You Can Fix a Well with E Coli

If you find E colie or fecal coliform in your well the first step you should take is to protect your health then try and identify the source of the E coli and eliminate it.

1. If the sample tests positive for E coli then the first thing to do is chlorine shock not only the well, but also the inside piping and any treatment equipment to disinfect your home. 
2. Retest the water after the chlorine has left the system in about 10 days to two weeks see if E coli is present. 
3. If your well water tests positive again for total E coli, then the water must be treated to make it safe for consumption, while the source of is identified and eliminated if possible. 

Possible sources of E. coli contamination are septic tanks leaks, septic leach field or system failure, animal manure storage systems or in some areas with installed sewer systems and wells, sewer pipe leaks. There are instances when a neighborhood is hooked up to sewers, some of the homes do not pump out the old septic tanks and years later are found leaking.

Shallow groundwater is most easily contaminated by septic leaks, septic system failures, animal waste and sewer leaks. Nonetheless, in certain geology shallow sources of contamination can find their way into deeper groundwater. In fractured rock systems with limited overburden like we have here in the western portion of Prince William county, a fracture can carry contamination to deeper groundwater and spread the contamination.

Very shallow groundwater wells- dug or bored wells often become contaminated when the shallow aquifer becomes contaminated. These types of are prone to go dry during droughts and because they are shallow (less than 40 feet deep) are more subject to pollution. Drilled wells have more protection since they are more than 40 feet deep, typically more than 100 feet deep.

Well construction defects such as insufficient well casing depth, improper sealing of the space between the well casing and the borehole, corroded or cracked well casings, and poor well seals or caps can allow sewage, surface water, or insects to carry coliform bacteria into the well.

To prevent contamination to a well, regulations in Virginia and several other states have specified well construction standards since 1992. To provide the best natural protection these regulation require that the well should be 100 feet from the nearest edge of the septic drainfield and 50 feet from the nearest corner of the house. If the land area is small, the way to accomplish this is to separate the two as far as possible, with the septic drainfield downgradient of the well and go deep with the well. Obtaining the needed separation with vertical distance.

In Virginia (and most places) if a well is more than 100 feet deep the septic leach field need be only 50 feet away, but there are many wells like mine that have more than one water level and the shallower one is less than 100 feet deep (in my case 46 feet) making the well much more susceptible to contamination for the septic effluent leaching into the ground. You must make sure that the well is lined, grouted and the geology protects you from the drainfield to protect the well from the shallow ground water and being impacted by the septic system.

Septic drainfields also have a limited life. The life of a septic drainfield is dependent on how the system is managed, the frequency of septic tank pump outs, and the number of people living in a house, but 25-30 years is the typical life of those systems. After decades of use a septic drainfield can become a long term source of fecal or E coli contamination

Fecal coliform is the group of the total coliform that is considered to be present specifically in the gut and feces of warm-blooded animals. E. coli is considered to be the species of coliform bacteria that is the best indicator of fecal pollution and the possible presence of pathogens.

Back in the day we always recommended that a well that was contaminated with E coli be replaced with a new well. That is not always possible or desirable. I have observed several instances where E coli was eliminated from a well after repair of a failing septic system, but that takes time; so in the meantime the water must be treated to make it safe for consumption. Replacing a well can cost between $10,000 and $20,000, and cannot always be done.

Continuous disinfection of the water is necessary to protect you from fecal bacteria and E. coli. This is easily accomplished by installing either a UV (ultra violet) light or chlorine disinfection system. Your choice of systems should be based on personal preference and what other contaminants are present in your water. Both UV light and continuous chlorination do a good job of killing coliform bacteria including fecal coliform and E coli. However, chlorine treatment will control nuisance organisms such as iron, manganese, iron and manganese reducing bacteria and sulfate-reducing bacteria. Chlorine in water at the concentrations used for treatment is not poisonous to humans or animals. However, chlorine can impact the smell and/or taste of water even in very low concentrations. Household chlorination systems often use higher chlorine concentration than the typical 0.3 - 0.5 ppm (parts per million) concentration used for chlorination of public water supplies because the contact time is much shorter in home systems. UV light systems require filtration before the UV light maximize the functioning of the UV light system.

