Testing Your Well

I test my well water every year, though there is no requirement that I do that. I am one of the 1.6 million Virginians who get their drinking water from a well, cistern or spring.  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. Every year I test my well water to make sure it is safe to drink. I do not test for everything and only periodically perform broad tests looking for changes in the groundwater quality. 

Private wells draw groundwater to a large extent from the area surrounding the well. Depending on the depth of the well and the local geology groundwater drawn into a private domestic drinking water well is often young-it could be weeks, months or several years old. Even though the ground is an excellent mechanism for filtering out particulate matter, such as leaves, soil, and bugs, dissolved chemicals and gases can still occur in large enough concentrations in groundwater to cause problems. Groundwater can get contaminated from industrial, domestic, and agricultural chemicals from the surface; including  pesticides and herbicides that many homeowners apply to their lawns, improperly disposed of chemicals; animal wastes; failing septic systems; wastes disposed underground; and naturally-occurring substances can all contaminate drinking water and make it unsuitable for drinking or make the water unpleasant to drink. Groundwater is dynamic and can change over time. Regular monitoring of your water quality is important and entirely up to you.

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 a bacterial testing after completion. Then you are on your own to do what you deem best. When a house is purchased, 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.

When we bought our home, I tested the well for all the primary and secondary contaminants in the Safe Drinking Water Act as well as a suite of metals and pesticides using a certified laboratory. I wanted a comprehensive baseline, and I used the safe drinking water act as my screening mechanism. I have performed that testing a handful of times over the past two decades using a testing package, the WaterCheck Deluxe plus pesticides test kit from National Testing Laboratories which is an EPA certified laboratory, to save money. Buying a package reduces the cost though the drawback is these packages are performed at a lower sensitivity level, and this was the most economical test I found. (I paid around 5 or 6 times what the WaterCheck with pesticides costs today to have my well tested 20 years ago.)

Still, I did not test for everything, nobody could afford to (I think there are 80,000 or more known chemicals). At the time I did not test for PFAS it was not part of the Safe Drinking Water Act and  the testing methods were not as sensitive as they are today. Truthfully,  it just was not on my radar, though I had been an R&D engineer at DuPont back in the day.

Currently, there are three U.S. EPA testing methodologies for testing drinking water for PFAS- USEPA Methods 537, 537.1, or 533. These methods test for multiple PFAS compounds, including the PFAS compounds that are part of the current EPA Drinking Water Standards.  The real problem is that Point of Use (POU) and Point of Entry (POE) treatment devices are not specifically designed to meet the Federal drinking water standards for PFAS. Current certification standards for PFAS filters NSF/ANSI 53 or NSF/ANSI 58 standards) do not yet indicate that a filter will remove PFAS down to the levels EPA has now set for a drinking water standard. EPA is working with standard-setting bodies to update their filter certifications to match EPA’s new requirements. Stay tuned.

Since I do not live in an area with a high probability of PFAS contamination, I am going to wait until the Occoquan Watershed Laboratory has finished their PFAS investigation of the   Occoquan watershed to determine where the PFAS in the reservoir is coming from. Sampling has so far confirmed Industrial wastewater discharges to UOSA from the Micron Semiconductor plant and from Freestate Farms. Also confirmed as a source of PFAS by sampling is the Federal/Military in the Vint Hill area and Vint Hill Farms. There are also several potential sources that need to be further investigated: the non-Micron reclaimed water from UOSA, accidental releases from Manassas airport, Dulles Airport, the legacy CERCLA sites – IBM in Manassas and Atlantic Research in Gainesville currently being redeveloped into data centers. PFAS in biosolids that may have been land applied under a permit in the watershed. PFAS have been widely used in consumer products, it is possible that some septic systems and landfills may also be a source of PFAS in groundwater. I will leave further discussion of this point to a later date.

If your home has a drinking water well that is contaminated, it could impact your health and the health of your family, and the value of the property. Still, according to the Virginia Household Water Quality Program, the most common contaminants in a private well are coliform bacteria and sodium.  Total coliform bacteria while always present in manure and sewage, 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 possibly from the aquifer. Absence of coliform bacteria only means that water is not contaminated by septic and surface runoff, but the water might contain contaminants from other sources. Excessive sodium in Virginia generally comes from the overuse of water softeners and not from salt water infiltration.

There is a whole lot beyond being clear and tasting good that makes water safe and satisfactory. The issue of whether water is safe to drink is separate from whether the water is free of unpleasant contaminants like iron, manganese, chloride, and low levels of hydrogen sulfide or the groundwater has been contaminated. Throughout Virginia the Extension Office holds water clinics as part of the Virginia Household Water Quality Program.  For a reasonable price they analyzed water samples for 14 chemical and bacteriological contaminants at the laboratory at Virginia Tech.  Samples are analyzed for: iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria. These are the most common problems. I use the program to take a quick look at my water to see if anything has changed.

Due to its protected location underground, most groundwater is naturally 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 and 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 performed. 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 but felt that they were able to find the extent of the TCE contamination plume. To be prudent and smart you need to test a well for likely and some unlikely sources of contamination. Often the biggest challenge in finding contamination is knowing what to look for and where to test. 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 geology.

When buying a single-family home, you do not have any of this information or resources available to you. 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 before you buy the house and certainly at least once a decade when you own it. 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. This testing can be done for a few hundred dollars.  You might want to add nuisance problems like reducing bacteria.  

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, 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 you have water treatment equipment in your home, you might want to get 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.