While the U.S. Environmental Protection Agency (EPA) regulates public water systems, the responsibility for ensuring the safety and consistent supply of water for the more than 21 million private wells belongs to the well owner. These responsibilities should include knowing the land and well’s history, testing the water quality annually, and having any well system repairs performed by a well driller licensed or certified by the appropriate state agency where the well is located. In Virginia that is the Department of Professional and Occupational Regulation, DPOR.
Groundwater is the largest and most reliable source of freshwater on earth. In the United States 26% of public supplied water is from groundwater in addition to the homes supplied by private wells pump. It has always been assumed that groundwater is protected and safe, but that turns out to be less and less certain. Groundwater and surface water are connected in many ways, not all of them fully understood. Wastewater from agricultural irrigation is used to recharge groundwater and effluent discharge from wastewater treatment plants is intentionally and accidently finding its way into groundwater. In Los Angeles waste water effluent is used to recharge the groundwater, septic systems return their effluent water to groundwater and several studies by the U.S. Geological Survey (USGS) scientists Paul M. Bradley and Larry B. Barber (and others) have shown that waste water contaminants including pharmaceuticals are carried not only downstream into drinking water intakes, but into the shallow groundwater at least 65 feet from the stream.
Scientists are finding that groundwater aquifers are vulnerable to a wide range of man-made and naturally occurring contaminants. Only some of the substances have regulatory or human health screening levels. 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.
The USGS has done lots of groundwater testing over the years. In one study published in 2012 the USGS found that 10 contaminants were widely detected in groundwater and small percentage of the detections were at concentrations greater than human-health recommended levels. Of the ten contaminants, seven were from natural sources and three were man-made. The seven contaminants from natural sources included four geological trace elements (arsenic, manganese, strontium, and boron) and three radionuclides (radon, radium, and gross alpha-particle radioactivity). Radon has been considered several times for regulation in water in the past, but never seems to make the cut.
The three contaminants that exceeded MCLs from mostly man-made sources were nitrate (a nutrient), dieldrin (an insecticide that has been banned by the US EPA, but was previously used for termite control and other applications), and perchloroethene (or PCE, a solvent and degreasing agent used for drycleaning). Each of these contaminants was widely detected in groundwater tested. Nitrate occurs naturally, but most nitrate concentrations greater than 1 milligram per liter (which is one-tenth of the nitrate MCL) originates from man-made sources such as fertilizers, livestock, and human wastewater from septic systems or wastewater treatment plants.
Installation of private wells is regulated by various state
agencies, but these regulations do not require testing the groundwater for a suite of contaminants. State/local agencies that oversee private wells are usually
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. In some regions of the country the
Department of Health tests wells annually.
A drinking water well that is contaminated could significantly impact your health and the value of your property. There are no national regulation and standards for testing a private well; however, I test my drinking water for all the primary and secondary contaminants of concern to the US EPA under the Safe Drinking Water Act every few years and for a smaller list of 14 contaminants annually.
As the providers of our own water supply we need to serve as
our own watch dogs, and ensure our safe water supply, no one else will. Part of
the price of your own water supply is maintaining it and testing it. The local
health departments have local rules and regulations for the installation of
wells and can often help with testing for bacteria and nitrates which are the
typical contaminants from septic systems, drain fields and livestock, but as
the well owner you will need to take the initiative.
The water well test that was performed when you bought your house probably only tested for bacteria and nitrates (unless you live in New Jersey), which is inadequate to be certain that your water is safe to drink. In addition, the EPA recommends that you test your water well every year for total coliform bacteria, nitrates, total dissolved solids, and pH levels at a minimum. If you suspect other contaminants, test for those. Always use a state certified laboratory that conducts drinking water tests.
On March 14, 2023, EPA announced the proposed National Primary Drinking Water Regulation (NPDWR) for six Per- and Polyfluoroalkyl Substances (PFAS) including perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorononanoic acid (PFNA), hexafluoropropylene oxide dimer acid (HFPO-DA, commonly known as GenX Chemicals), perfluorohexane sulfonic acid (PFHxS), and perfluorobutane sulfonic acid (PFBS).
In a recent study by the USGS least one PFAS (of the group tested for) was detected in
20% of private-wells (55/269 tested) and 40% of the public-supply (182/447)
samples collected throughout the US. (McMahon
et al., 2022). Median cumulative PFAS concentrations (estimated given the
detection limits) were comparable between public-supply
(median = 7.1 ng/L) and private–well point-of-use tap water
(median = 8.2 ng/L ). Private well owners are going to have to address
that problem, but first we need to have the public water suppliers figure it
out for us and adapt their solutions to our situations. I’m still waiting for an
easy to use test before I test my well.
According to the Water Systems Council, you need to monitor the condition of the wellhead and inspect the well system annually. In their publications developed in partnership with the EPA they recommend that you routinely inspect your wellhead several times a year. Check the condition of the well covering, casing and well cap to make sure all are in good repair, leaving no cracks or other entry points for potential pollutants. Note any changes in condition. In addition, you should have the well system, including the pump, storage tank, pipes and valves, and water flow, inspected every 5-10 years by a qualified well driller or pump installer. The soil types, groundwater supply and materials of construction and depth of the well will determine the life of the well. Many wells can continue to produce water supply after a pump has failed and only need a new pump to return to service. This is especially true in areas of hard water where the well pump can have a relatively short life. If you notice a change in your water pressure, it may be time to have your system inspected. Do not ignore any changes in your water supply.
A drop in water pressure can originate in the pressure tank, the pressure switch, the pump or the well and water supply. A loss of charge in the pressure tank can be caused by a leak in the bladder. Pressure to the tank is controlled by an electric switch that turns the pump on when pressure is low and off when the proper tank pressure is reached. A pressure switch can fail. In the well, a diminished water supply can be caused by drop in water level in the well due to drought or over pumping of the aquifer, iron bacteria or other buildup in the pipe, or the well could be failing or a drop in pressure could be caused by a failing or damaged pump. Of course, a drop in water pressure could just be caused by increased demand, if your pump is undersized for the number of plumbing fixtures in the house then using more than one bathroom at a time or doing laundry while hosing down the patio will cause a noticeable drop in water pressure.
These are just examples of the kind of understanding you need to have when you operate your own water system. When you own a well, you are in charge, you are responsible, you need to be informed.