Both UV light and chlorine disinfection require additional treatment. Neither method of disinfection kills Giardia or Cryptosporidium, two microscopic parasites that can be found in surface water and groundwater that has been impacted by sewage. Both parasites produce cysts that cause illness and sometimes death. Giardia are often found in human, and dog feces. Cattle feces appear to be the primary source of Cryptosporidium, although these parasites have also been found in humans and other animals. Membrane filtration is the usual treatment for these parasites- a one micron or smaller membrane is required for this. There are new filter systems that combine carbon and one micron or smaller membrane a a special filter designed for this purpose.

Many manufacturers make whole house filters, typically they make a casings in 10, 20 or 30 inch and make different cartridges to address the various problems. To ensure that a filter removes Cryptosporidium, you can look for "NSF 53" or "NSF 58" and the words "cyst reduction" or "cyst removal." Reverse osmosis can also accomplish parasite removal, but typically only treats one sink rather than a whole house, wastes a lot of water, and if your water is at all hard requires a water softening system.

Fauquier County Water Issues

At the last meeting of the Potomac Watershed Roundtable Paul McCulla, County Administrator of Fauquier County Virginia, spoke about the water situation in Fauquier County. The following is drawn from his talk.

The town of Marshall in Fauquier County Virginia has water troubles as does other parts of the county. Recently drilled water wells in Marshall have either been low-yielding or had contamination that made the water unusable for human consumption forcing the service district to take three of their seven wells out of service. The Marshall wells were contaminated with radium, iron and manganese (all natural contaminants in parts of Virginia), volatile organic compounds (solvents), and e coli bacteria.

Fauquier County is organized on a “service district” model with public water and sewer provided in the nine urbanized areas of the County while the remainder of the County is semi-rural and agricultural with private supply groundwater wells and septic. Marshall located north of Route 66 is the northern most of the service districts. Fauquier County relies solely on groundwater for the County’s water needs- the public water supply is drawn from ground water wells.

The County’s comprehensive plan adopted in 1992 contemplated a mixed system of groundwater and surface water impoundments. The plan designated 9 separate reservoirs that would provide more than 24 million gallons of water per day in the nine service districts. However, after building only the combined Warrenton Lake and Airlie Reservoir the county Board of Supervisors determined that the county would rely solely on groundwater for their drinking water needs. The Warrenton Lake and Airlie Reservoir can provide 2.0 million gallons a day of water.

The nine service districts are spread across the County’s 651 square miles and in one of the County’s three geological provinces, the Blue Ridge Anticlinorium, the Culpeper Basin and the Piedmont Province. Each province has a separate propensity for groundwater retention. Most of the county groundwater is in fractured flow systems. The water availability is highly variable from one location to another in a fractured flow system and these systems have a high degree of susceptibility to surface water contamination. A contaminant can catch a fracture and be carried to the groundwater. These fractured flow systems are strongly influenced by surface conditions that can affect their recharge and contamination and thus have a high probability of changing over time. According to the U.S. Geological Survey fractured flow groundwater systems are challenging to understand and costly to manage.

Groundwater supply wells in the Marshall, Bealeton and Warrenton Service Districts have seen man-made contamination requiring millions of dollars in remediation efforts to continue to use the wells. In addition, there are water supply problems. During the earthquake of 2011 one public water supply well in the County’s Bealeton Service District lost ½ of its capacity due to a shift in the subsurface geology.

In Marshall the current drinking water capacity is no adequate. Currently, the communities four wells produce 0.217 million gallons per day. The water needs for the service district if all the land were developed to its current zoning would be 0.764 million gallons per day. However, if the current land use plans were all built out the water demand would be 1.268 million gallons a day –six times the current water capacity.

Based on total current and future groundwater use, the available recharge through rain and snow melt and potential threats to groundwater quality from contamination, Fauquier has identified a need for a groundwater management, protection and monitoring program and some immediate water supply solutions to ensure the availability, quality and sustainability of water to all Fauquier residents. This winter the service authority in Marshall is connecting a recently drilled well outside the town limits on an old farm. This well will produce up to 0.18 million gallons a day and will help alleviate the current water crisis.

