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.

Corrosive Water- VAMWON Notes From the Field

VAMWON Notes from the Field are the water/ well problems I’ve encountered as a volunteer with the Virginia Master Well Owner Network (VAMWON), an organization of trained volunteers and extension agents dedicated to promoting the proper construction, maintenance, and management of private water systems (wells, springs, and cisterns) in Virginia. The Cooperative Extension Services in Virginia manages the program and has publications and fact sheets that can help homeowners make educated decisions about their drinking water. The VAMWON volunteer or Agent can help you identify problems with the water system and provide information on suggested treatments options and other solutions. You can find your VAMWON volunteer neighbor through this link by entering your county in the search box.

I was contacted by a homeowner who had his water tested by a water company and wanted to know if his water was safe to drink without treatment. He reported the results to me as follows:
Hardness - 3 gpg
pH - 6
CO2 - 40 ppm

The tests performed did not test for bacteria, chemical contaminants, only for pH and hardness. From that information there was no way to know if the well water was in fact safe to drink. The test was free and offered by water treatment companies that were trying to sell him water treatment systems so it only performed an inexpensive test for pH, derived CO2 and hardness- characteristics they could sell water treatment systems to address.

Water hardness is usually measured by adding up the concentrations of calcium, magnesium and converting this value to an equivalent concentration of calcium carbonate (CaCO3) in milligrams per liter (mg/L) of water. However, it can also be measured in grains per gallon. Water with a hardness of 3 gpg is equivalent to 51 mg/L . This water was soft and required no treatment.

Many characteristics of water actually determine its corrosivity including pH, calcium concentration, hardness, dissolved solids content and temperature. Water that is soft and acidic tends to be more corrosive, but water corrosivity is usually measured by saturation indices. Water with a pH lower than 6.5 is commonly called corrosive or aggressive water by water treatment sales people, which simply means it is slightly acidic. While consuming corrosive or aggressive water is not in itself dangerous, consuming some of the contaminants that may be dissolved from metal plumbing by corrosive water may pose health risks, particularly metals like copper and lead. That concern is mitigated if the household plumbing is PVC rather than metal piping. Corrosive water can also shorten the life of hot water heaters, washing machines and dishwashers. The pH scale is logarithmic. This means that water that has a pH of 6.0 is 10 times more acidic than water with a pH of 7.0, nonetheless, the water with a pH of 6 is about as acidic as a latte from Starbucks. It is not necessary to treat slightly acidic water if household piping is PVC, but treatment can be done simply with an acid neutralizing filter.

It is possible to measure CO2 directly in water using a TOC carbon analyzer. The injected sample is acidified to purge all of the CO2, which is then measured on an IRGA - infrared gas analyzer-detector. It is very unlikely that the fee test offered by a water treatment company used that level of analysis. H2CO3 and dissolved CO2 are in equilibrium with each other. Typically CO2 is a derived value using the pH measured at the tap. There is no drinking water standard for dissolved CO2, typically dissolved oxygen and CO2 content are of concern for ecosystem balance in surface waters. Ground water typically has CO2 concentrations under 50 ppm and I believe the derived measurement was given because CO2 has lots of “buzz” around it.

The calcite and calcite-blend filters used to neutralize corrosive water in homes work by adding calcium to the water, and will increase the calcium carbonate, hardness, of the water, making the water 'harder'. However, most acidic well water is soft to begin with, and after passing through the neutralizing filter it will be harder, but usually not hard enough to warrant a water softener. Generally, if the water is less than 170 mg/L or 10 grains per gallon, the water does not need softening. His water was 3 grains/gallon to begin with, after the neutralizer it would be expected to be 5 to 7 grains per gallon, as neutralizers typically add 3 - 4 grains per gallon on average. His water should still be well below what is considered “hard” and should not present any significant problems. Hard water can cause spotting and lime scale buildup in appliances shortening the life of hot water heaters, dishwashers and washing machines.

Acid-neutralizing filters consist of a corrosion-resistant tank filled with calcite (calcium carbonate in the form of limestone or marble chips) or a mixture of calcite and magnesium oxide (also called corosex). Neutralizer filters cost under $1,000 for homes with 3-5 bathrooms (installation is extra). Once you install a water treatment system, it must be maintained properly. Frequent maintenance is required for neutralizing filters. The tank must be routinely refilled with neutralizing material as it is dissolved. The rate of refilling can range from weeks to months depending on the raw water corrosivity, water use, and the type of neutralizing material. Backwashing is recommended to remove trapped particles that can promote bacterial growth and oxidized metals unless a sediment filter is installed ahead of the unit then of course the sediment filter will require maintenance. Always consider carefully if you should be treating your water before you start buying and installing water treatment systems.

