, and no drinking water reservoirs on the Northern Neck. North of the York River almost all of the public and private drinking water comes from groundwater.  The rate of groundwater withdrawal from the Potomac Aquifer is currently unsustainable.

Groundwater in the Coastal Plain region in eastern Virginia is being used up. This has been confirmed by measurements of groundwater levels, modeling of the aquifer system by the U.S. Geological Survey (USGS) and measurements of changes in gravity by the National Aeronautics Space Administration (NASA). Reducing water use in the region to a sustainable level for the Potomac Aquifer would be economically devastating and quite frankly, an impossible task. You can’t take away water without a fight. We are left with either adding reservoirs and surface water systems or utilizing the water storage capacity of the groundwater aquifer. Like many parts of the country and Northern Virginia, the Hampton Roads area has turned their sights on reusing wastewater to supplement the drinking water supply. Their plan is to utilize the existing storage in the groundwater system.  

For 40 years Los Angeles County has recycled the water from wastewater treatments plants. This water from both secondary and tertiary treated wastewater is discharged into spreading basins on the surface to recharge groundwater. Groundwater recharge can be done by surface spreading or direct injection wells. It has long been know that soil filtration improves water quality and soil column studies with secondary effluent from wastewater treatment has shown dissolved organic carbon removal of about half by percolation through 20 feet of various soil types. However, the 40 years experience has found trace contaminants from disinfection by products in the groundwater.

Recharging an aquifer has lower capital costs than dam and reservoir construction, but carries risks and challenges.. The first challenge is geologic. The predominant geology of this area of Virginia makes the usual methods of artificial recharge- spreading basins almost impossible. Without using injection wells, to deliver water  directly into an aquifer it would not be practical. Artificially recharged water must first move through the clay zone and the only effective method is to use a recharging well. This method has risks, big risks. We are potentially introducing trace contaminants, precursors of disinfection byproducts, trace Pharmaceuticals and personal care products and many other unknow contaminants  from our modern world into our groundwater aquifers. Before we use reclaimed wastewater to recharge the groundwater aquifer to augment supply, we need to fully understand what contaminants (and emerging contaminants) survive treatment and are carried in the wastewater to the aquifer.

Enter the Sustainable Water Initiative for Tomorrow (SWIFT) project. It proposes to replenish the Potomac aquifer, eastern Virginia’s primary groundwater supply, with purified water. This purified water would be treated to be compatible with the existing water in the aquifer to ensure seamless integration into the system and introduced by recharge wells drilled at seven of the 13 Hampton Roads service District wastewater treatment plant sites. Recharge wells store water for future use by placing it deep underground into formations below the shallow soil layer.

This is a great concept, but the question remains is it possible to do safely in practice in Virginia? Currently, wastewater (sewage) travels through multiple levels of treatment at Hampton Roads Service District, HRSD’s, 13 wastewater treatment plants to ensure it meets regulatory discharge levels of particular contaminants that are measured and are protective of aquatic life and public health. With the SWIFT project, the treated wastewater will undergo additional treatment procedures in the Advanced Water Treatment Process to treat it even further in order to meet stringent drinking water standards. Right now, at the research center in Suffolk, Virginia a million gallons of day of treated wastewater is being further treated to meet the higher drinking water standards and pH and oxygen levels of the aquifer and is injected at low pressure to a well with open slotting between 500 and 1,400 feet below grade into the aquifer.

The groundwater aquifer serves to dilute the trace contaminants that survive the treatment plant, but we need to be honest and informed about what we are putting into or leaving in what is ultimately our drinking water supply. The water of the Potomac Aquifer has been protected for a millennium from man’s arrogance and lack of knowledge. Now we are injecting what we believe to be clean water directly into this water body. With plans to inject a million gallons of reclaimed water a day.

Maybe we should pump this water directly into the drinking water distribution system in Hampton Roads for a few decades to make sure there are no unexpected consequences before we pump a million gallons a day into the aquifer. The solution to pollution may not be dilution.

Camp Lejeune

Prince William County is home of Quantico. For months a TV commercial has been playing where a lawyers are seeking victims to represent to bring a Camp Lejeune lawsuit for injuries and deaths from toxic chemicals and water contamination in the water supply at the marine corp base. In case you don't know what that is about, the story began in 1980.

At that time when in compliance with brand new regulations from the young U.S. Environmental Protection Agency, PA, the base began testing the water for trihalomehtanes. That same year, a laboratory from the U.S. Army Environmental Hygiene Agency began finding contamination from halogenated hydrocarbons in the water. In March 1981 one of the lab's reports, which was delivered to U.S. Marine officials, informed them that the drinking water was highly contaminated with other chlorinated hydrocarbons (solvents).

Possible sources of the contamination were identified as solvents from a nearby, off-base dry cleaning company, from on-base units using solvent to degrease motors and other military equipment, and leaks from underground fuel storage tanks.

In 1982 the USMC hired a private company, Grainger Laboratories, to examine the problem. They provided the base commander with a report showing that the drinking water wells supplying water for the base were contaminated with PCE and TCE, the solvents used in drycleaning and equipment maintenance. The contractor delivered repeated warnings to base officials and was fired after delivering written warnings in December 1982, March 1983, and September 1983.

In a spring 1983 report to the EPA, Lejeune officials stated that there were no environmental problems at the base- they knowingly lied. In June 1983, North Carolina's water supply agency asked Lejeune officials for the lab’s reports on the water testing. Marine officials declined to provide the reports to the state agency.

In July 1984, a different company contracted by the U.S. EPA under the Superfund review of Lejeune and other military sites found benzene in the base's water, along with PCE and TCE. Marine officials shut down one of the contaminated wells at Camp Legeune in November 1984 and the others in early 1985. The Marines notified North Carolina of the contamination in December 1984. At this time the Marines did not disclose that benzene had been discovered in the water and stated to the media that the EPA did not mandate unacceptable levels of PCE and TCE.

Ultimately, it all came out as it always does. People were hurt, exposed to chemical contamination over an additional period of years after the contamination was discovered while the Camp Lejeune denied the existence of the problem. EPA did develop limits for PCE and TCE as they are now doing with other chemicals (for example PFAS’s). The water contamination probable began in the 1950’s long before anyone was aware of it, but continued on for decades even after the problem was known by some. That is a sin.

We are far more aware of the potential for contamination now and are aware that new concerns do emerge as we learn more. People, I am afraid do not change. The current analogy for the data centers in Prince William County is that they will impact the Occoquan Watershed which is the drinking water supply for over a million people and the most urbanized watershed in the nation. No significant change should take place without performing careful study first. That is not the plan of Prince William County. 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 and quantity 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 all of us, the residents who remain- not those who get the windfall from the sale of their land and dash off with their millions. However, Prince William County has chosen to move ahead without performing any studies first. That is malfeasance. Shana tova.