Radium in Mid-West Groundwater

Since the 1950’s it has been known that groundwater from the Cambrian-Ordovician (C-O) aquifer system contained radium (Ra 226 and Ra 228) at concentrations that frequently exceed the US Environmental Protection Agency (USEPA) safe drinking water maximum contaminant level (MCL) of 185 mBq/L; 5 pCi/L. This aquifer provides more than 630 million gallons of water a day for public supply to parts of Illinois, Iowa, Michigan, Minnesota, Missouri, and Wisconsin. In addition, more than half a million people get their drinking water from private wells that tap the Cambrian-Ordovician aquifer.

A newly published U.S. Geological Study, part of the USGS National Water Quality Assessment Project, investigated the conditions that cause these unusually elevated levels of radium in the groundwater from the Cambrian-Ordovician aquifer. Knowing where and how much radium is in groundwater is important because of the health risks associated with drinking water that’s high in radioactive isotopes. Known health risks include an increased incidence of bone cancer and leukemia.

The USGS examined several variables like groundwater age, dissolved minerals, and dissolved oxygen levels in 80 samples collected across the six states. The researchers were able to better understand the conditions that cause radium to leach from the underlying geology into groundwater at higher levels.

They found that water that was recharged into the aquifer long ago, that contains greater amounts of dissolved minerals, and that is low in dissolved oxygen is more likely to leach radium from its surrounding rock. The estimated mean groundwater ages ranged from 19 years to more than 1 million years. Only eight samples had groundwater recharged since about 1950. The USGS found that more than 80% of the groundwater was older than 1,000 years. They also found that the proportion of the three Ra isotopes differed between the regionally unconfined and confined areas of the aquifer system.

Increased concentrations of Ra 226 was found in confined regions of the aquifer. The rate of groundwater flow in the confined area of the aquifer is very slow because relatively stagnant saline water restricts the movement of freshwater into deeper parts of the basins. Total Radium concentrations were significantly lower in HCO3 dominated, oxic samples from the unconfined area of the aquifer as compared to SO4 or Cl dominated, anoxic samples from the regionally confined areas.

Measured concentrations of all three Ra isotopes were significantly correlated with mean groundwater age reflecting the increased mobility of Ra with increasing mineralization and Fe-reducing conditions. The development of anoxic, Fe-reducing conditions and increasing water mineralization with groundwater age favors the mobilization of Ra and results in the frequent occurrence of Rac concentrations greater than 185 mBq/L (5 pCi/L) in the regionally confined area of the aquifer system. Under anoxic, Fe-reducing conditions, Fe- and Mn-hydroxides are dissolved, thereby reducing the adsorptive capacity of the aquifer solids.

No testing was done of the relatively shallower private drinking water wells. These well owners might consider having their water tested for radium as part of their regular well maintenance.

Arsenic in Your Well Water

A new study from the U.S. Geological Survey and Centers for Disease Control and Prevention was released last month. The author estimates that about 2.1 million people in the U.S. may be getting their drinking water from private domestic wells considered to have high concentrations of naturally occurring arsenic, presumed to be coming primarily from rocks and minerals through which the water flows.

About 44 million people in the lower 48 states use water from domestic wells,” said Joe Ayotte, a USGS hydrologist and lead author of the study. Private wells are the dominant source of drinking water for people living in rural parts of the United States. In most of the U.S., domestic well water quality is not regulated; it is up to the well owner to understand the arsenic hazard and other water quality hazards and take steps to test their water and treat it if necessary. This study is a good reminder that prudent, routine testing of the water is an essential first step for these homeowners and their families.

Using water samples from more than 20,000 domestic wells, the researchers developed a statistical model that estimates the probability of having high arsenic in domestic wells in a specific area. The researcher used a standard of 10 micrograms of arsenic per liter -- the maximum contaminant level allowed for public water supplies and used it developed maps of the contiguous U.S. showing locations where there are likely higher levels of arsenic in groundwater, and how many people may be using it. They used that model in combination with information on the U.S. domestic well population to estimate the population in each county of the continental United States with potentially high concentrations of arsenic in domestic wells.