A drinking water well that is contaminated could significantly impact your health and the value of your property. There is no requirement to test private drinking water wells for all the primary and secondary contaminants of concern to the US EPA under the Safe Drinking Water Act. The local health departments have local rules and regulations for the installation of wells and initial testing of the water for bacteria, but as the well owner you will need to take the initiative and test your water to make sure it is safe to drink. None of the testing done so far on this well would have tested if the water was safe to drink. Though there are many potential contaminants to groundwater that can impact your health, the Virginia extension recommends at a minimum testing for: total coliform, E. Coli, sulfate, nitrate, fluoride, copper, lead, arsenic, hardness, total dissolved solids, pH, manganese, iron, sodium.

The Virginia Extension Office runs several subsidized water clinics each year. This year, 2012, we will be having a clinic in Prince William County in the early winter. Albemarle County will be having a clinic in April 2012, Loudoun and Frederick counties will have water clinics in May 2012, Page, Shenandoah and Warren counties will have water clinics in June 2012. Water analysis for the clinics is being subsidized by the Extension program and will cost only $55 trained extension agents and volunteers will be available to interpret your results.

500 Feet From Your Front Door-Pennsylvania Passes HB 1950

On February 8, 2012, the Pennsylvania General Assembly passed House Bill 1950 amending the Commonwealth’s Oil and Gas Act (the “Act”). It was signed into law on February 13th 2012 by the Governor. Under HB 1950, an impact fee will be levied on each fracked gas well and is anticipated to yield between $190,000 and $355,000 per well in the first 15 years. The funding will be split between local municipalities and the state. In addition, this legislation restricts local municipalities’ ability to use zoning regulations to restrict drilling and hydraulic fracking in residential neighborhoods, taking away residents ability to make decisions about drilling that best fits the needs of their communities. HB 1950 increases setbacks, providing that the shale gas wells are 500 feet from occupied structures and water wells, and 1,000 feet from public drinking water wells. In addition to the setbacks, the new law prohibits wastewater pits within the 100 year floodplain, requires new fracturing fluid chemical disclosure, requiring all operators to complete a chemical disclosure form and post the form on the chemical disclosure registry, FracFocus.com. Other items required under the law are additional well permitting procedures, plans, and approvals, increased bonding requirements and stricter enforcement and higher fines. Finally, the new law requires drillers to notify all surface rights owners within 3,000 feet of a well head.

In Pennsylvania, ownership of surface rights and ownership of minerals rights are often separated. In addition, mineral rights on the same tract may be separated from each other - oil, gas, coal, hard rock minerals, etc. may all be owned by separate companies. The mineral rights were usually separated before land was partitioned so that an individual or corporation may own the rights to an entire neighborhood. Pennsylvania does not maintain ownership records of mineral properties in a central location nor do they have property tax records for the mineral rights because they do not pay property taxes on those rights. Rather; county governments maintain the old transfer records that contain this, you could be surprised to find that a corporation already has the right to drill within 500 feet of your house, but under the new law they will have to notify you of their intent to drill.

All surface and mineral owners have property rights under the law. Pennsylvania recognizes both the mineral owner's right to recover the mineral, and the landowner's right to protection from unreasonable encroachment or damage. Some towns had attempted to control hydraulic fracturing and shale gas processing through zoning. Now, HB 1950 effectively removes oil and gas drilling and related gas processing activities from nearly all local land use regulation, including regulation under the Municipalities Planning Code. According to Richard A. Ward, Township Manager Robinson Township, PA, this bill effectively turns the entire state of Pennsylvania into one large industrial zone. No zoning could exclude fracking wells and shale gas processing and no neighborhood is safe.

This bill amends Title 58 (Oil and Gas) of the Pennsylvania Consolidated Statutes, consolidating the Oil and Gas Act modifying the definitions, well permitting process, well location restrictions including increasing horizontal setbacks from water supply wells to 1,000 feet, reporting requirements, bonding, enforcement orders, penalties, civil penalties and, restricting local ordinances relating to oil and gas operations; and taxing the gas. However, the most significant element would in effect take away from the towns the ability to use zoning to exclude shale gas production in residential neighborhoods.

While it would undoubtedly be beneficial for the industry and regulators to have a single set of statewide regulations for siting and drilling hydraulic fracturing wells, watershed characteristics and geology vary across the state. Furthermore, the health and welfare of communities are best protected by local zoning. There has not been enough data gathered and studied to know horizontal distance to a drinking water well and aquifer will guarantee safety for the water supply throughout the various localities in the state and the 1,000 feet required under HB 1950 has no basis in scientific fact. Though it took several years, the legislation still seems in a rush, to generate taxes and jobs. The gas will still be there if we take the time to understand fracking adequately to be able to release the gas from the shale formations without significant damage to our water resources and communities.

