Test Your Well Annually

Private wells are not regulated under the Safe Drinking Water Act; the homeowner is entirely responsible for monitoring water safety.  Many pollutants that can impact your health, such as Nitrates and E. coli, have no taste, smell, or color. An annual water test acts as a "health check-up" for your well, helping to identify problems early. The U.S. Environmental Protection Agency, the CDC, the Virginia Department of Health and various other organizations recommend annual testing, but most homeowners do not. There is no requirement in Virginia. I test my well every year, and the Virginia Household Water Quality Program run annually by the Extension Office is one of the cheapest ways to get it done.  Judging by the number of people who participate in the clinic each year (a hundred or so out of 16,000 of well owners in Prince William County) most people do not test their well regularly. You should.

 Last Wednesday morning following the instructions from the Extension Office, I collected water samples from my kitchen sink and put the sample bottles in the refrigerator. Then after having coffee and feeding the pets, I drove the samples (in an insulated lunch pack on ice) to the Extension Office in Manassas. Once a year the Virginia Cooperative Extension in Prince William County holds a well water testing clinic where water samples are tested for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria all for the low cost of $70. Though you missed the clinic this year, you can email    and get your name added to the notification list. Trish Westenbroek is doing an excellent job of coordinating the program and sending out reminders, so email PWestenbroek@pwcgov.org  and ask to be put on the list and you will get a notification next winter to sign up.

While the U.S. Environmental Protection Agency (EPA) regulates public water systems, the responsibility for ensuring the safety and consistent supply of water from a private well belongs to the well owner-in this case me. These responsibilities should include knowing the well’s history and planning for equipment replacement, 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 well-service company. 

In Virginia installation of private wells is regulated by the Department of Health, responsible for approving the location of a well, inspecting the well after construction to verify proper grouting and adequate water yield, maintaining records of the well driller’s log, verifying the most basic potability of water by requiring at a minimum bacterial testing after completion. Then you are on your own to do what you deem best.

If your home has a drinking water well that is contaminated, it could significantly impact your health and the value of the property. When you buy a home lenders require that a well be tested for coliform bacteria contamination, nothing more. For many homeowners this was the only time their well was ever tested. Total coliform bacteria is always present in manure and sewage, but is also present in soil and vegetation and surface water. The presence of coliform bacteria can mean that surface water is getting into the well either directly through a failing casing or grouting or improper construction or well cap or by other means. Absence of coliform bacteria only means that water is not contaminated by septic and surface runoff, but the water might be contaminated from other sources.

Due to its protected location underground, most groundwater tends to be clean and free from pollution. Typically, the deeper the well the less likely is it to be contaminated; however, there are a number of threats to drinking water: improperly disposed of chemicals (pesticides and oil poured down the drain of a home with a septic system); animal wastes; pesticides; human wastes (that nearby septic system); wastes buried underground or leaking fuel tank; and naturally-occurring substances can all contaminate drinking water and make it unsuitable for drinking or make the water unpleasant to drink. Homes built on former disposal sites- farm dumps, landfills or former military operations are particularly susceptible to contamination. Former agricultural properties should be tested for pesticides, fuels and solvents because farmers often have fuel tanks and repaired farm equipment with solvents that were improperly disposed of over the years. Hopefully, all those tests were done before you bought the home (I know I did).

 The nightmare scenario is what happened in Sterling, Virginia. The short story is that for twenty- or thirty-years homeowners in that community in Loudoun County were drinking water contaminated with TCE and its degradation products. The homes had been built on an old landfill and back in 1988 the Loudoun County Department of Health and the EPA had found traces of TCE, its degradation products and pesticides in three residential wells, but because the contamination was below the regulated maximum contaminant level (MCL) no further investigation was carried out. Apparently, the oddity of finding a solvent in groundwater in a residential community did not immediately prompt further investigation. The water was within safe limits and thus was fine.