Much of the country is potentially impacted by arsenic and is a national public health concern. Some of the locations where the authors estimated the most people have high-levels of arsenic in private domestic well water include:

• Much of the West – Washington, Oregon, Nevada, California, Arizona, New Mexico
• Parts of the Northeast and Midwest – Maine, Massachusetts, New Hampshire, New Jersey, Maryland, Michigan, Wisconsin, Illinois Ohio, Indiana
• Some of the Atlantic southeast coastal states – Florida, Virginia, North Carolina, South Carolina

Long-term exposure to arsenic in domestic wells may cause health-related problems, including an increased risk of cancer. Recent work in the U.S. also indicates that low-level arsenic may impact fetal growth and may be related to preterm birth. Public water supplies are regulated by the U.S. EPA, but maintenance, testing and treatment of private water supplies are the sole responsibility of the homeowner. Though about 44 million people in the U.S. get their drinking water from private wells, surveys indicate many homeowners are unaware of some basic testing that should be done to help ensure safe drinking water in the home.

Like may other contaminants, high concentrations of arsenic in water do not effect taste or smell, the only way to know how much arsenic is in drinking water is to have it tested. Testing you well is the first step in ensuring the safety of your drinking water supply. After testing it may be necessary to treat the water to reduce or eliminating the health risks or concerns.

You may wish to consider water treatment methods such as reverse osmosis, ultra-filtration, distillation, or as a last choice ion exchange. Typically these methods are used to treat water at only one faucet. Though anionic exchange systems (water softeners) are whole house systems, they may not be the best choice. These systems use a physical/chemical process to exchange ions between a resin bed and water passing through. These systems can remove calcium carbonate, iron and manganese, and lower nitrate and arsenic levels. Specific contaminant removal is determined by the composition of the resin bed used. Other constituents in water can compete with arsenic for the resin sites reducing the systems effectiveness. Also, depending on your water chemistry, they may create other problems.

To understand the risk and to make progress on reducing exposure in a systematic way, we need better understanding of groundwater chemistry and estimates of the population affected by high arsenic concentrations and other contaminants. The work by the USGS and the Virginia Household Quality Program accumulates data and helps homeowners identify these risks.

Is My Groundwater Being Used Up?

I breathed a big sigh of relief when the rains came last week. I live in the northwest corner of Prince William county that is often shielded from rain; it can be pouring 5 miles down the road in Haymarket and dry here. Earlier this month the groundwater level in the U.S. Geological Survey (USGS) monitoring well up the road from my home recorded its lowest level in 86 years and I began to worry about my water supply. Now, water levels have crawled back up to the 10th percentile and I am watchful but not worried.

Groundwater is water beneath the surface of the earth. It is one of our Nation's most important natural resources and is often taken for granted. According to the U.S. Geological Survey (USGS) groundwater is the provides 38% of public water supplies in our country. In addition, groundwater is the sole source of drinking water for more than 97% of the rural population who are not connected to city or community water systems. I am one of the 46 million Americans who depend on a private well for their water, so I care very much about groundwater, its sustainability and its protection.

My well draws on an unconfined aquifer. A water-table, or unconfined, aquifer is an aquifer whose upper water surface (water table) is at atmospheric pressure, and thus is able to rise and fall with moisture that is contained in the earth. Water-table aquifers are usually shallower than confined aquifers are. Because they are shallow, they are impacted by drought conditions much sooner than confined aquifers. A confined aquifer is an aquifer below the land surface that is saturated with water. Layers of impermeable material are both above and below the aquifer, causing it to be under pressure so that when the aquifer is penetrated by a well, the water will rise above the top of the aquifer.

The water level in the aquifer that supplies a well does not always stay the same. Droughts, seasonal variations in rainfall, and pumping affect the level of the water table. If a well is pumped at a faster rate than the aquifer around it is recharged by precipitation or other underground flow, then water levels in the well can fall. This is what happens during times of drought and happened this summer when there was little or no rain in our little micro-climate. A well is said to have gone dry when the water level falls below the pump intake. This does not mean your well will never have water in it again, as the water level may come back through time as recharge increases. If drought has caused the water level to fall, then precipitation can restore the well.

There are other forces that can impact the recharge of a well. Land use changes that significantly increase impervious cover and stormwater velocity can prevent water from soaking into the earth and reduce recharge of the groundwater making existing wells more susceptible to drought. Significant increases in groundwater use for irrigation of crops or playing fields, or commercial or industrial purposes can overtax and aquifer and dry out neighboring wells. Unless there is an earthquake or other geological event groundwater changes are not abrupt and problems with water supply tend to happen slowly as demand increases with construction and recharge is impacted by adding paved roads, driveways, houses and other impervious surfaces.