Dominion Power Agrees to More Monitoring Wells at Possum Point

Last week Dominion Power agreed to install additional groundwater monitoring wells and conduct bi-weekly monitoring of the new wells. When these wells are installed it will bring the total number of monitoring wells at Possum Point to 24 and provide enhanced monitoring and protection for Quantico Creek, the upstream neighbors and the Potomac River from the dewatering of the coal ash ponds at Dominion’s Possum Point Power Station.

If you recall, Dominion Power has been moving forward with a plan to “close in place” 3.7 million cubic yards of coal ash under the finalized U.S. EPA Coal Ash regulation. The plan for Possum Point is to consolidate all of the on-site coal ash into one impoundment. There is estimated to be 3.7 million cubic yards of coal ash. Dominion has collected more than 1 million cubic yards of ash from four smaller ponds, put them in a 120-acre pond that already contains 2.6 million cubic yards of coal ash that they have begun to dewater. The plan calls for the pond to be capped with an impermeable membrane to prevent future infiltration of rain.

These coal ash ponds have been open to the elements and taking on water for decades. Trace contaminants and metals in the coal ash may have already leached into the groundwater, Quantico Creek and Potomac. The State Water Control Board and Virginia Department of Environmental Quality (DEQ) are the regulating agencies that oversee the dewatering of the ponds, though the U.S. EPA maintains authority to review applications and permits for "major" dischargers, a distinction based on discharge quantity and content. In January 2016 DEQ and the Water Control Board approved the modifications to Dominion’s Virginia Pollutant Discharge Elimination System (VPDES) Permit allowing the treatment and subsequent discharge of the coal ash waters to Quantico Creek, which flows into the Potomac River.

The Virginia Department of Environmental Quality (DEQ) issued a discharge permit in 2013 authorizing Dominion Power to discharge wastewater from coal ash ponds D and E at Possum Point through a designated outfall. On August 18, 2015, Dominion Power applied for and received a permit modification from DEQ seeking authorization to drain wastewater stored in ash pond D into either a tributary of Quantico Creek or Quantico Creek directly. This wastewater includes high levels of arsenic (960 µg/L, as compared to the EPA freshwater standard of 150 µg/L) and other metals. DEQ staff estimated that pond D holds approximately 150 to 200 million gallons of wastewater, and estimated that dewatering of coal ash pond D will take two years.

On January 19, 2016, DEQ issued a final modified permit for the Possum Point Power Station authorizing the release of wastewater from coal ash pond D into a tributary of Quantico Creek or Quantico Creek directly and authorizing the discharge from the toe drain. This was followed by The Potomac Riverkeepers (represented by the Southern Environmental Law Center) and Prince William County Board of Supervisors filed appeals to the permit.

Last spring an agreement was negotiated between Dominion Power and the Prince William County Board of Supervisors. The county would withdraw their appeal and Dominion Power agreed to reduce contaminant levels in the discharged water and independent testing of the levels:

• ​Dominion agrees to provide advanced treatment of all water from the coal ash ponds prior to discharge, regardless of whether this treatment level is needed to meet the required VPDES Permit levels.
• Dominion agrees to take additional hourly samples, and if any of the samples exceed more stringent triggers for certain elements (arsenic, selenium, lead, copper, antimony, and thallium), Dominion agrees to provide an additional enhanced treatment step, thus assuring the final effluent concentrations will be considerably lower than required by the VPDES Permit. 
• Dominion will only use a State accredited third-party independent laboratory for its VPDES Permit-required sampling and testing.
• Dominion will implement Standard Operating Procedures and Quality Assurance/Quality Control protocols. 
• Dominion will regularly post on a publically accessible website all permit-required test results for public review.
• Dominion and the County will work collaboratively to coordinate on solid waste permitting during the next phase of the closure of the inactive coal ash ponds to ensure that the Board’s and Dominion’s commitments to groundwater quality and environmental protection continue to be met.
• Dominion will reimburse the County for its costs of outside technical consultation services regarding this state and federal regulatory matter pertaining to the water discharge and the solid waste permit application review. As such, the County and its citizens will not be responsible for these costs. 

Three weeks ago, the Potomac Riverkeeper Network argued to have the courts set aside the modified VPDES permit for Possum Point and remand the matter to the State Water Control Board and DEQ . The court failed to set aside the permit, but the court declined. Nonetheless, DEQ requested the additional monitoring wells. DEQ’s media spokesperson, Bill Hayden, said the request is part of the normal solid waste permitting process. Since Dominion Power has reported elevated groundwater concentrations of certain heavy metals associated with coal ash, additional monitoring wells were necessary to identify the extent of the contamination.

Possum Point Power Station is located in Dumfries Virginia in the eastern part of Prince William County that borders the Potomac River and the Quantico Creek. Dominion Virginia Power has not burned coal at Possum Point for 13 years and is unlikely to burn coal to generate power in the future. Possum Point is downstream from nearby drinking water supplies and is unlikely to impact local residents beyond what has already taken place over the decades. Though, let me clearly state that when coal ash is stored in ponds without proper and effective liners, harmful pollutants from coal ash can leach or dissolve into the water and move into the groundwater, streams, rivers and bay.
Dominion’s monitoring has shown that the coal ash ponds at Possum Point have leaked cadmium, zinc, and other pollutants into the on-site groundwater, but no off-site monitirng has been carried on before now so the extent of the environmental impact is not known.

The Potomac Riverkeepers are pushing to have the coal ash waste removed from the site and disposed of in a lined landfill far from any surface waterways. I disagree, because I am concerned about protecting our groundwater as well as our surface water. I do not believe in hauling one environmental problem to another location to become a second environmental problem. Closing the coal ash on site when properly done is the best solution. A safe closure requires a fully lined pond, ongoing monitoring and maintenance that is best accomplished at an operating and regulated plant rather than at a remote cap and leave it location. All physical barriers fail over time this is addressed by monitoring and maintaining the systems.

Hexavalent Chromium and Possum Point

When Dominion Power agreed last week to provide enhanced monitoring and protection for Quantico Creek and the Potomac River from the dewatering of the coal ash ponds at Dominion’s Possum Point Power Station they promised to perform enhanced monitoring for arsenic, selenium, lead, copper, antimony, and thallium. They did not mention hexavalent chromium. The reason is that hexavalent chromium is not regulated in Virginia or on a federal level. In September, 2010, EPA released a draft of the scientific human health assessment (Toxicological Review of Hexavalent Chromium) for public comment and external peer review, but has yet to finish the review, water issues are lower on their priority list.

Only a small fraction of the 80,000-100,000 potential drinking water contaminants are regulated. The EPA only regulates chemicals that are found to be prevalent in large water systems, are dangerous to public health and can be cost effectively removed. Currently, the EPA is analyzing data collected in its UCMR3 national drinking water monitoring program during 2013-2015 to understand the prevalence of chromium and hexavalent chromium exposure in large drinking water systems in the United States. However, hexavalent chromium is more likely to occur in groundwater and is quite persistent. Though hexavalent chromium can occur naturally, there are locations where chromium compounds have been released to the environment and groundwater in particular through leakage of waste storage ponds and improper industrial disposal practices.