More than One Way to Frack a Well

Our ability to recover natural gas buried in deep geological deposits beneath the earth has increased dramatically due to advances in horizontal drilling which allows a vertically drilled well to turn and run thousands of feet laterally through the earth combined with advances in methods to "hydraulically fracture" or "hydraulically stimulate" the formation to generate cracks or "fractures" through which gases and liquids can flow more rapidly to the well. Hydraulic fracking as it is typically called is the pumping of millions of gallons of chemicals and water into shale at high pressure to increase the recovery of oil and natural gas from shale.

In hydraulic fracking on average 2-5 million gallons of chemicals and water is pumped into the shale formation at 9,000 pounds per square inch and literally cracks the shale or breaks open existing cracks and allows the trapped natural gas to flow. The use of water laced with chemicals to enhance oil and gas production has been very successful in the United States with many improvements in the technique since its inception in the 1950's. Water-based fracturing liquids (once called slickwater) are the most commonly used in the lower shale formations like the Marcellus. Generally, chemical additives are mixed with the water to improve its ability to transport the proppant, the sand or other substance used to prop open the fractures to allow the gas to flow. This is achieved through the addition of gels to increase the viscosity and also to reduce fluid loss from the fracture by temporarily blocking the natural permeability of the rock. Once the pumping is completed, the gel breaks down and the spent liquids can flow back to the surface after which the gas can flow up to the well bore. This works well in the higher pressure formations where the back pressure from the formation can push the liquids out of the formation rather than absorb the liquids into the formation.

While geologists and engineers believe that there is little risk that the fracking “water,” a mix of chemicals and water, will somehow infiltrate groundwater reserves though a fissure created by the fracking. It is believed that the intervening layers of rock would prevent a fissure from extending thousands of feet to the water table, but there are other risks in how we build wells and fracture the shale. There have been documented cases of seepage into drinking water wells through improperly sealed or abandoned drilling wells. There are also places where groundwater is only several hundred feet above the gas reserves as in Wyoming and groundwater is more easily directly impacted by fracking. In the past decade the advances in drilling and fracking technology have been adapted to exploit gas in the Barnett shale in the Fort Worth Basin in Texas and applied to a series of major shale gas deposits that could not have been viable without the advances in drilling and fracking techniques.

A mild winter combined with the newly available gas supplies has resulted in a crash in gas prices. At the current rate of natural gas consumption North America is reported to have a 100-year supply of proven, producible reserves and even with expanded use of natural gas to replace coal in fueling power plants, there is more than a generation of currently accessible reserves. The falling price of natural gas and disappointing life span of hydro fracked wells has renewed interest in other methods of fracturing a formation to increase the gas recovery over the life of the well and reduce the overall costs of fracking including the costs associated with waste water treatment to improve the economics of the project. Other methods of fracturing a formation have been used in formations where the gas reservoir is at a lower pressure and does not have sufficient energy to push the liquids back up the well. Without adequate pressure in the formation the liquids and chemicals used in the hydraulic stimulation process remain in the reservoir and impede the flow of oil and gas and shorten the lifetime of the well.

From the 1970’s until about 10 years ago it was standard to stimulate wells with nitrogen gas or nitrogen foam. Nitrogen gas and foam have a long history as the fracturing fluids of choice in the Antrim, New Albany, and Ohio (Lower Huron) shale where experience had shown a dry fracturing was superior. However, it was the Marcellus shale formations that tipped the balance to hydraulic fracturing. Water is non-compressible, drives net pressure better in shale stimulations than nitrogen foam fluids. Using water improved the chances of opening other planes of weakness or natural fractures with high pump rates and fluid volumes. It was believed that the Marcellus shale gas recovery was not significantly impacted by clays absorbing water and reducing overall gas production in a hydraulic frack; however, this belief may not prove to be true over the life of the wells.

Now, other methods of fracturing shale formations are being examined in response to the public outcry against the potential ground water contamination from hydraulic fracturing, excessive water use and earthquakes associated with some fracking water disposal wells combined with some hydraulic fracture wells experiencing a lower production yield than anticipated and the depressed price of natural gas. In the late 1990’s a series of test wells were drilled by industry and studied by the Department of Energy, DOE. These wells used liquid phase carbon dioxide, CO2, for fracturing and had significantly increased gas well yield over nitrogen fracked wells. In these wells, CO2 was pumped as a liquid then vaporized to a gas and flowed out from the reservoir leaving no liquid or chemical damage to the formation. This process can transport proppant in only limited volumes and requires a specialized blender to mix the liquid CO2 with proppant. These limitations were a problem for the lower shale formations where more proppant was needed.

