Radionuclides in My Well Water- Now What Do I Do

A radionuclide is an atom with an unstable nucleus that emits its excess energy in the form of rays or high speed particles. Radioactivity, the release of the excess energy as gamma rays and high energy alpha and beta particles occurs when unstable elements give off the excess energy and particles to form more stable elements. The process by which an element changes from an unstable state to a more stable state by emitting radiation is called radioactive decay.
Gamma rays, alpha particles, and beta particles, which are given off by radioactive decay, have very different properties but are all ionizing radiation. Each form of ionizing radiations contains enough energy to break chemical bonds. The radiation can break bonds in DNA and RNA disrupting its function and potentially damage or destroy living cells. Alpha particles do not penetrate the skin but enter the body when alpha-emitters are in food, water, or air. While some beta particles are capable of penetrating the skin, beta emitters are more hazardous when they enter the body through food and water.

Radioactive elements are naturally present in rocks, soil, and water from trace amounts to dangerous concentrations depending on where you are. The occurrence of radionuclides in ground water is controlled primarily by the local geology and geochemistry of rock and the flow and age of the water. Research by the U.S. Geological Survey (USGS) found that the over time the concentration of a one radioactive element varied significantly from the same well. Migration and concentration of radionuclides depends on the amount of radioactive material in the bedrock, the moisture levels in the soil, groundwater circulation, and atmospheric pressure. Uranium, thorium, and radium can be highly mobile in groundwater and can move considerable distances and be re-deposited in soils or carried in the groundwater to the well. The isotopes of radium can enter the body through water, and some may be deposited in the bones and may over many years can result in an increased risk of getting cancer. Exposure to uranium in drinking water may result in toxic effects to the kidneys. Some people who drink water containing uranium over many years have an increased risk of getting cancer.

Variation in Radon concentrations over time from USGS

When dissolved in water, radionuclides are colorless, odorless, and tasteless, and typically cannot be detected by our senses, unlike many well water contaminants that cause an undesirable color, odor, or taste. Natural radioactivity in drinking water and its effect on human health have become a greater concern in recent years. The U.S. Environmental Protection Agency (EPA) has primary drinking water standards for gross alpha emitters, beta particles, radium and uranium under the Safe Drinking Water Act. However, the EPA also recommends that based solely on possible health risks and exposure over a lifetime that the goal should be to drink water containing a zero concentration of alpha emitters, beta particles, radium 226 and 228 and Uranium.

The EPA does not yet have a recommended drinking water standard for radon because the primary source of radon exposure is from breathing contaminated air in the home or office. EPA has focused on concentration of radon in the air. Radon is a colorless, odorless gas produced by the radioactive decay of radium, which in turn was formed by the decay of uranium. There is a correlation of elevated concentrations of radon in the inside air with elevated concentrations of radionuclidies in groundwater and groundwater can carry radon into the house.

Geological exploration has identified more than 55 locations within the Piedmont and Blue Ridge regions of Virginia where uranium is found. Uranium occurs in the Lovingston rock formation at a fraction of a percent, but radionuclides are known to be present in the groundwater in the regions thanks to sampling done at community water wells. About a decade ago, the USGS found that naturally occurring radionuclides in the ground water of southeastern Pennsylvania may pose a health hazard to some drinking water from wells drilled in the Chickies Quartzite. Counties in Maryland also have high radionuclides in water, just to name a few locations. You can find out more about the likelihood of radionuclides in your groundwater by inquiring at your state’s department of environmental quality or protection or by reading the community disclosure of nearby community water supply wells. That’s how I found out about local water quality and what to test for when I moved to this region.

If you are one of the 15% of U.S. households who obtain your water from a private well, you need to test your well. Every year you should test your well for bacteria and every few years for other substances including radionuclides. The radionuclides tests are expensive the cheapest way to go is to have a state and federal qualified and certified laboratory sample your well water for short-term GAPA, and GBPA. This screening test is less expensive than direct analysis for specific radionuclides. Testing for GAPA and GBPA may cost between $100 and $200, while testing for radium isotopes may cost between $200 and $300. Testing for total uranium may cost between $100 and $200. Call your local department of health to locate a qualified laboratory. Areas with known elevated levels of radionuclides tend to have a list of qualified laboratories. For a fee some health departments can sample your well. Nobody has the budget to test your well for free.

Once you identify the problem, solving the problem of radionuclides is very direct. The only real concern is drinking water and the possibility of radon carried in the water being released into the home. Reverse osmosis systems installed in the kitchen can be used to remove up to 99% of radionuclides in drinking water with selection of the correct membrane according to the EPA. Removal effectiveness depends on membrane selected, the water pressure and proper installation. Proper selection of the membrane and pressure is essential when selecting a reverse osmosis system. Hard water will cause scaling on the membrane so buy extra membranes and know how to change them. When the water pressure in the sink drops, the membrane is fouled and needs to be changed. The reverse osmosis systems require regular maintenance and monitoring to continue to function properly over an extended period of time.