The water level in a groundwater wells naturally fluctuates during the year. Groundwater levels tend to be highest in the early spring after winter snowmelt and spring rainfall when the groundwater is recharged. Groundwater levels begin to fall in May and typically continue to decline during summer as plants and trees use the available shallow groundwater to grow and streamflow draws water. Natural groundwater levels usually reach their lowest point in late September or October when fall rains begin to recharge the groundwater again. It is concerning that the monitoring well recorded its lowest level in 86 years.

The natural fluctuations of groundwater levels are most pronounced in shallow wells that are most susceptible to drought. Older wells tend to be shallower. However, deeper wells may be impacted by an extended drought and take longer to recover. My well is fairly shallow in a fractured rock system with little overburden. During dry periods, I can watch the water level fall. The chart below is from a nearby USGS monitoring well.

Private wells draw their water from groundwater. Geology, climate, weather, land use and many other factors determine the quality of the groundwater; and the water level in your well depends on a number of things, such as the depth of the well, the type (confined or unconfined) of aquifer the well taps, the amount of pumping that occurs in this aquifer, and the amount of recharge occurring. Within Prince William County Virginia there are four distinct geologic provinces: (1) the Blue Ridge, (2) the Culpeper Basin, (3) the Piedmont, and (4) the Coastal Plain. The northwestern part of Prince William County down the hill from Bull Run Mountain, consists of sedimentary rocks of the Culpeper Basin. The predominant rock types are conglomerates, sandstones, siltstones, shales, and argillaceous limestones. This geology tends to have moderate to excellent water-bearing potential because it is a fractured rock system with very little overburden. The highest reported yields in the county are from wells in this geology.

It is concerning that the seasonal lows are getting lower. This is a sign that the present groundwater use is not sustainable. Since we do not know what the total available water is, it is impossible to know how critical the overuse or diminished recharge of the aquifer is. According to studies by a group of researchers at the University of California, Irvine, the University of Texas, and the Hydrological Sciences Branch at NASA GSFC using satellites to perform real world groundwater monitoring Virginia’s aquifers are under stress. That means that we are using up the groundwater faster than it is recharging. That is exactly what an 86 year low level of groundwater is telling us.

VDH Tests the Wells on Possum Point Road

Last winter after initially offering the service for around $1,200 the Virginia Department of Health (VDH) decided to sample and analyze at the Department’s expense the private drinking water well of any of the 24 homeowners adjacent to the Dominion Power Possum Point Plant. This is the Prince William County power plant where Dominion Power has been moving forward with a plan to “close in place” 3.7 million cubic yards of coal ash under the new U.S. EPA Coal Ash regulation. The plan for Possum Point is to consolidate all of the on-site coal ash into one impoundment. Dominion has collected more than 1 million cubic yards of ash from four smaller ponds; put them into the large 120-acre pond that already contains 2.6 million cubic yards of coal ash that they have begun to dewater. Ultimately, the pond will be capped with an impermeable membrane to prevent future infiltration of rain.

However, these coal ash ponds have been open to the elements and taking on water for decades. There is concern that trace contaminants and metals in the coal ash may have already leached into the groundwater, Quantico Creek and Potomac, though the residential wells are all up gradient (the groundwater naturally flows to the bay) of the coal ash ponds and separated by an tributary known to the residents as “Beaver Pond” which would under most circumstances act as a hydraulic barrier between the coal ash ponds and the residences. In other words the hydrology of the area would tend to act to protect the homeowners’ wells from contamination for the power plant. In addition, groundwater in Prince William County tends to be very “young” depending on the depth of the well.

Our modern world is filled with chemicals, they exist in pharmaceuticals, household products, personal care products, plastics, pesticides, industrial chemicals, human and animal waste and yes coal ash ponds; 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. Under the authority of the Safe Drinking Water Act (SDWA), EPA sets standards for approximately 91 contaminants in drinking water including bacteria from human waste, industrial discharge streams and water disinfection by-products and distribution system contaminants. For each of these contaminants, EPA sets a legal limit, called a maximum contaminant level (MCL). 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.