Sometimes in a hydraulic frack the gels do not completely break down and even when they do, there is always some residue that remains in the well and can block and damage the gas reservoir. Hydraulic fracking gels create some damage, but the fractures were of sufficient length to offset the damage in the Texas wells which popularized the method. Some geological formations; however, do not respond as effectively to hydraulic stimulations. The fracturing liquids can become trapped in the formation because the reservoir is at a lower pressure and does not have sufficient energy to push the liquids back to the well bore. The gas well yields are diminished because the liquids and chemicals used in the fracking remain in the reservoir and impede the flow of oil and gas. These problems were slow to be addressed because of the high price for natural gas last decade, termination of the Gas Research Institute and a sharp decline in DOE gas research and technology program just as shale gas production was taking off.

Now with the low price for natural gas and contracts that require drilling, energy companies are looking for better methods of stimulating gas reserves. Chesapeake Energy Corp. has fractured a natural gas well in Ohio's Utica shale using a reported 471,534 gallons of water mixed with carbon dioxide, sand and chemical additives to create a foam that was pumped down the well under pressure to crack the underground rock. In nearby wells hydro fracked by Chesapeake the average water usage was 5.8 million gallons. Well production results from this CO2 foam and water fracked well will have to be evaluated over a period of at least 24 months and typically 36 months to know if this technique was successful, but it holds promise as a less resource damaging or wasting method to access shale gas.

The State of the Nation’s Groundwater

The US Geological Survey, USGS, and the US Environmental Protection Agency, US EPA, report that 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 from groundwater using private drinking water wells. The water quality of the public water supply systems is regulated by the US EPA under the Safe Drinking Water Act (SDWA), but the US EPA only regulates the finished water delivered to consumer and public water is often mixed with supplemental sources and treated so the quality of the underlying groundwater has not been tracked by the US EPA. The USGS monitors the quality and occurrence of contaminants in untreated groundwater. For the past decade and a half, the USGS has been studying groundwater quality in the United States.

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, which defined 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 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. Some substances have non-regulatory human health screening levels and then there are substances where no screening level has been determined and that is of growing concern. 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.

Scientists from the U.S. Geological Survey (USGS) tested water-quality conditions in untreated groundwater from 932 public wells, and also tested finished (treated) water from about 10% of the wells. Though the SDWA requires or recommends testing for 91 contaminants this program tested for over 300 contaminants, both naturally occurring and man-made in order to evaluate how widespread contaminants are in groundwater from public wells and their potential significance to human health and whether contaminants that occur in untreated groundwater also occur in finished water after treatment. This study is a great proxy for the state of the nation’s groundwater. I am one of the 45 million Americans who obtain their drinking water directly from groundwater using a private well and care deeply about the quality of the nation’s groundwater.

Though less than 1% of the groundwater public supply wells in the United States were tested, the samples from the systems tested represent source water used by about 26 million people. The USGS was able to test the groundwater that serves such a significant portion of the population by making sure that half of the groundwater wells sampled by the USGS were from very large systems in urban areas that are densely populated. Detection frequencies and the percentages of samples with contaminant concentrations greater than human health screening levels or MCL’s found in this study were similar to those observed in previous USGS studies. This happened because about 30% of the wells sampled in this study were also included in previous USGS studies and groundwater quality changes slowly in deep wells.

The USGS testing found that 10 contaminants were detected at concentrations greater than human-health recommended levels in at least 1% of the groundwater and accounted for most concentrations (74%) greater than MCLs or other human health screening level. 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). Radon has been considered several times for regulation in water in the past, but never seems to make the cut. There are; however, two levels of radioactivity that have been proposed as an MCL over the years-4,000 picocuries and 300 picocuries. Radon was found at the higher proposed Alternative MCL of 4,000 picocuries per liter (pCi/L) in less than 1% of samples, but was found above the proposed MCL of 300 pCi/L in 55% of the samples. Each of the remaining six elements and radionuclides was detected at concentrations greater than human-health benchmarks in 3%-19% of samples taken. These contaminants originate from the rocks and sediments that contain the aquifers.

The three contaminants that exceeded MCLs in at least 1% of samples from primarily man-made sources were nitrate (a nutrient), dieldrin (an insecticide that has been banned by the US EPA, but was previously used for termite control and other applications), and perchloroethene (or PCE, a solvent and degreasing agent used for drycleaning). Each of these contaminants was detected at concentrations greater than MCLs or HBSLs in 1% - 3% of the groundwater tested. Nitrate occurs naturally, but most nitrate concentrations greater than 1 milligram per liter (which is one-tenth of the nitrate MCL) originates from man-made sources such as fertilizers, livestock, and human wastewater from septic systems or wastewater treatment plants. Pesticides are released into the environment primarily through their application to agricultural lands, such as croplands, and to non-agricultural lands, such as lawns, golf courses, commercial landscaping and public areas.