Though I am not a fan of these systems in many applications, they are the best available technology for radionuclides. Reverse osmosis systems use a lot of water. They recover only 5% to 15% of the water entering the system, so they should only be used for the drinking and food preparation water. Waste water is typically connected to the house drains and will add to the load on the household septic system-it’s like adding an extra person to the septic load. A reverse osmosis system delivering 5 gallons of treated water per day may discharge 40 to 90 gallons of waste water per day to the septic system. This is a significant additional load and could impact the life and functioning of your septic system. You might want to look into other methods to dispose of the waste water.

Effectiveness of reverse osmosis system depends on initial levels of contamination, membrane size and type and water pressure. The application of pressure reverses the natural flow of the flow of water in osmosis from high concentration so that water passes from a more concentrated solution to a more dilute solution through a semi-permeable membrane. Reverse osmosis systems incorporate pre and post-filters along with the membrane itself in order for a reverse osmosis system to function properly. It is common to have a whole house filter system utilizing activated carbon installed in series with the reverse osmosis system. When addressing radionuclides the activated carbon filter can reduce the radon levels carried in the water, solving that problem.

Reverse osmosis units on the market range in cost from $200 to $3000 and vary in quality and effectiveness. Homes on well water need to purchase low pressure units. The size and membrane type are one of the factors that will determine cost. Replacement membranes cost $100 to $200 and filter cartridges around $50 (there are usually several)- it’s like a printer, the money is in selling the supplies. Reverse osmosis is a proven technology that has been used successfully on a commercial basis most famously for removing salt from seawater. Household reverse osmosis systems typically deliver small amounts (2 to 10 gallons per day) of treated water and waste 7 to 20 times the amount of water treated. Reverse osmosis systems can also remove many inorganic contaminants from household drinking water supplies including arsenic, sodium and nitrate. The removal effectiveness depends on the contaminant and its concentration, the membrane selected, the water pressure and proper installation and maintenance.

Radon in Your Home

Radon is a naturally occurring radioactive gas produced by the breakdown of uranium, thorium, radium, and other radioactive elements that naturally occur in granites as well as some metamorphic and sedimentary rocks in soil, rock, and water and is widespread in the United States.  According to the U.S. Environmental Protection Agency, EPA, radon is the second leading cause of lung cancer in the general population, and estimated to cause about 21,000 lung cancer deaths per year making it the leading cause of lung cancer in non-smokers. Like all environmental pollutants, there is some uncertainty about the magnitude of radon health risks. However, because estimates of radon risks are based on studies of cancer in humans (underground miners) we know more about radon risks than risks from most other cancer-causing environmental risks.

Radon is a colorless, odorless, radioactive gas derived from the decay of radioactive elements that naturally occur in granites as well as some metamorphic and sedimentary rocks. As radon gas is released from bedrock, it migrates upward through the soil and can seep into the basements of houses and other buildings through dirt floors, cracks in concrete, and floor drains. Radon has a tendency to accumulate in enclosed spaces such as buildings. Although areas of the country where Uranium concentrations are higher are more likely to contain higher radon levels, radon is a house specific issue. Even in an area of low radon potential a house can have elevated radon while neighbors’ houses have low radon levels. Migration and concentration of radon varies considerably, and depends on the amount of radioactive material especially uranium in the bedrock, the moisture levels in the soil, groundwater circulation, and atmospheric pressure. Uranium, thorium, and radium can be highly mobile in groundwater and can move considerable distances and be re-deposited in soils.

Air pressure inside your home is usually lower than pressure in the soil around your home's foundation. Because of this difference in pressure, your home acts like a vacuum, drawing radon in through foundation cracks and other openings. Radon, in its natural state cannot be detected with human senses- you cannot see, taste or smell it. The only way to detect radon is to test. Levels of about 0.4 picocuries per liter, pCi/L, of radon are typically found in the outside air. EPA recommends mitigating radon if the results of one long-term test or the average of two short-term tests show radon levels of 4 pCi/L or higher. According to the EPA, radon levels in most homes can be reduced to 2 pCi/L or below using standard mitigation techniques.  Most people only test their home at purchase, but the It is a good idea to retest your home if you make any changes to the structure and every few years to be sure radon levels remain low. In addition, if a radon mitigation system is installed it is important to monitor the system and retest at least every two years to make sure the system is functioning.