Though Possum Point is downstream from nearby drinking water supplies; however, the current level of impact needs to be investigated and monitored for the 24 nearby private wells. Dominion’s enhanced monitoring should include testing of groundwater and the 24 nearby drinking water wells for hexavalent chromium to determine the extent of impact if any from the decades storage of the coal ash on site. The Prince William County Health District is taking the lead in providing water analysis for those homeowners and should include analysis for hexavalent chromium. There has been no testing of the 24 nearby drinking water wells for hexavalent chromium, but hexavalent chromium can be measured at levels as low as 0.02 ug/L by ion chromatography using a modified version of EPA Method 218.6 or EPA Method 218.7. However, at this time the homeowner will have to bear the cost of the analysis.

The owners of those nearby wells should contact the Department of Health and remember Hinkely, California located in the Mojave Desert. The groundwater in Hinkley became contaminated with hexavalent chromium from the compressor plant operated by Pacific Gas and Electric (PG&E). You may have heard of Hinkely or hexavalent chromium because of the movie “Erin Brockovich.”

In 1993, a legal clerk named Erin Brockovich investigated an elevated cluster of cancer in Hinkley that were linked to hexavalent chromium. Average hexavalent chromium levels in Hinkley were recorded as 1.19 parts per billion (ppb) with an estimated peak of 20 ppb. The PG&E Compressor Station averaged 7.8 ppb and peaks at 31.8 ppb based on the PG&E Background Study.

Though the U.S. Environmental Protection Agency (EPA) regulatory limit of total chromium at 100 ppb, and the EPA does not regulate hexavalent chromium at this time, it would be a tragedy not to verify that the nearby drinking water wells have not been impacted by the decades of coal ash storage at Possum Point. The California maximum contaminant level (MCL) for hexavalent chromium was lowered in 2014 to 0.01 ppb in drinking water. Hexavalent chromium in drinking water is not regulated in Virginia, only total chromium.

Chromium is an element that is found naturally in coal in what is called the trivalent oxidation state, Cr(III). Chromium exists in nature as either a component in clay minerals such as illite or chlorite, or as its oxidized components; small-particle chromium oxide (Cr2O3) or oxyhydroxide (CrOOH) carbonaceous components of coal, or more rarely as chromite (FeCr2O4), as a result of special geology. Chromium is a metallic element found in rocks, soils, plants, and animals.

Cr(III) is relatively non-hazardous to humans and is in fact an essential nutrient. Chromium in coal is not considered a serious health risk. However, during commercial coal combustion, coal is burned with excess air to raise heat to generate steam for turbines that produce electricity. In the process, significant quantities of ash are created from the incombustible inorganic components in coal. That ash can contain not only hexavalent chromium, but also arsenic, selenium, lead, copper, antimony, and thallium. Furthermore, there is the potential for greatly increasing the health risk associated with chromium because not only can its concentration in the ash be increased by up to 10 times compared to that in the original coal, but Cr(III) can also be oxidized during coal combustion to form Cr(VI), which poses a much greater threat to public health.

Hexavalent chromium is commonly referred to as: chromium 6, chromium VI, Cr(VI), Cr+6, or hex chrome. Hexavalent chromium in the form of chromates is very soluble and, because of the six available electrons it has a high oxidizing capability, and can have severe adverse effects on the human body, including cancerous tumor formation and gene damage. Research by the National Toxicology Program (NTP) has found that hexavalent chromium causes cancer in laboratory animals following oral ingestion at high doses (NTP, 2008). California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) analyzed data collected from China that found increased rates of stomach cancer in people who were exposed to very high levels of hexavalent chromium in drinking water (OEHHA, 2010).

Hexavalent chromium can be measured at levels as low as 0.02 ug/L by ion chromatography using a modified version of EPA Method 218.6 or EPA Method 218.7. Though I believe that Dominion Power should pay for the analysis, and the Prince William Health District should test to make sure that all residents of Prince William County have groundwater that is safe to drink, test your well for piece of mind.

Micro Pollutants from Septic Systems

Traces of pharmaceuticals, hormones and personal care products associated with everyday life in the United States are finding their way into groundwater through septic systems and these micro pollutants can find their way into drinking water supplies. This is exactly what is happening in New York and New England, according a recently published study by the U.S. Geological Survey (USGS). The paper, “Concentrations of hormones, pharmaceuticals and other micropollutants in groundwater affected by septic systems in New England and New York” by Patrick J. Phillips, Irene J. Fisher, et. al. details the findings at two different locations that were studied, one in New England and the other on Fire Island in New York.

This study was the first to be published that used a new highly sensitive analytical method developed by the USGS National Water Quality Laboratory that identifies more than 100 pharmaceuticals, pharmaceutical degradates and related contaminants in trace concentrations. This method has detection limits for many compounds in the low nanogram/liter (that is about one thousandth of a part per billion) range, and significantly advances the abilities of the USGS to assess the presence and concentrations of pharmaceuticals in the environment.

The two sites were chosen because high nitrate concentrations in groundwater samples down gradient of these septic systems begged the question of what other chemicals might also be present. Though nitrate can contaminate groundwater from fertilizer use; leaking from septic tanks, sewage and erosion of natural deposits, increased nitrate concentration is usually a sign of improperly operated or failing septic systems and is an indication that septic system waste is contaminating groundwater. The MCL for nitrate is 10 mg/L and easily tested for. The NO3 dissolves and moves easily through soil. Due to plant uptake, there is a seasonal variation, and testing in the spring will usually produce the highest levels of nitrate. Elevated nitrate usually indicates contamination from septic tanks as it did here. What is important about this study is that the USGS scientists also found traces of other chemicals in the groundwater and demonstrated that these pharmaceuticals and related contaminants do not just disappear, but are spreading through groundwater into the environment.

The USGS scientists looking for micropollutants in groundwater collected samples down gradient of septic systems. The scientists tested for items such as pharmaceuticals, personal care products, and plasticizer compounds used in plastics. In New England a series of existing down gradient groundwater wells and wells installed to monitor the leach field were used to collect samples to measure the effect of a single large septic system that serves a nursing home with 65 patient beds and staff. Samples were collected from below the septic system leach field in addition to samples from wells down gradient of the septic system. The USGS scientists found numerous prescription drugs in the groundwater samples, such as anesthetics; a muscle relaxant; an antifungal; an antiepileptic; an antibiotic; a sleep aid; and also a floor cleaner. Total concentrations for these compounds generally ranged from 1 to over 20μg/L in the groundwater samples. High tris(2-butoxyethyl phosphate) plasticizer concentrations in wells beneath and down gradient of the leach beds (>20μg/L) were thought to reflect the presence of this compound in cleaning agents used at the nursing home.