There were several chemicals and compounds found at low levels determined to be at least 10% of the MCL or other human health screening levels. Naturally occurring elements, radionuclides and pesticide compounds were extensively found at these low concentrations. Trace levels of pesticide compounds or VOCs were detected in 64% of the groundwater samples from public 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 were consistently from shallower unconfined aquifers demonstrating the natural protection provided by a confining geological layer.

MCLs, HBSLs or other health screening levels were not available for 144 (43%) of the contaminants analyzed for in this study. Most of the contaminants without available health benchmarks were man made organic contaminants. Nine of these unregulated contaminants were detected in 6%-35% of groundwater samples. These contaminants were the gasoline additive MTBE, the solvent 1,1-dichloroethane, and the herbicide breakdown products alachlor ethane sulfonic acid, alachlor oxanilic acid, metolachlor ethane sulfonic acid, metolachlor oxanilic acid, deethylatrazine and deisopropylatrazine are which are break down products of atrazine. The ubiquity of these contaminants is worrisome. Most herbicide degradates found are not currently regulated by the USEPA in drinking water under the SDWA, but may be regulated by USEPA under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). It may be time for the USEPA to develop the toxicology data to evaluate the herbicide degradates for possible human health impacts.

Natural contaminants, the geological trace elements and radionuclides were found at concentrations exceeding human health screening levels or MCLs and at low levels in groundwater samples taken from unconfined and confined aquifers. This was expected since the source of these contaminants is the geological formations of the aquifer. However, most man-made contaminants were found 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 degradeates from the newer herbicides alachor and atrazine have penetrated a significant percentage of the nation’s groundwater and needs to be studied further and the widespread use for ornamental use should be reconsidered.

The Virginia General Assembly and Alternative Septic Regulations

The Virginia General Assembly convened on Wednesday, January 11th 2012. The session in this even numbered year is 60 days and will end on March 11th. Buried in Committee and hopefully soon to wither and die is a little bill HB 1071 Onsite sewage systems that would exempt the owners of an alternative onsite sewage system, AOSS, installed prior to January 1, 2010 and serving a church or an owner occupied single-family home from the requirements for AOSS under State Board of Health regulations until July 1, 2014. In essence this bill would exempt the older AOSS systems from being properly maintained. The Emergency Alternative Onsite Sewage System (AOSS) Regulations went into effect April 7, 2010 and were replaced by the final AOSS regulations on December 7th 2011. In the past two years homeowners received letters informing them of the requirements under the emergency regulations, and the requirements under the final regulations are almost the same as outlined by the Board of Health Letters sent to homeowners. At this point only irresponsible or ignorant homeowners are not properly maintaining their AOSS, and that is exactly who the regulations were written for.

Many Virginia home owners have both a private drinking water well and a septic system. To ensure a clean and healthy water supply both septic and well systems need to function properly. The most likely source of contamination to a drinking water well is a nearby septic system failure, and typically, the nearest septic system is your own, but can often by your neighbors. In 2003 EPA reported that 168,000 viral and 34,000 bacterial illnesses occur each year from drinking water contaminated by waterborne pathogens from fecal contamination. Proper maintenance of septic systems (both traditional and alternative) is essential for protection of public health and local water resources. If your home has a septic system of any type you are responsible for maintaining it. There are many different types of septic system designs, the AOSS systems were installed in soil that was ill suited to septic disposal. Ignored, these AOSS systems pose a threat to our drinking water and public health because the soils do not “perc.”

The “percolation rate” is the rate at which water moves through soil. The acceptable rates are between one minute and one hour per inch of soil. Take either more or less time for the water to pass through your soil and the natural soil is unsuitable for treatment of the waste water. If the water moves too slowly through the soil the leach field will flood with contaminated, foul smelling water or the water will back up into the house. If the water moves too quickly thought the soil the water will not be adequately treated and contaminate nearby ground or surface water. Alternative on-site sewage systems, AOSS, are the name given to waste treatment systems designed to adequately treat human waste without the help of adequate soil filtration.

One example of an AOSS is an aerobic system consists of a multi chamber tank or several tanks. After separation of solids in the first tank waste is forced through a filter into a second chamber or tank where air is pumped in to enhance aerobic bacteria which decomposes the organic material. The waste then flows into a third chamber or settling chamber which collects the bacteria and passes the liquid on to the leach field or drip field. Aerobic systems can remove more than 90% of the organic material and suspended solids within the tanks themselves, but require much more maintenance. Other type of AOSS include traditional septic tanks followed by treatment with tanks filled with peat, or sand mounds, or other soil absorption system that provide the secondary treatment. The problem is that alternative septic systems will not continue to function as designed without regular maintenance as my own experience and that of my neighbors has shown.

My libertarian streak would love to believe that homeowners would care for their septic systems appropriately to avoid the system backing up in the future, contamination of the groundwater (which may be the source of the local drinking water), and future septic system repair bills of tens of thousands of dollars to remediate and replace a system. Unfortunately, many homeowners are unaware of how septic systems work and what is necessary to maintain them. In addition, people do not seem to be able take appropriate responsibility for their systems and anticipate consequences of neglect.

