Annual testing of private drinking water wells is not required or tracked in Virginia. The Virginia Department of Health recommends that private water supplies be analyzed for total coliform at least once a year, but does not require it. Routine testing of private wells takes place during the underwriting of a mortgage, but at no other time. Undoubtedly, when you purchased your home, the well was tested, but that may have been the last time you bothered to test your well. Owners of private drinking water wells are responsible for their own water quality and should monitor it. This spring I used the WaterCheck with Pesticides to test my water quality. This is a test kit you can either buy and take the sample yourself and ship it off to the laboratory in Michigan or you can have a local laboratory do the sampling to ensure that the local laboratory does a same day analysis for Bacteria (presence/absence for coliform and E. coli) and nitrates. The kits are made by National Testing Labs and can be purchased directly from them or from a variety of distributors.
Over 15 million people in the United States receive their water from private ground water wells. EPA regulations that protect public drinking water systems do not apply to privately owned wells. As a result, owners of private wells are responsible for ensuring that their water is safe from contaminants. According to the U.S. Environmental Protection Agency, septic systems are a major source of contamination of an underground water supply (well or spring). Inappropriate siting of drain fields, and poor design, construction, and maintenance of septic systems, coupled with improper well construction, can lead to contamination of household water. There has been little data collected on frequency and type of private well contamination, but clearly fecal bacteria present in water from the well could indicate contamination from septic or other animal waste. My home is located in an area of horse and cattle farms in an area with very little overburden to protect the aquifer. I keep and eye on my groundwater quality.
There are also vectors of contamination that may result in the introduction of contaminants into a private water supply that do not impact the groundwater supply. Coliform bacteria are commonly found in soil, on vegetation, and in surface water. They also live in the intestines of warm-blooded animals and humans. Some coliform bacteria strains can survive in soil and water for long periods of time. Bacteria washed into the ground by rainfall or snowmelt are usually filtered out as water seeps through the soil, so properly constructed water wells do not typically harbor Coliform bacteria. A well pipe that is improperly grouted or where the grouting has been damaged over time may serve as a vector of contamination of surface runoff.
The test for the presence of coliform bacteria is relatively inexpensive and easy to perform. The standard test is called total coliform and it serves as a proxy for other types of contamination. Water samples that contain any coliform bacteria are generally reported as "total coliform positive" and should be analyzed for fecal coliform or E.coli which test specifically for the bacteria found in the digestive system of humans and animals. These fecal bacteria originate only in human and animal waste. It is unacceptable for fecal bacteria to be present in any concentration in a water supply. Bacteria in water cannot be seen, tasted, or smelled and many health-related symptoms are not immediate. Therefore, the only way to reliably determine if water is contaminated is by a laboratory test. Testing a water supply for a specific disease-causing organism can be expensive. Instead, water supplies are usually tested for the presence of coliform bacteria and only if the water tests positive for coliform is further analysis done.
The Center for Disease Control recommends at a minimum, you should check your well every spring to make sure there are no mechanical problems; test it once each year for total coliform bacteria, nitrates, total dissolved solids, and pH levels. If there is reason to suspect other contaminants, you should test for those as well remembering that analysis is expensive. The Virginia department of Health recommends regular testing of your drinking water well when any of the following conditions apply:
there is an infant in the home;
a new well is constructed;
flooding occurs near the well or spring;
any person or animal becomes sick from a suspected waterborne disease; or
The water supply system on a well or spring has been disassembled for repairs to components such as the well itself, pump, pressure tank, treatment devices or pipe lines.
The question is should the Virginia Department of Health require the testing of private wells annually? If the data from well testing were collected and plotted, areas where the groundwater had be impacted from septic leakage might be identified in a more timely fashion and the conditions of geologically sensitive groundwater could be monitored. The public and private drinking water wells of the state could serve as a proxy to track the health of one of our most valuable resources. Instead of requiring the annual testing of private wells the Department of Health should continue to encourage and recommend the annual testing and collect the plot the data obtained in that way. Data collected over a period of time can be very revealing.
The groundwater basin where my home is located consists of highly fractured rock, and overlain by a thin cover of overburden. The lack of overburden limits natural protection to the aquifer. The sedimentary rocks are highly productive aquifers, but also subject to fractures that allow contaminants to move swiftly and easily through the system and easily reach depth in the groundwater aquifer. There is no natural attenuation in a fractured system. Any malfunctioning septic system, improper disposal, or spill on any property has the potential to impact the drinking water well of other residents to the south, southeast or east. Thus, as a group our neighborhood has decided to test all the private wells every spring and track the data to monitor our aquifer.