On Fire Island in New York, groundwater samples were collected from an area of dense summer populations (5 dwellings/acre). The Fire Island septic systems have minimal treatment of wastewater (they are essentially tank only systems) before mixing with shallow groundwater that moves towards a large, estuary where a decline in fisheries and shellfish along with a higher ratio of female-to-male fish had been reported.

Shallow groundwater samples collected along the beach of this estuary down gradient of the septic systems were found to have hormones; detergent degradation products; galaxolide, a fragrance found in various products; insect repellent; sunscreen additives; floor cleaner; and two pharmaceuticals (lidocaine, a local anesthetic; and carbamazepine, an anti-convulsant and mood stabilizing drug). The highest micropollutant concentrations for the Fire Island study found in one of the shoreline wells that had personal care/domestic use, pharmaceutical, and plasticizer concentrations ranging from 0.4 to 5.7μg/L.

Most micropollutant concentrations increased with increasing total nitrogen concentrations for the shoreline well samples. The USGS scientists draw narrow conclusions stating that “these findings suggest that septic systems serving institutional settings and densely populated areas in coastal settings may be locally important sources of micropollutants to adjacent aquifer and marine systems.” The potential for measurable groundwater contamination and environmental impact from septic systems clearly places these systems within the expanded EPA definition of “navigable waters of the United States” and makes regulatory action possible if not likely.

Septic systems are common in rural areas and those lacking connection to larger scale sewage treatment plants. Septic systems consist of holding tank where raw sewage collects and separates into a sludge (solid) and liquid effluent. The liquid effluent either leaches directly into the surrounding soil or goes into a leach field for final treatment by the soil. The liquid effluent from septic systems ultimately moves into the groundwater. There are also alternative septic systems that have a secondary treatment system (be it a secondary aerobic tank or other treatment media) to remove pollutants. Though more than 30% of households are served by onsite septic systems, a significant numbers are quite old and many are not properly operated or maintained. Proper maintenance of septic systems (both traditional and alternative) is essential for protection of public health and local water resources. With new more sensitive testing methods it is possible to measure the impact of these systems on groundwater supplies and the environment. However, a simple annual nitrate measurement would indicate a problem and can be used as a proxy for the more expensive tests.

The article discussed:

Concentrations of hormones, pharmaceuticals and other micropollutants in groundwater affected by septic systems in New England and New York, Science of The Total Environment, Volume 512-513, Issue null, Pages 43-54,P.J. Phillips, C. Schubert, D. Argue, I. Fisher, E.T. Furlong, W. Foreman, J. Gray, A. Chalmers.

What’s EPA Doing about Fracking?

EPA will be holding a webinar on their fracking studies that includes research approach, status, and next steps if you are interested. The webinar will be presented on two different days, Thursday, January 3rd and Friday, January 4th 2013. Jeanne Briskin, Hydraulic Fracturing Research Coordinator, Office of Science Policy, Office of Research and Development will be the instructor and the webinars are: on January 3, 2013, 2:00 PM - 3:00 PM, EST and January 4, 2013, 12:00 PM - 1:00 PM, EST. Just click through on the links and sign up.

The United States has vast reserves of natural gas within shale and rock formations. During the past decade, extracting that gas has become commercially viable as a result of the advances made in horizontal drilling and hydraulic fracturing (fracking) techniques. With the rapid increase in fracking has come the increase in concerns about its potential impacts on drinking water. In response to public concern ignited by the film Gasland and protests by anti-fracking groups, the US House of Representatives requested that the US Environmental Protection Agency (EPA) examine the relationship between fracking and drinking water resources in 2009. In 2011, the EPA began a series of research projects into the impacts and potential impacts of fracking on water. Also, in April 2012 EPA released the first federal air rules for natural gas wells that are hydraulically fractured, specificallyvrequiring operators of new fractured natural gas wells to use “green completion,” which is a series of technologies and practices to capture natural gas and other volatile substance that might otherwise escape the well during the completion period when most volatile release takes place.

Hydraulic fracturing has its own water cycle and involves the pressurized injection of fluids commonly made up of mostly water and chemical additives into a geologic formation. The pressure used exceeds the rock strength and the fluid opens or enlarges fractures in the rock. As the formation is fractured, a “propping agent,” such as sand or ceramic beads, is pumped into the fractures to keep them from closing as the pumping pressure is released. The fracturing fluids (water and chemical additives) are partially recovered and returned to the surface. Natural gas will flow from pores and fractures in the rock into the wells allowing for enhanced access to the methane reserve. Two to five million gallons of water are typically necessary to frack one horizontal well in a shale formation. Water used for fracturing fluids is acquired from surface water or groundwater in the local area. Wastewaters from the hydraulic fracturing process (flowback or water produced in the well) may be disposed in several ways. The water that flows back after fracturing may be returned underground using injection well, discharged to surface waters after treatment to remove contaminants, or applied to land surfaces. Not all fracturing fluids injected into the geologic formation during hydraulic fracturing are recovered. The EPA estimates that the fluids recovered range from 15-80% of the volume injected depending on the site. The long term fate of any residual fluid has not been studied.  

Each stage of the fracking water cycle is a potential area for impact to drinking water supplies especially from human error and irresponsibly and improperly handling chemicals and contaminated water and poorly managing and protecting our water resources.  The steps in the fracking water cycle are:

Water acquisition. Chemical mixing. Pressurized Well injection. Flowback and produced water (collectively referred to as “hydraulic fracturing wastewater”) recovery. Wastewater treatment and disposal. Geology, hydrology and human behavior will produce vastly different outcomes for different regions of the county and different gas companies.

from US EPA

EPA is engaged in a number of research projects that will be the basis of their actions and future regulations for oil and gas operations. Whether the EPA will regulate oil and gas exploration nationally or leave the oversight in the hands of the states is an open question. There is an argument that water resources and geology are very local phenomena and cannot be generalized over the nation and that hydraulic fracturing should remain under local oversight. The 2005 energy law exempts fracking from the Safe Drinking Water Act based on the 2004 EPA study “Evaluation of Impacts to Underground Sources of Drinking Water by Hydraulic Fracturing of Coalbed Methane Reservoirs.” In that report EPA reviewed 11 major coal basins mined for coalbed methane and saw no conclusive evidence that water quality degradation on underground drinking water supplies had occurred as a direct result of the injection of hydraulic fracturing fluids, but fracking of coalbeds generally involves a fraction of the water used in hydraulic fracking of shale gas.

The current fracking projects are a series of studies. Existing Data from multiple sources have been obtained for review and analysis. Well construction and hydraulic fracturing records provided by well drillers are being reviewed for 333 oil and gas wells across the United States; data within these records are being examined to assess the effectiveness of current well construction practices at containing gases and liquids before, during, and after hydraulic fracturing. In addition information on the chemicals and practices used in hydraulic fracturing has been collected from nine companies that hydraulically fractured a total of 24,925 wells between September 2009 and October 2010. Data on causes and volumes of spills of hydraulic fracturing fluids and wastewater are being collected and reviewed from state spill databases.