One method to deal with this problem is to eliminate all but the most basic systems in the most geologically favorable locations (reduce percolation rate tolerances and design the systems as conservatively as possible). The Virginia General Assembly eliminated that option when they passed the enabling legislation for the Emergency Regulations in 2009 session. The other method is to regulate, control and track. Establish system performance and monitoring and maintenance requirements, establish a tracking system and operating permits for compliance monitoring. As a society we collect taxes, we license, register, and inspect cars; now we license, register and inspect/maintain AOSS. Loudoun County began requiring homeowners to maintain their AOSS (as required under their operating permits) in 2009. Their regulations were replaced by the state Emergency Regulations in 2010 and the final AOSS regulations in 2011.

The final AOSS regulations list the homeowner responsibilities as section 140 of the regulations.
12VAC5-613-140.
Owner responsibilities.
It is the owner's responsibility to do the following:
1. Have the AOSS operated and maintained by an operator;
2. Have an operator visit the AOSS at the frequency required by the permit (one or twice a year for single family systems);
3. Have an operator collect any samples required by this chapter (not required for “off the shelf” single family systems);
4. Keep a copy of the log of maintenance in electronic or hard copy form, make the log available to the department upon request, and make a reasonable effort to transfer the log to any future owner;
5. Follow the manufacturer’s O&M manual and keep a copy of the O&M manual in electronic or hard copy form for the AOSS, and make a reasonable effort to transfer the manual to any future owner; and
6. Comply with the onsite sewage system requirements contained in local ordinances adopted pursuant to the Chesapeake Bay Preservation Act (§ 10.1-2100 et seq. of the Code of Virginia) and the Chesapeake Bay Preservation Area Designation and Management Regulations (9VAC10-20) when an AOSS is located within a Chesapeake Bay Preservation Area (pump your tank at a minimum every five years).

These are the simple steps to maintain an AOSS and protect the source groundwater of the state. It is wrong to try to exempt the oldest and currently not maintained systems from the regulations for another two years. All citizen of the Commonwealth should insist that the General Assembly protect their drinking water.

Bad Water – Test it to Know

Bad water is a term that has popped up several times in community meetings. It is vague, and could mean almost anything. Though neighbors have declared at community meetings that old-timers “all say the water is bad”, they refuse to spend any money to test their drinking water wells, opting, instead, to buy bottled water to drink. The water they are calling “bad” is from the northwestern portion of the Culpeper groundwater basin that provides water to all our wells, and happens in fact to be quite good source water. When I purchased my home, one of my contingencies was water quality. I had the right to exit the purchase if the water quality was unacceptable to me. Though the seller was willing to accept my vague contingency all we could negotiate was a 12 day contingency period and in reality I had less time than that. The power needed to be turned on to operate the water pump, the pressure tank drained and the water run to clear out the well and lines which had been unused for six months.

There are reasonably priced informational oriented analysis package available to the consumer; however, the turn-around time for these products is about 4 weeks and the analytical limits were higher than I wanted for this first analysis. I was interested in obtaining a water supply as pristine as possible, and I would refuse any traces of any industrial compounds. I was specifically looking for solvents, hydrocarbon fuels, heavy metals and pesticide traces that might have resulted from previous land use or difficult taste quality issues. I determined my best option to verify water quality within the transaction time frame appeared to be to use an US EPA certified laboratory to perform a rush compliance analysis of the water sample for every primary and secondary contaminants listed under the Safe Drinking Water Act while simultaneously researching the history of the land.

The good news is the results confirmed that the on-site drinking water well provided water that met the Safe Drinking Water Standards and was free of even trace industrial contaminants only having traces (parts per million) of naturally occurring minerals such as iron, barium, cooper and moderately hard water (the presence of calcium carbonate), but even these secondary criteria were below recommended levels. I concluded the groundwater supplying the house was uncontaminated from its previous use as a dairy/cattle operation and the water quality good. To obtain that analysis within the time frame of the contingency period I spent $1,635.00, not an amount of money I could spend again, but the house was the most expensive purchase of my life and I did not want to purchase a house with that ambiguous “bad” water. The water also tasted good to me. What I missed during the rush analysis and investigation of the site was the risks of the local geology. Coming from California I had not been familiar with the local geological variations.