While the U.S. Environmental Protection Agency (EPA) regulates public water systems, making the imperfect United States public water systems the safest and cleanest on earth there are no regulations for private drinking water wells. The responsibility for ensuring the safety and consistent supply of water from the estimated more than 21 million private wells belongs to the well owner. These responsibilities should include knowing the well’s history, testing the water quality annually (or more often as needed), and having the well system and its components inspected regularly by a well driller licensed or certified. In Virginia that is the Department of Professional and Occupational Regulation, DPOR. Regulations for wells in Virginia have only been in effect since 1992 and only address the construction of the well not the safety or quality of the groundwater. However, there are no regulations in Virginia to make you test or care for your private well. Most home owners do not test their wells. Though there are reported to be 1.5 million Virginian who depend on a private well for their drinking water, the Virginia Rural Household Water Quality program that subsidizes the costs tests less than 1,500 wells a year, and only 6 of the 24 well owners on Possum Point Road chose to have VDH test their wells.

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 defines a contaminant as “any physical, chemical, biological, or radiological substance or matter in water.” 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. Drinking water contains much more than just the water molecule, there are minerals and metals and traces of many other substances. One of the more surprising facts about water is that all the water on Earth is about 4.5 billion years old, dating form when the earth was formed.

Slowly, the waters of earth have picked up traces of its journey through time and the planet. However, the SDWA only has MCLs and secondary standards for 91 contaminants that have been found to impact many public drinking water systems. Some substances have non-regulatory human health screening levels and then there are substances where no screening level has been determined. 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.

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, though most contaminants in water are naturally occurring, 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.

Only 6 of the 24 homeowners on Possum Point Road were interested in having their water wells tested by the VDH. The methodology used by the VDH was different from what we do when we sample in the Rural Household Water Quality Program because our purposes are different. Our program is interested in identifying bacterial contamination, matching water quality to household treatment options and measuring the impact of the household plumbing on the drinking water. Our methods are designed for that and require a fist draw for our water clinics. This year our clinic’s samples were analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, and copper, total coliform bacteria and E. coli bacteria. These are mostly the naturally occurring contaminants and common sources of contamination: a poorly sealed well or a nearby leaking septic system, or indications of plumbing system corrosion.

The VDH was looking to take water samples that represent the underlying aquifer. The wells were sampled by the health department on three different days; on February 23rd 2016 (1 well), March 1, 2016 (4 wells) and March 7th 2016 (1 well). All the wells were sampled from an outdoor spigot or tap before treatment close to the well head after purging 20 gallons (in one instance), 40 gallons (in 4 instances) or 44 gallons (in one instance). The goal was to test the underlying aquifer not the impact to water sitting in pipes for several hours. While this method would likely reduce impact from piping, it is unlikely that flushing 20-44 gallons would flush the water from the well column so the lead they found present in the 4 wells with acidic water was likely from the well and pump fittings which historically have contained up to 8% lead in the brass. Well columns contain (typically) about 1.5 gallons per foot so it is most likely that the VDH was sampling water that had been stored in the well for an unknown period of time.

This brings up a weakness in the information. There is no information provided about the wells themselves. The type, age, depth of the well, and the recharge rate are unreported. Four of the six wells had water that was slightly acidic and though the flushed water samples from the point tested was below the MCL for lead of 15 ppb, as the VDH points out there are many who believe that there is no safe level for lead, especially since the VDH for the most part tested an outdoor spigot and did not measure the impact of the household plumbing to flushed lead levels. We find in our water clinics that elevated levels of lead often occur in homes with acidic water. While the presence of low levels of lead in the home with acidic water (a pH of 4.85-5.79) is of concern for long term health of the occupants, it is not an indication of impact from the Dominion coal ash ponds. This commonly occurs throughout the county and the Commonwealth. Other findings of concern were VDH discover that one of the wells had a large opening in its lid which presents a significant contamination risk for bacterial contamination as well as insects and small animals. Another well was reported to be in the basement of the home. This well does not meet the current state well construction regulations or the old 1979 county well regulations. Finally, there were significant elevations of sodium, sulfate, iron, and manganese substances that are naturally occurring and can make well water quite unpleasant.