Computer models are being developed to identify conditions that may lead to impacts on drinking water resources from hydraulic fracturing. The EPA has created hypothetical scenarios for  water acquisition, well injection, and wastewater treatment and waste disposal stages of the water cycle that they hope to have the models evaluate. Computer models are also being used to explore the possibility of subsurface gas and fluid migration from deep shale formations to overlying aquifers in six different scenarios. The effectiveness of the models would be dependent on how closely the model predicts transport behavior in rock and shale and the similarity in behavior of different formations.

Laboratory studies are being performed to identifying potential impacts of inadequately treating hydraulic fracturing wastewater and discharging it to rivers. Experiments are being designed to test how well common wastewater treatment processes remove selected contaminants from hydraulic fracturing wastewater, including radium and other metals. Since wastewater treatment plants are not designed to remove more than biological waste and bacteria, any removal of fracking chemicals and contaminants would be incidental. I do not expect that wastewater treatment plants would be able to treat flowback water for the contaminants associated with geological formations and fracking chemicals.

The EPA has identified chemicals used in hydraulic fracturing fluids from 2005 to 2011 and chemicals found in flowback and produced water. The EPA is performing toxicity assessments based on chemical, physical, and toxicological properties for chemicals with known chemical structures. Existing toxicology models are being used to estimate properties in cases where information is not available. The important thing that EPA is doing is bringing together all the data and previous work to get as complete picture of what we know about how hydraulic fracturing may be impacting our water resources.

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. 

Is Our Drinking Water Safe?

The short answer is it depends on where your water comes from, and how it is treated. The drinking water supply can be broken down into three parts: the source water, the drinking water treatment system, and the distribution system which carries the treated water to homes and other buildings. The first steps towards a clean water supply and public health was to disinfect drinking water in the cities (and develop sewer systems). Treating drinking water with either Chloramine or chlorine lowered microbial densities of coliform bacteria, heterotrophic bacteria, Legionella bacteria preventing disease and death. However, these bacteria and the other substances on the primary drinking water list are not the whole story, nor are they the only substances in our water today. Our modern world is filled with chemicals, they exist in pharmaceuticals, household products, personal care products, plastics, pesticides, industrial chemicals, human and animal waste; they are in short, all around us. According to the Toxic Substances Control Act (TSCA) inventory of chemicals there are more than 84,000 chemical substances, as defined in TSCA today (or the last time they updated it). These chemicals include organics, inorganic, polymers, and UVCBs (chemical substances of Unknown or Variable composition, Complex reaction products, and Biological materials).

Public drinking water supplies are still typically treated with either Chloramine or chlorine both are disinfectants. (Disinfection by products are tested for in drinking water supplies.) Chloramine is a combination of chlorine and ammonia that is currently considered best technology for controlling the formation of certain regulated organic disinfection byproducts and has come to replace the use of chlorine in many locations. Since the revisions to the clean water act in the 1990’s chloramine has returned to common use as a distribution system disinfectant after being replaced in 1940’s with chlorine when there were ammonia shortages. Chloramine lowers microbial densities of coliform bacteria, heterotrophic bacteria, Legionella bacteria in the source water and distribution system while minimizing the formation of regulated disinfection by-products.

Under the authority of the Safe Drinking Water Act (SDWA), EPA sets standards for approximately 90 contaminants in drinking water including bacteria from human waste, industrial discharge streams (of great concern back in 1974 when the SDWA was first created) and water disinfection by-products and distribution system contaminants. For each of these contaminants, EPA sets a legal limit, called a maximum contaminant level. EPA requires that all public water supplies be tested for this list of contaminants on a regular basis (from daily, to quarterly, to every other year or longer depending on the contaminant and water system) and meet these minimum standards on average. In addition, EPA sets 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. Though 90 contaminants is a lot, it is just a small fraction of the chemicals in large scale commercial production in the United States which EPA estimates to be over 7,000 chemicals.

Several of the substance controlled under the SDWA are natural occurring contaminants, 6 are bacteria and 8 are by-products or additives of water treatment; however, the greatest problem is pollution caused by mankind. Anthropogenic pollutants contaminate surface and groundwater as a result of manufacturing, combustion and incinerations air emissions, landfills and spills, stormwater runoff carrying agricultural and surface pollutants and waste water treatment water carrying a wide range of chemical containing substances into surface water and groundwater. The SDWA is a product of its time, in 1974 industrial waste discharge and release was far more common, and the last significant review of the SDWA was 1991. Six of the chemicals regulated under the SDWA have been banned for more than 20 years, but the US Geological Survey (USGS) found traces of at least one banned pesticide in groundwater during the recent study of the quality of the nation’s ground water supply.

The USGS ground water testing found that 10 contaminants were detected at concentrations greater than human-health recommended levels in 1% of the groundwater. Of the ten contaminants, seven were from natural sources and three were man-made. The seven contaminants from natural sources included four geological trace elements (arsenic, manganese, strontium, and boron) and three radionuclides (radon, radium, and gross alpha-particle radioactivity). The three contaminants that exceeded MCLs that were from man-made sources were nitrate (a nutrient), dieldrin (an insecticide that has been banned by the US EPA), and perchloroethene (PCE). Naturally occurring elements, radionuclides and pesticide compounds were extensively found at extremely low concentrations (about 10% of any existing health standard). Trace levels of an herbicide (atrazine or simazine) or an herbicide degradate (deethylatrazine), and the solvents perchlorethene or trichloroethene were widely found in samples from shallow unconfined aquifers without a confining geological layer, though the deeper confined groundwater aquifers remained mostly free of man-made contamination.

In their study of surface water used for drinking water supplies the USGS found a diverse group of contaminants in the source water. The concentrations were low, but the contaminants were ubiquitous. This would indicate a variety of different sources and pathways for these contaminants to reach our drinking water supplies. The concentrations were low, (about 95% of the concentrations were less than one-part per billion); nonetheless, the most commonly detected contaminants in source water were generally detected in finished water at about the same frequency and concentration. Our drinking water treatment systems do not remove these contaminants. The USGS found that as the amount of urban and agri-lands increased within the water shed, the numbers of contaminants in the rivers also increased. Rivers receiving municipal and industrial discharge, as well as discharges from other point and non-point sources from stormwater runoff are impacted by man-made organic contaminants, most of which are unregulated. Only about 40 of the 260 substances the USGS tested for are regulated the rest are unregulated.

The safety of our drinking water system is predicated on the basic assumption of toxicology that “dose makes the poison.” This relationship between exposure and risk has been challenged in the study of endocrine disruptors. Now, there is growing concern for potential endocrine disruptors at extremely low levels. Endocrine disruptors are chemicals that can mimic, block, or otherwise alter animal hormone responses, sometimes affecting their reproduction, development, and behavior, this is actually, how some pest control treatments are designed to work on bugs. A diverse group of chemicals called endocrine disrupting chemicals (EDCs) come from a variety of sources. These chemical have vastly different molecular structures, and become of great concern when they are discovered to be human endocrine disruptors.