Groundwater flows under ambient pressure from Bull Run Mountain towards Bull Run, the river. Thus, groundwater flows west to east. The soils in our neighborhood and the surrounding area are described by the USGS as Balls Bluff Siltstone with a gravel, sand and clay type bedding plane. (That is the technical name for the flat plane, edged orange red rocks that are everywhere you put a shovel.) In the siltstone bedding plane, the fractures within the rocks run predominately north south. Thus while ground water flows generally speaking west to east, water or a contaminant that catches a fracture will carry the contaminant to drinking water depth in a north south pattern. Contaminants can enter the groundwater at these fractures and zigzag through the neighborhood. Though the neighborhood is bound by rivers to the east and south which serve as hydraulic breaks within the neighborhood we are an enclosed fracture system with a potential of contamination from the north and west. There is no natural attenuation in a fractured system. Any malfunctioning septic system, improper disposal, mishandling of waste at the nearby horse farm or spill on any property has the potential to impact the drinking water well of other residents to the south, southeast or east. There is no guarantee that the water will remain uncontaminated so I need to monitor it regularly as well as keep an eye out for likely sources of contamination. I have continued to test my water well at least once a year using much more affordable options that are available.

The Prince William County Service Authority, PWSA, provides public drinking water to various communities in Prince William County through several public supply systems one of which is the Bull Run Mountain and Evergreen System supplying those communities, our nearest neighbors. The Bull Run Mountain and Evergreen Water System is supplied from eight deep-drilled rock wells located throughout the water system in the lower part of Bull Run Mountain south of us but also part of the northwest portion of the Culpeper Basin. The PWSA describes the groundwater in this area as rated as high for susceptibility to contamination. “These ground water sources are constructed in an area that tends to promote migration of contaminants with land use activities of concern…within a 1000-ft radius of the well site.” Like all public water supplies the Bull Run Mountain and Evergreen Water System is required under the Safe Drinking Water Act, SDWA, to test their water monthly for compliance. I review their reports to track the northwestern Culpeper Basin water quality.

Under the SDWA, the Environmental Protection Agency, EPA, sets standards for 91 contaminants in drinking water including bacteria and disinfection by products. 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 and meet these minimum standards. 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 91 contaminants is a lot, there are approximately 80,000 chemicals in use in our society and an uncounted number of pathogens and while monthly testing is required, only bacterial contamination is tested each month the other contaminants are tested over a longer time frame in the Bull Run Mountain and Evergreen System. Nonetheless, the water quality has remained consistently good during the past year.

Though a couple of the public supply wells are filtered for sediment removal, the PWSA states in their annual report of water quality. “We are proud to be one of the few Virginia community water systems that do not require disinfection treatment. The Bull Run Mountain and Evergreen Water System is Virginia’s largest non-chlorinated community water supply. We pride ourselves with having pristine natural source waters. Most wells are dosed with sodium hydroxide to raise the pH and reduce the water’s natural corrosiveness.” The public supply homes and businesses are receiving water directly from the groundwater source with a little sodium hydroxide added to neutralize it. That is a verification of the base water quality. My well draws from under 100 feet below grade and has consistently tested at neutral pH every year. I do not treat my water, when I examine the analysis each year I have seen no need for any treatment.

Routine testing has shown that the natural source waters in the northwest portion of the Culpeper Basin are pristine. The only way to know if your water is good water or bad water is to test it. 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. Do not rely solely on water treatment salespeople for water analysis. The tests they perform are often crude and sometimes misleading. They are selling water treatment. The Virginia Household Water Quality Program subsidizes the analysis cost for private drinking water well clinics in a few counties each year. In 2012 Prince William, Loudoun, Frederic are among the counties that will have clinics. The analysis offered by the state program now includes: total coliform, E. Coli, sulfate, nitrate, fluoride, copper, lead, arsenic, hardness, total dissolved solids, pH, manganese, iron, sodium and is estimated to cost $55 for each household. Take the time to attend the clinic and test your water. You can save $100-$200 and get free help in interpreting the results. Join us and know the quality of your water.

Low Impact Development and Why it Matters

It has been called green infrastructure, conservation design, sustainable storm water design, natural stormwater management, and rain management but Low Impact Development, LID, seems to be the term that has taken hold in the United States for the site level actions and strategies. LID is a strategy of stormwater management emphasizing conservation and natural features combined with small scale stormwater controls to mimic as closely as possible the natural hydraulic properties of a site. The idea is to move water slowly through open conveyance systems and use distributed stormwater retention in open unpaved areas to allow infiltration of rain water into the earth. This reduces the quantity and velocity of stormwater as it leaves a site reducing the damage that uncontrolled stormwater runoff can cause when we change the amount of impervious surfaces a site has by building roads, sidewalks, playgrounds, and structures and compacting soil.

