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.