The US Fish and Wildlife Service (USFW) and US Geological Survey (USGS) studied the relationship between waste water treatment plants, agricultural chemicals, and the immune-suppressed and inter-sexed fish in the Potomac River (and other locations). Hormones were not detected in the samples, but analysis using yeast screening assays found estrogenic endocrine-disrupting chemicals throughout the sections of the rivers tested, yet their specific source has not yet been identified. The extremely low concentrations of chemicals that was almost undetectable caused significant biological and health impacts among the fish and amphibian populations. Though they cannot identify a single chemical or group of chemicals responsible, the USFW and USGS have embarked on further study to gain greater understanding of the implications of their findings to the earth’s ecosystem.

The structural diversity of potential endocrine disruptors is enormous and it is not known which of these substances might adversely affect living things in subtle ways. Testing for new chemicals is for gross and acute impact, subtle impact is very difficult to identify. The growing class of known endocrine disrupting chemicals can disturb a staggering range of hormonal processes. Like natural hormones, some EDCs bind directly with hormone receptors. The impostors can mimic or block hormone messages with the same, weaker, or stronger responses. Others are more subtle, they interfere with hormone maintenance to prevent or enhance hormones from being made, broken apart, or carried in the bloodstream.

Recycled or reclaimed water is former wastewater (sewage) that has been treated to remove solids, bacteria and certain impurities, and then is used in irrigation, discharged to surface water that is a source of drinking water or injected into the ground to recharge groundwater aquifers. In order to make our river, lake, stream and ocean water safe for fishing and recreation, the Clean Water Act of 1972 mandated elimination of the discharge of untreated waste from municipal and industrial sources. This was the first great success of environmental regulations. Modern waste water treatment plants, usually using sand filtration and chlorination in addition to primary and secondary treatment, were required to meet certain standards. These standards were never designed to render the waste water potable nor to remove the vast number of chemicals and drugs that find their way down our drains today. The design of the combined sewer systems in the largest cities results in regular discharge of raw sewage during storm events. In the United States the cryptosporidium parasite has caused outbreaks of diarrheal disease in the 1990’s and boil water alerts are frequent occurrences in the in the 21st century. We are having difficulties maintaining our most basic water quality let alone protect the population from emerging contaminants. The Environmental Working Group has called for the EPA to do a national assessment of drinking water quality and establish new safety standards, set priorities for pollution prevention projects, and inform the public of the full range of pollutants in their water. In the meantime, while the EPA spends it time addressing carbon dioxide in the atmosphere you need to carefully consider source water quality, and treatment when selecting where to live.

Raspberry Falls Bearing the Cost of Water Problems in Karst Terrain

The karst area of Loudoun County is contained within the limestone overlay district that was created in 2010 when Loudoun County Board of Supervisors approved the re-adoption and re-enactment of the Limestone Overlay District (LOD). This district is the area of the county generally north of Leesburg and east of the Catoctin Mountains which is underlain by limestone conglomerate bedrock and runs north along Route 15. The LOD is really an amendment to the zoning to try and address the ecological and environmental challenges associated with karst terrain. The LOD attempts to ensure that the groundwater supply is capable of supporting needs of the eventual inhabitants of new subdivisions and the land can support the septic needs of current and future residents without impacting the water supplies of existing residents and creating sinkholes that could endanger their properties. Karst terrain is fragile and ignoring the limits of natural systems can have serious consequences.

Raspberry Falls is a clustered development around a golf course in the LOD of Loudoun County. While clustered development usually involves fewer disturbances to natural landscape, and is encouraged in low impact development designs, golf courses are not a low impact design feature. The groundwater pumping to feed the homes and water the golf course may create or exacerbate problems in karst terrain, especially during droughts. The turf management herbicides can also be a problem. The Raspberry Falls development was originally approved for 206 homes and currently has, I believe, 134 homes that are served by a community water system consisting of two wells built out by the developer and operated by Loudoun Water. The system has been plagued by the bacterial problems that are a common problem with karst terrain. Fractures in the overlying limestone become enlarged over time and provide a direct route of surface water to groundwater. Sinkholes proved another direct path for surface contaminants to enter the groundwater as do sinking streams and rivers. The faster water moves into the ground the higher the likelihood that bacteria will remain alive and nitrate is not going to denitrify. When that happens the groundwater is deemed to be, Groundwater Under is the Direct Influence of Surface Water or GUDI. A water source is determined to be GUDI if more than 10% of total coliform numbers exceed 100 cfu/100 mL.

One of the water supply wells for Raspberry Falls was determined to be GUDI by the Department of Health and taken out of service and replaced this past year by a new well at a cost of almost a million dollars. Replacing the well solved the problem for the short term, but experience in the western third of Virginia has demonstrated that the GUDI condition could impact the other wells. Local septic systems did not appear to be the source of bacterial contamination, but E coli numbers were not broken out in the raw water data by Loudoun Water, only total coliform. However, wastewater in Raspberry Falls is collected and treated to a at the community wastewater treatment plant (WWTP). Most organic material and nutrients are removed through biological treatment before being disinfected and discharged to an unnamed tributary of Limestone Branch.

Though the GUDI well was replaced with a new well (and right now the water meets all the standards of the Safe Drinking Water Act), additional treatment beyond the current chlorine disinfection of the drinking water is being considered because of the relatively easy connection of surface water to groundwater, the unconfined nature of the groundwater aquifer and probably the immediate problems with turbidity that the new well experienced. Two options were considered and studied by Hazen and Sawyer (Loudoun Water’s consultant): the extension of municipal water from Leesburg into the Rural Policy Area that encompasses Raspberry Falls or the installation of membrane filtration for all Raspberry Falls water supply wells as an additional water treatment step. The extension of the municipal water pipeline would involve an amendment to the Loudoun County Revised General Plan to authorize extending the pipeline and the Town of Leesburg would need to accept ownership and operation of the Raspberry Falls Community Water System.

The costs associated with the installation of membrane filtration and operation were $4 million for purchase and installation and $67,000 additional in annual operation costs for Raspberry Falls only. Loudoun Water estimates that the cost per lot would be an additional $1,830/year for membrane filtration. The Town of Leesburg estimated the construction cost of the pipeline at $7.5-$8 million, with annual operating costs of $418,000 and an annual cost per lot of $4,260/year. The recent water rate increase does not take into consideration either of the options under consideration. The membrane filtration was the cheaper option, and would still carry significant costs that would ultimately be paid for by the water system customers. Loudoun Water appears to prefer the cheaper membrane filtration system, and though residents might suspect business concerns took precedence over water quality issues, it may be an excellent solution given what is known about the source water quality. Loudoun Water has requested that Loudoun County and the Town of Leesburg decide whether to pursue the pipeline extension no later than May 2012 otherwise they will proceed with installation of membrane filtration at Raspberry Falls.