The VDH tested the water for thirteen contaminants that are regulated under the Safe Drinking Water Act (arsenic, barium, beryllium, cadmium, total chromium, mercury, lead, antimony, selenium, thallium, radium). Though traces of various substances were found, none of the levels of contaminants were above the MCLs or SMCLs of the Safe Drinking Water Act so would be acceptable for public drinking water supplies. The VDH also tested for substances not regulated under the Safe Drinking Water Act. These contaminants were: boron, calcium, cobalt, lithium, magnesium, sodium, nickel, vanadium, zinc, alkalinity, bicarbonate alkalinity, carbonate alkalinity, hexavalent chromium, molybdenum, strontium, thorium, radium-228 and vanadium. The chart below shows the summary of results of what they found (you can request the information under the FOIA).

The Causes of Reduced Well Flow

If your household water is supplied by a well, responsibility for maintaining your water supply falls to you, and there are many potential causes of what seems to be a loss of water pressure or water volume. In a well, a diminished water supply or well yield can be caused by drop in water level due to drought or over pumping of the aquifer, the well could be failing or fouling or there might be an underlying well construction or design problem. There are also equipment problems that seem to mimic a failing well- a leak in the pitless adaptor or pipe to the house or a worn or damaged pump impeller could reduce well flow or water pressure. Remember that equipment problems are the most common cause of well problems. So let’s start there.

The essential components of a modern drilled well system are: a submersible pump, a check valve (with an additional valve every 100 feet), a pitless adaptor to bring the water to the house below the frost line, a sanitary sealed well cap to keep out vermin and bugs, electrical wiring including a control box, pressure switch, a pressure tank to literally push the water throughout the house and an interior water delivery system known as your plumbing. There are additional fittings and cut-off switches for system protection, but the above are the basics. To keep the home supplied with water each mechanical component in the system and well must remain operational.

A leak in the piping from the well to the house could reduce the well flow, a damaged pump or the components in the basement that provide consistent water pressure and the electrical switch that turns on the pump. Look for indication of moisture, and subsidence to find a leaking pipe between the well and the house. In the house water goes into the pressure tank. Inside the pressure tank is an air bladder that becomes compressed as water is pumped into the tank. The pressure in the tank moves the water through the house pipes so that the pump does not have to run every time you open a faucet. The pressure tank typically maintains the water pressure between 40-60 psi or 30-50 psi for smaller tanks. After the pressure drops below the cut in pressure (typically 40 psi), the electrical switch turns on the pump and the pressure in the tank increases as the tank fills. If however, the pump is not delivering water fast enough the pressure tank could fail to regain its head while the water is in use. Also, jiggle the tank to make sure that there is not a hole in the bladder and the area above the bladder is not filling with water and becoming water logged. Sometime just draining the pressure tank, bleeding the air out and recharging it will improve a situation, but like any mechanical piece of equipment pressure tanks do wear out.

from USGS

The well itself can also be the cause of reduced well flow. The well has a casing (a metal or plastic liner) that may extend the length of the well, or at least to the bedrock and then have some sort of slotted casing, screen or “sock” around the pump impeller to keep debris, sand and sediment out of the system. In Virginia, there have been well regulations in place since 1992 to prevent poorly designed and developed wells but, it still happens and there are still a huge number of wells that predate regulations.

If you are having a well drilled check to make sure that the well driller is licensed and that the well is built according to regulations (if your location does not have well construction regulations check the regulations in other states or provinces to make sure you get a quality well). Always use a local well driller with experience in your immediate vicinity, the type of well construction must be matched with the geology and the characteristics of the aquifer. Experience is often helpful (but not everyone is capable of understanding and learning from experience). An understanding of geology and hydrology, very local and detailed regulation, or enough experience of knowing what has worked before is essential when choosing between a perforated well casing or well screen, identifying the right size slotting or screening to use, the placement within the borehole of the screening or perforated liner, whether a sand pack is necessary and where to locate the pump in the well. Poor choices in any of these items could cause problems with excess sediment in your water or reduced well yield.