Traditional development practices cover large areas of the ground with impervious surfaces such as roads, driveways, sidewalks and buildings. These paved and impervious surfaces prevent rainwater from infiltrating into the ground, causing it to run off site at velocities and volumes that are much higher than would naturally occur. The collective force of such rainwater scours streams erodes stream banks resulting in large quantities of sediment and other pollutants entering streams, rivers, estuaries and bays every time it rains or snow melts. The US EPA believes that sediment and nutrient pollutions contained in runoff from urban areas is the largest source of water quality impairments to estuaries (areas near the coast where seawater mixes with freshwater) in the United States and has turned its water quality focus on these areas starting with the Chesapeake Bay Watershed and moving forward with the Gulf Coast estuaries.

Groundwater is recharged from rain and sources of surface infiltration. In many areas where development has occurred, we pump the groundwater for drinking water supplies (both public and private) and create barriers to rain infiltration by paving significant portion of the urban and suburban landscape as well as allowing if not encouraging storm water to leave a site as quickly as possible reducing the time that rainwater has to infiltrate the remaining soil and percolate into the subsurface. If we do not allow adequate rain water infiltration we will deplete the groundwater aquifers as we continue to pump water from wells. The U.S. Geological Survey’s (USGS) Groundwater Resources Program has found that the volume of groundwater stored in the earth is decreasing in many regions of the United States, and if this continues we could deplete our groundwater. We are running a groundwater deficit in many parts of our country, though we have adequate rainfall. LID can help by increasing water infiltration and reducing runoff.

In addition to the problems caused by stormwater and non point source runoff, many older cities (including many of the largest cities in the United States), have combined sewage and storm water systems which results in the storm water runoff overflowing the combined sewer system during storm events and diluted, but nonetheless raw sewage being released to rivers and estuaries. This is an ongoing problem in Baltimore and at Blue Planes in Washington DC as well as other cities throughout the nation. In the late 20th century, most cities that attempted to reduce sewer overflows did so by separating combined sewers, expanding treatment capacity, expanding storage within the sewer system, or by replacing broken or decaying pipes. San Francisco and many other cities have taken all of these steps, but still have much more that needs to be done. It is unfortunate that more of the stimulus dollars were not spent to repair expand and improve the waste water treatment facilities in our oldest cities instead of pursuing $54 billion in direct loans and loan guarantees to green energy companies. Repairs and improvements to our waste water treatment systems would have served our nation for several generations rather than been wasted on unproven technology or enriching favored entrepreneurs.

Managing rain water and snow melt is at the heart of LID. Rain water and storm water management under LID is landscape based and not particularly new. At the larger regional or watershed scale, green infrastructure is the interconnected network of preserved or restored natural lands and waters that provide essential environmental functions. Large-scale green infrastructure may include habitat corridors and water resource protection. At the community and neighborhood scale, green infrastructure incorporates planning and design approaches such as compact, mixed-use development, parking reduction strategies and urban forestry that reduces impervious surfaces and creates walkable, attractive communities.

At the site scale, green infrastructure is LID and mimics natural systems by utilizing permeable surfaces to absorb storm water back into the ground (infiltration), using trees and other natural vegetation to convert it to water vapor (evapotranspiration) and using rain barrels or cisterns to capture and reuse storm water. These natural processes manage storm water runoff in a way that maintains or restores the site’s natural hydrology, allowing groundwater to recharge. Site-level green infrastructure is LID, and can include rain gardens, porous pavements, green roofs, infiltration planters, trees and tree boxes and rainwater harvesting for non-potable uses such as toilet flushing and landscape irrigation. LID not only reduces the velocity and quantity of runoff protecting our streams, rivers, lakes and estuaries, it is essential to allow the recharge of groundwater.

The difficulty with LID is compliance and maintenance. Federal Clean Water Act requirements, such as the Combined Sewer Overflow (CSO) Control Policy and National Pollutant Discharge Elimination System (NPDES) permit program, do not allow for deviance from traditional control strategies. EPA guidance which encourages LID and green infrastructure to manage storm water is inconsistent with permit requirements under NPDES that call for more conventional methods of stormwater management.
NPDES regulations require development and implementation of a municipal separate storm sewer system (MS4) program to address post-construction runoff from newly developed and redeveloped areas. Investments in stormwater management and wastewater treatment plants are driven by compliance with regulations, which do not allow local policy makers to implement watershed-based or decentralized LID infrastructure solutions that may not yet have the data necessary to demonstrate performance and receive regulatory credit under a permit. Within the Chesapeake Bay Watershed the Chesapeake Bay Model provides credit under the Watershed Implementation Plans for LID retrofits, but not all practices are credited appropriately (both because of the amount of time needed for these practices to show long-term performance, as well as limitations in historic data collection). LID is by its nature a distributed design involving, rain gardens, porous pavements, green roofs, planters and rainwater harvesting require ongoing maintenance of the plants, replanting after severe winters or prolonged droughts, weeding, and clearing of porous pavements. There does not yet exist a method of ensuring that these features are maintained appropriately to continue functioning over time and that any repairs or replacements are done with LID in mind.