There appears to be many residents who strongly support the pipeline/ Leesburg water solution despite the higher cost. Appropriately, many residents are only concerned about obtaining the best water supply possible, but the pipeline may not be that answer. Personally, after reviewing the US Geological Service (USGS) raw water studies and the USGS and US Fish and Wildlife (USFW) studies into skin lesion on bass in the southern branch of the Potomac River, I would hesitate to pay extra to drink water sourced from the Potomac River without advanced nanomembrane filtration. The USGS found fish suffering from a variety of lesions. Some fish had bacterial lesions, some fungal lesions, and some fish had parasite. The USGS concluded that there was no specific cause of the lesions and that the fish appeared to be immunosuppressed so that any pathogen in the water could attack the fish. A series of studies were performed over a period of years. During the investigation it was discovered that male fish had immature female egg cells in their testes and the females had lowered levels of an essential protein in the formation of eggs. The bass suffering from lesions were intersexed.

It had previously been demonstrated that estrogen and estrogen mimicking compounds can cause intersex. The occurrence of intersex among the lesioned fish prompted further studies. The study found the problem of endocrine disruption in fish to be widespread in the limited study area of a portion of the Chesapeake Water Shed and Potomac River, but increased in proximity to and downstream of the waste water treatment plants. Chemical sampling that took place along with the fish sampling found higher concentrations of waste water chemicals near the waste water plants. Pesticides, herbicides and their breakdown products currently used in agriculture were detected at all locations. Hormones were not detected in the samples, but analysis using yeast screening assays found estrogenic endocrine-disrupting chemicals at all locations their specific source is not yet known. None of these chemicals are currently regulated under the Safe Drinking Water Act, SDWA, and so would not be tested for or treated by the Leesburg town water treatment system except by happy coincidence.

Before the residents of Raspberry Falls choose a solution to their water problems they should consider carefully the quality of the source water and finished water. USGS groundwater source studies have also found the presence of the gasoline additive MTBE, the solvent 1,1-dichloroethane, and the herbicide breakdown products from alachlor and atrazine in a significant percentage of groundwater supply wells in unconfined aquifers. The herbicide degradates are not regulated by the USEPA in drinking water under the SDWA, so these contaminants are not tested for in drinking water and there are no known health screening levels. Though these herbicides are widely used in agriculture and turf management for golf courses and the herbicide degradates may be regulated by USEPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Though whatever solution Loudoun County Supervisors and the residents of Raspberry Falls choose will have additional costs associated with it, this is a rare opportunity to select your source water and potentially your treatment method after purchasing your home. Performing extensive source and finished water analysis before making a final decision might be very worthwhile in this instance.

National Groundwater Week

It is National Groundwater Awareness Week March 11-17, 2012, and apparently Awareness Week is in its second decade of existence. Who knew, and that’s the problem, most people are unaware of groundwater despite its importance and impact on our lives. Recently, the US Geological Survey, USGS, reported that in 2007 105 million people, about a third of the population receive their drinking water from one of the 140,000 public water systems across the United States that use groundwater as their source. In addition, 15% of the population obtains their water directly from groundwater using private drinking water wells. Groundwater is also used for irrigation. Groundwater is an important natural resource, especially in those parts of the country that don't have ample surface-water sources, such as the arid West. Groundwater is a renewable resource, but not unlimited. Groundwater recharges at various rates from precipitation and other sources of infiltration.

Unlike other natural resources or raw materials, groundwater is present throughout the world varying from place to place, depending on rainfall conditions and the distribution of aquifers (rock and sand layers in whose pore spaces the groundwater sits). Precipitation and soil type determines how much the shallower groundwater is recharged annually. However the volume of water that can be stored is controlled by the reservoir characteristics of the subsurface rocks. Generally, groundwater is renewed only during a part of each year through precipitation, but can be abstracted year-round providing a reliable and clean source of drinking water to much of the population provided there is adequate replenishment, and it is protected from pollution. We need to be aware of the source of our groundwater it’s natural recharge rate and protect our aquifers from over use and contamination.

Groundwater is usually cleaner than surface water and as source water for drinking water supplies it is often superior to surface water. Groundwater is typically protected against contamination from the surface by the soils and rock layers covering the aquifer. This water is the only available clean drinking water in many areas. However, rising population, changes in land use, agriculture and industrialization increasingly place groundwater in jeopardy of contamination. Once contaminated, groundwater is very difficult to clean and often after removal of contaminated plumes only long term abandonment of use to allow for natural attenuation is the only possible course of action. Precious groundwater resources increasingly need to be protected from contamination and well managed to allow for sustainable long-term use.

Though the water quality of the public water supply systems is regulated by the US EPA under the Safe Drinking Water Act (SDWA), drinking water supplies are only tested for slightly over 90 contaminants (many of them natural impurities) when there are over 80,000 chemicals known in the United States. In addition, the US EPA only regulates the finished water delivered to consumer through public water supply systems. The underlying groundwater quality often has not been tracked by the US EPA. In their study of the quality of groundwater sources in the United States, the USGS found trace levels of pesticide compounds (not regulated under the SCWA) or VOCs in 64% of the groundwater samples taken from public water supply wells. Three-quarters of the organic-contaminants contained an herbicide (atrazine or simazine) or an herbicide degradate (deethylatrazine), and about 40% contained the solvents perchlorethene or trichloroethene. Pesticides and VOCs were detected in a significantly greater proportion of samples from unconfined aquifers than in samples from confined aquifers. The groundwater with the greatest number of contaminants was consistently from shallower unconfined aquifers demonstrating the natural protection provided by a confining geological layer.

Groundwater typically contains geological trace elements such as arsenic, manganese, strontium, iron, and boron and radionuclides (radon, radium, and gross alpha-particle radioactivity). These contaminants originate from the rocks and sediments that contain the aquifers and are entirely natural, but there are health related maximum contaminant level standards for these elements within the SDWA. For groundwater supplies, the concentration of these geological contaminants does not change quickly over time and remains rather constant in any given region. What is changing is the appearance of modern pesticides and herbicides, substances atrazine or simazine and their breakdown products in groundwater. These chemicals slowly percolate into groundwater from land application of pesticides and herbicides used for greener lawns and gardens or for agriculture. They appear in shallower groundwater supplies. Another source of contamination of groundwater is our septic systems. It is estimated by various sources that 25-35% of all US homes use septic systems.