Yellow is low radon potential, orange is moderate radon potential and dark orange is high radon potential from DMME VA

Professional radon testers and mitigation contractors operating in the Commonwealth of Virginia and many other states can be found on the websites of the National Radon Safety Board  and the National Environmental Health Association . Radon contractors are not specifically licensed in Virginia, but many states require radon professionals to be licensed, certified, or registered, and to install radon mitigation systems that meet state requirements. Check with your local building department or the state department of health for the local requirements in your area. In 1986, the Virginia Department of Health, VDH, conducted a survey of 800 homes throughout the state and found that about 12 % had radon levels above the EPA’s recommended action level of 4.pCi/L. It would be reasonable to assume that radon probably is a significant problem in land overlying the regions of uranium deposits in Pittsylvania County and other areas of the Piedmont.

Radon mitigation takes one of two approaches either preventing the radon from entering the home or reducing the radon levels by dilution after the radon has entered the home. There are several techniques that can be used depending on the type of foundation the home has. According to the EPA it is better to prevent radon from entering the home in the first place so I will discuss the preferred methods of prevention. The type of foundation, construction materials and condition will determine the kind of radon reduction system that will work best. Homes are built with some kind of foundation- a basement, slab-on-grade, a crawlspace, or a combination of the three. It is common to have a basement under part of the home and to have a slab-on-grade or crawlspace under the rest of the home. In these situations a combination of radon reduction techniques may be needed to reduce radon levels to below  4 pCi/L.

Soil suction techniques are the preferred method of mitigation and prevents radon from entering your home by drawing the radon from below the home and venting it through a pipe(s) to the air above the home or outside the house where it is diluted by the ambient air. An effective method to reduce radon levels homes with crawl spaces is covering the dirt floor of the crawl space with a high-density plastic sheet. A vent pipe and fan are then installed and used to draw the radon from under the sheet and vent it to the outdoors. This is called sub-membrane suction, and according to the EPA when properly installed is the most effective way to reduce radon levels home with crawlspaces.

In homes with concrete slab foundations or basements, sub-slab depressurization is the most reliable radon reduction method. One or more suction pipes are inserted through the floor slab into the crushed rock or soil underneath the home and a fan is used to draw the radon from under the slab or basement floor to a roof or wall vent. It is possible, and in many cases preferable, to install the suction pipe under the slab by running the pipe on the outside of the house. Another variation is to use the drain tiles or perforated pipe that are installed in modern homes to keep basements dry. Suction on these tiles or pipes can be effective in reducing radon levels. This system is most effective if the drain tiles are on the inside of the footer, sealed beneath the floor and form a complete loop around the foundation of the building. In homes that have sump pumps the sump can be capped so that it can continue to drain water and serve as the location for a radon suction pipe. There are kits that can be purchased for capping the sump pump. It is important that the sump cover lid is readily removable for service of the sump pump.

There are several other techniques such as sealing cracks and passive methods that are often installed in new construction that are not as effective as active depressurization of the slab, basement or crawl space.  As a temporary measure ventilation will reduce the radon levels by introducing more outside air, but it will increase your heating and cooling bills. After a mitigation system is installed do confirmation testing of radon levels before you make the last payment to the contractor to ensure that the mitigation system works. For more information of mitigation approaches and techniques see the EPA’s Consumer's Guide to Radon Reduction .

Uranium Mining in Virginia a Threat to Our Water Resources

Last week the winter session of the Virginia General Assembly was called to order. Scheduled to be decided this winter is whether or not to lift a 30-year-old moratorium on uranium mining within the state. Senator John Watkins has introduced a proposal to require the state to draft uranium-mining regulations, essentially ending the 30 year moratorium on Uranium mining in the Commonwealth. Senator Watkins, from Powhatan and Senator Richard Saslaw, from Fairfax will carry the legislation in the Senate, and Delegate Jackson Miller, from Manassas, will introduce similar legislation in the House of Delegates. Now is the time to make your voice heard.

In 1978 a particularly rich deposit of Uranium was discovered at Cole's Hill in Pittsylvania County in south central Virginia. This was followed by a flurry of exploration for uranium deposits in Virginia. In 1982 the Commonwealth placed a moratorium on uranium mining. In recent years, as the price of uranium reached $140 around 2007, and two families living in the vicinity of Cole's Hill formed a company called Virginia Uranium, Inc. to begin exploring the uranium deposit once again. Though the uranium spot price has fallen to around $40, that is still more than twice the historical price, and Virginia Uranium and their supporters have called for the Virginia legislature to lift the uranium mining moratorium for now just on Cole's Hill. As this was all percolating in state politics, in 2009 the Virginia Coal and Energy Commission requested that the National Research Council convene an independent committee of experts to review all the literature and develop a report to identify the scientific, environmental, human health and safety, and regulatory aspects of mining and processing Virginia’s uranium resources. In addition, Fairfax Water commissioned a white paper on uranium mining and ended up with the Fairfax County Water Authority opposing uranium mining in Virginia and supporting the continuation of the moratorium on uranium mining in the Commonwealth.  