However, the water in the neighborhood was not fine. In 2005, 68 more wells (in the community) were tested by the Health Department. “Forty-five wells tested positive for TCE; 17 of these wells contained concentration of TCE above the maximum contaminant level (MCL) of 5 micrograms per liter (mcg/L) while 28 wells contained TCE, but below the MCL.”  The site was declared a CERCLA (Superfund) site in 2008. Between 1988 and 2005 no testing was done on the individual homeowner wells. The water was consumed by the young and old and the homes were bought and sold. If your home had been declared within a Superfund site, it is very likely that the value of the home would be impacted.

Everything that is known about the groundwater in Prince William County is because a study of the groundwater was performed by the U.S. Geological Survey (USGS) in 1991 to study the extent of TCE contamination from the Superfund site in Manassas. They did not test every inch of the county nor look for other contaminants in the groundwater. Their study was designed to find the extent of the TCE contamination plume and where else the contamination might have spread because when you test groundwater and its flow it often surprises.

To be prudent and smart you need to test a well for likely sources of contamination. When I was working as an Environmental Engineer, the biggest challenge was to adequately research the history of a property and then test the soil and groundwater for contamination in the areas most likely to be contaminated. Testing is expensive, so it is virtually impossible to fully test soil and groundwater for everything, and it is very easy to miss the contamination if the study is not planned properly and you do not understand the specific geology. With substances like PFAS, the sensitivity of the tests has increased tremendously as has the knowledge that health can be impacted by extremely low levels of PFOS and PFOA- in the single digit parts per trillion.

When buying a home with a well, you do not have any of this information or resources available to you. Neighbors can be useful or just have no understanding of environmental and groundwater issues and tell you nonsense they’ve heard. If someone asked me about groundwater in my community or my opinion about any specific well, I would tell them, but they would not know my level of expertise. While there are some good historical records available for industrial and commercial properties there is very little information available for residential properties. The department of health often has some useful information about water quality in the county and septic systems but rarely has any water analysis data available. Though, it was a Department of Health employee who originally found the Prince William County TCE contamination.  

Your best option is to do a broad scan of the well water quality. There are screening packages available from U.S. EPA certified laboratories like  National Testing Laboratories that screen water wells for all the primary and secondary contaminants in the Safe Drinking Water Act. The WaterCheck with pesticides package from National Testing Laboratories is a broad stroke test, testing the water for 103 items including Bacteria (Total Coliform and E-Coli), 19 heavy metals and minerals including lead, iron, arsenic and copper (many which are naturally occurring, but can impact health); 6 other inorganic compounds including nitrates and nitrites (can indicate fertilizer residue or animal waste); 5 physical factors including pH, hardness, alkalinity; 4 Trihalomethanes (THMs) and 47 Volatile Organic Chemicals (VOCs) including Benzene, Methyl Tert-Butyl Ether (MTBE) and Trichloroethene (TCE). The pesticide option adds 20 pesticides, herbicides and PCBs.  This testing can be done for a few hundred dollars. I am still waiting to find an affordable and accurate PFAS screen and test, but I’m afraid I will need to wait for the knowledge about potential contaminants to the groundwater and testing to get there.  Prince William county has talked about doing a groundwater study for about a decade now and we’re still not there.   

I’ve done that kind of “full analysis” on my well a few times. These days I test my well annually in the annual water quality clinic sponsored by the Extension office. Groundwater quality is driven by geology, well construction and condition, nearby sources of groundwater contamination, and any water treatment devices and the condition and materials of construction of the household plumbing. Year to year, outside sources of groundwater contamination are not likely to change except with changes in land use. Thus, it is not necessary to test for industrial contaminants every year. To ensure my drinking water remains safe it is important to maintain my well (I replaced the cap six years ago when I replaced the pump), test it regularly and understand your system and geology. I do not have any water treatment in my house; I drink the water just as it is from the ground. If however, you have water treatment equipment in your home you might want to test the water before and after the treatment equipment each year to make sure you have the right equipment for your water and that it continues working properly.