There are many different types of septic system designs. The most common type used for single family homes consists of a septic tank and leach field. A septic tank can be an anaerobic (without air) tank or an aerobic tank (with air). The anaerobic system is a single chamber tank that receives the toilet and drain waste from the house and allows the solids to settle down to the bottom of the tank where the anaerobic bacteria that live in the tank digest the organic materials while the effluent (water around all that stuff) flows out to the leach field to be purified by passing through soil until it reaches the groundwater. The final finishing for septic waste is the leach field or other soil absorption system, where it percolates into the soil, which provides final treatment by removing harmful bacteria, viruses, and nutrients. This is a natural process requiring suitable soil for successful waste water treatment, but even with the most suitable soil septic systems cannot remove chemicals from the water. Household cleaners, fertilizers, pesticides, pharmaceuticals and personal care products will just pass through the system and begin to appear in the recharge to the groundwater.

As our homes are filled with ever more powerful and chemical laden cleaners, antibacterial soaps, pesticides, herbicides, paints, petroleum products, insecticides and drugs-all the wonders of modern life, these things find their way into our waters. Through stormwater runoff and waste water treatment plants these things easily find their way to our surface waters. Waste water treatment plants are no more equipped to treat waste water for these chemicals than a septic system is and quite frankly none of these public supplies of water are routinely tested for these substances. Waste water treatment plants do not have chemical removal processes. Through our septic systems, and gardens and yards these contaminants are appearing in our groundwater. Although each septic system and yard can make an insignificant contribution to ground water contamination, the sheer number of such systems and their wide spread use of pesticides and herbicides in every area make them serious contamination sources. What goes down the drain or is sprayed and spread in the garden goes into the groundwater. To make a difference we all need to protect our groundwater.

The following actions to protect groundwater from contamination and are based on recommendations from the National Groundwater Association:
1. Properly store hazardous household substances like paints, paint thinners, petroleum products, fertilizers, herbicides, insecticides, and cleaning products in secure containers
2. Mix hazardous household substances over concrete or asphalt where they can be cleaned up or absorbed onto disposable media like paper towels and then properly disposed of with hazardous material waste.
3. Dispose of hazardous household wastes at an appropriate waste disposal facility or drop-off. Most landfills and city trash programs have these drop-offs.
4. Do not put hazardous household wastes down the drain or in the toilet ever,
5. Do not put any wastes down a dry or abandoned well or use sinkholes as waste disposal holes.
6. Service your septic system regularly at a minimum service it according to local health department recommendations
7. Check your private drinking water well annually to make sure the sanitary seals are intact.
8. Decommission abandoned wells on your property using a qualified water well contractor
9. Fix or replace any leaking aboveground or underground tanks storing hazardous substances. All underground storage tanks should have secondary containment to prevent contamination of the subsurface. All tanks will eventually fail.

Protecting Drinking Water in Karst Terrain

Most of us are familiar with the caves and the more striking karst features that occur in karst terrain though visits to the National Park System and caverns. My own introduction to karst features was Howes’ Caverns in New York where the stalactites, stalagmites and flowstone created from the calcite dissolved from overlying rock was a wondrous site for a child. My husband, a native son of Virginia, went to Luray Caverns as a child. In Virginia karst terrain covers much of the Valley and Ridge Province in the western third of the state. Smaller karst areas occur in the Cumberland Plateau, Piedmont and Coastal Plain Provinces, too. Cave systems are just some of the features that occur in karst terrain. Karst terrain may including sinkholes, fractured bedrock, sinking streams, and sinkhole ponds that are all direct routes of groundwater recharge that provides little if any containment or removal of contaminants of surface waters that recharge karst aquifers. Ground water flows rapidly through karst aquifers, through the enlarged solution channels, discharging from springs and supplying base flow to surface streams and rivers.

Karst terrain occurs in areas where the underlying rocks are carbonate rock such as limestone (CaCO3), dolomite (CaMg(CO3)2) and gypsum (CaSO4.2H2O). These rocks are soluble in dilute acids and typically have only a thin soil overlay with areas of rock outcroppings. Rain water becomes slightly acidic when passing through decaying organic debris in the surface soils. The decaying organic material is a ready source of carbon dioxide, CO2. The CO2 and H2O chemically react to form a weak acid called carbonic acid. The slightly acidic water percolates down through the soil into fractures in the carbonate bedrock. These types of rocks are the very type of rocks used in the filters to neutralize acidic or corrosive well water because they easily react with the slightly acidic rain water. The carbonic acid in the moving ground water slowly dissolves the bedrock forming passageways and caves. This geological process results in unusual surface and subsurface features ranging from sinkholes, disappearing streams and springs to complex cave systems and caverns that are the characteristic Karst features.

These Karst features are very important to understand because approximately 20% of the land in the United States is classified as karst topography, but these areas produce 40% of the groundwater used for drinking water in the United States. World wide approximately 10% of the earth's surface is classified as karst; with an estimate 25% of the world's population living in karst areas. The hollow nature of karst terrain results in a very high pollution potential. The thin soils over fractured limestone allow precipitation to enter the subsurface with minimal natural filtration. Streams and surface runoff enter sinkholes, fissures and caves, carrying surface contaminants and without the natural filtration provided by soil and sediment cover the contaminants quickly flow to depth. Groundwater can travel quite rapidly through these underground networks. In tests by the U.S. Geological Survey and the U.S Environmental Protection Agency, groundwater was documented to travel thousands of feet, even miles, per day transmitting tracer dyes and potentially contaminants to wells and springs throughout the vicinity. In karst terrain groundwater can flow like an underground river.

Karst aquifers are among the most highly vulnerable to contamination, particularly where the overlying soil is thin. This vulnerability results from: sinkholes, widened flow paths, and rapid velocities of ground water and contaminants. Contaminants can be transmitted quickly from entry in a sinkhole to wells and springs in the vicinity. A sinkhole is generally a funnel-shaped or steep-sided depression that is caused by the underlying carbonate rocks dissolving away and the subsidence of the land surface into a subterranean passage, cavity, or cave. Sinkholes proved a direct path for surface contaminants to enter the groundwater. Sinkhole creation, sinkhole flooding, and groundwater contamination are the major hazards associated with karst terrain, and unlike other natural hazards they are chronic in nature. Rapid infiltration of surface water allows bacteria to reach groundwater depth while still alive. Also, rapid infiltration does not consume a lot of the oxygen in the water and nitrate does not denitrify making karst aquifer highly susceptible to bacterial and nitrate contamination (major contaminants in human and animal waste).

Sinkholes are easily formed in karst terrain. Alterations to surface runoff during development can cause sinkholes. Groundwater pumping can quickly lower the water level and result in a subsidence or sinkhole formation. Failing septic systems are a significant source of groundwater contamination in karst terrain. Also, there are many cases of septic tanks simply sinking into the underlying cave system in karst areas. Rather than devastating natural disasters, karst terrain unwisely developed has resulted in long-term economic burdens on individual property owners and communities for sewage and water treatment in sparsely developed areas. The residents of karst areas need to be aware of how day-to-day activities affect the groundwater and fragile ecosystems in their karst regions. In addition, surface water can directly influence groundwater carrying with it all the surface bacteria and contaminants that source groundwater is not typically treated for.