When you drill a well, mud and bore hole cuttings can partially plug the well. This material must be removed to allow water to freely enter the well during well development. A good well driller will do a better job of this, a less than good well driller will tell you that excess sediment in your new well needs a sediment filter and will happily sell you a new pump when the first one fails prematurely. Sediment does tend to reduce in the first year because not all of the cuttings are removed during well development. If the well has not been fully and properly developed, the well will often produce excess amounts of sediment or have a low water production yield. Though not every well drilled has the potential to provide enough water for a household (even in my water rich part of Virginia), poor choices in well completion design can render even a good well a poor producing well.

Groundwater supply can change because groundwater systems are dynamic. In the Valley and Ridge of Virginia (west of 95 and before the Appalachian Plateau) the geology is characterized by unconsolidated overlay underlain by fractured rock. In the Piedmont region the fractured rock tends to be sedimentary rock and is carbonate rocks within the areas of karst terrain. Fractured rock systems tend to be water rich areas of Virginia, but not uniformly so. In the fractured rock systems of the Valley and Ridge wells draw groundwater from fractures in the bedding plane which run parallel to the vertical fractures. Fractures can run dry or become encrusted. In unconsolidated sediments of the coastal plain ground water is pulled from the saturated zone, but the wells needs to be screened. In the Appalachian Plateau which is a flat layered rock system with horizontal fractures, the coal seams are typically the aquifer and groundwater is typically shallow. Coal country is the location of many shallower dug wells which easily go dry during times of drought.

While many well problems are caused by poor construction, development or operation of the well, the geology can also be a source of problems. Reduced well yield can be caused by lack of recharge. The water withdrawn from an aquifer can be increased by building homes and increased use for irrigation, domestic watering of gardens and/or reduced recharge. The more land area that becomes covered with pavement, and buildings the less water percolates into the ground and recharges the aquifer. If water is withdrawn from a well faster than the aquifer is able to produce, the well is over-pumped and that is reported to be the most common cause of premature well failure. Over-pumping not only depletes the groundwater, but it rapidly increases the rate of sediment drawn into the well by the pumps suction, causing plugging of the perforated area where water flows into the well. It can also cause corrosion, incrustation and biofouling or the aquifer to compact which further restricts water flow to the well.

Sometimes a decline in water level is seasonal or due to a drought. Typically water levels are higher in spring and lower in the fall. Extended dry periods can also impact water levels, especially in shallow aquifers supplying dug wells. Checking the water level in your well or a nearby proxy monitoring well is a way to identify water level trends and aquifer depletion before the problem becomes serious. If you have the opportunity to install a level monitor for your own well, it is a way to identify a failing well or diagnose a problem, but in most instances it is not practical. For years I have coveted a water level monitor (also a Viking stove- but I don’t have either).

Mineral incrustation is a common problem in some aquifers where there is an abundance of dissolved minerals including calcium, magnesium and iron, as well as iron bacteria. If you have hard water, you well can become encrusted when minerals precipitate or settle out during the pressure changes in the pumping process. This causes scale deposits on the casing, liner and screens. Over time incrustation can reduce the flow of a well. If you have scale formation within the well a well can be treated with chemicals or acid or in some geology gently hydraulically fractured. To do this “right” takes equipment and knowledge. There are well treatment specialists and lots of people who have no clue. Be award that an old metal casing may not survive chemical or mechanical treatment and the well may collapse.

Installing and pumping a well often introduces bacteria into the subsurface and increases the level of oxygen and nutrients in the well and surrounding aquifer. Naturally occurring bacteria, such as iron bacteria or sulfur reducing bacteria, may thrive under these conditions. Iron bacteria, sulfur reducing bacteria and related bacteria can form a gel-like slime that captures chemicals, minerals and other particles such as sand, clays and silts. "Biofouling" occurs when the accumulations of gunk are sufficient to reduce water flow through screens and slats or impair the pump. This can mean reduced well yield and water quality. Iron bacteria buildup is a problem that I have dealt with. A couple of years ago I chlorinated the heck out of the well (800 ppm chlorine- I kid you not). That single treatment has kept my house and hopefully my well iron bacteria free since. I keep an eye out for slime build-up on the toilet flappers and will treat the system again when necessary- before I have reduced well yield or pump damage.

It is important to understand what is going on with your well before you begin replacing pumps or drilling new wells. Sometimes it’s just a loose wire or a waterlogged pressure tank, other times you have much bigger problems.