After reviewing these reports and as a voting member of the Potomac Watershed Roundtable I voted with the majority to maintain the moratorium on uranium mining. The Virginia Association of Soil and Water Conservation Districts with which I am also affiliated (through my volunteer work at the PWSWCD) also supports maintaining the moratorium. The Virginia Municipal League, the Virginia Association of Counties, the Virginia Farm Bureau, the Fauquier Water Authority, and local governments from Halifax and Virginia Beach, oppose lifting the ban. Last week Lt. Gov. Bill Bolling, who serves as the tie-breaking vote in the Senate if the vote falls to party lines (Sen Watkins is a Republican and Senator Saslaw is a Democrat so that does not seem likely), announced that he supports maintaining the moratorium on uranium mining. Let me tell you why I do not want to see the moratorium lifted at this time.

From the Fairfax Water White Paper

Geological exploration has identified more than 55 locations within the Piedmont and Blue Ridge regions of Virginia where uranium is found.  Uranium occurs in the Lovingston rock formation at a fraction of a percent.  In order for a uranium occurrence to be considered a commercially exploitable source of uranium ore, it must be of sufficient size, be at least 0.1% uranium to the other rock components in the deposit and be able to be mined and processed with current technology. So far only the uranium deposits at Cole Hill have been proven to meet these requirements. Even the “rich deposits” at Cole hill will produce 1,000 pounds of waste called tailing for every pound of uranium extracted. The waste, the mine tailings, is the problem.

There are several methods to mine and process uranium. The choice of mining method depends on the quality and quantity of the ore, the shape and depth of the ore deposit, the type of rock, and a wide range of site-specific environmental conditions. Because of the geology in the Commonwealth of Virginia, it is likely that only open pit or underground mining would be viable. While there are risks inherent in mining to worker the uranium miners would also face the additional risk of dust containing radiation.

After the millions of pounds of rock are removed from the ground by conventional mining methods, the uranium must be separated from the rock and minerals and other radioactive materials, impurities removed and yellowcake produced. Yellowcake is a concentrated form of uranium oxide made in a combination of crushing and/or grinding the rock and chemical processes to dissolve the uranium from the rest of the rock using acids or bases to leach the uranium from the rock dust. The yellowcake then needs to be separated, dried, and packaged. There is more than one type of processing and the choice depends on the nature of the uranium ore, the composition of the rock in the formation as well as environmental, safety, and economic factors. During uranium ore processing, several waste products are created, including tailings, leached residue and waste water. Tailings consist of everything that was in the ore except the extracted uranium. Tailings from uranium mining and processing operations contain radioactive materials remaining from the radioactive decay of uranium, such as thorium and radium as well as heavy metals also present in the rock. The real risks to Virginia are the risks of contamination to our water resources from the waste water and tailings. Uranium tailings are a source of radioactive contamination for thousands of years, and therefore must be controlled and stored carefully away from water which will erode and carry the radioactive materials into the ground and surface water.

Over the past few decades, improvements have been made to tailings management systems to isolate tailings from the environment. The long term effectiveness of these management systems has not been tested and uranium mining is typically carried out in arid environments. Virginia is subject to relatively frequent storms that produce intense rainfall. Natural events such as hurricanes, earthquakes, intense rainfall, or drought could lead to the release of contaminants into the waters of Virginia. It is questionable whether modern-engineered tailings containment could be expected to prevent erosion and surface and groundwater contamination for as long as 1,000 years. In Coles Hill alone the tailings waste will amount to over 118,888,000,000 pounds of pulverized rock with radioactive materials that can slowly leach into our groundwater through failure to prevent percolation of precipitation into the tailings containment or through accidents be released from impoundments to surface waters. Though Virginia’s rainfall averages 42 inches a year in past few years alone rainfall has varied from under 30 inches to a high of 82 inches of rain a year. Water is a great solvent and in Virginia it would seem impossible to keep such vast quantities of tailings permanently isolated from water.  

The only use for uranium is for weapons and nuclear powered reactors. The United States currently has 104 nuclear reactors in operation supplying about 20% of U.S. electricity, and in 2011 these reactors required 20,256 short tons of concentrated enriched uranium and this is not expected to change significantly in the future. In 2010, the United States imported 92 % of the uranium that it needed to fuel its nuclear power reactors. There appears to be adequate world supply for our limited number of nuclear power plants at this time. Uranium mining and processing represents unique risks to source water supplies from toxic and radioactive byproducts. The half-life of the uranium 238 and its isotopes is thousands of years. A containment failure will risk the groundwater and surface water supply of the Commonwealth, and for Cole's Hill will endanger the drinking water supply of Virginia Beach if there is a breach in containment. With current technology, the risk is too great.  The uranium will still be there when our knowledge of how to stabilize for hundreds of year the mine tailings increases to the point we can safely mine the uranium without endangering our water resources.

The formation the contains uranium in Virginia from Fairfax Water