Open water well or cistern in a home basement - unsanitary (C) InspectApedia Water Contamination Health Risks
Should We Worry about Well Water Pollution?

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Reasons to check on the sanitation of your drinking water well:

This article describes & expands on US EPA advice on why homeowners need to worry about well water contamination.

Our page top photo shows a cistern-type open well in a home basement.

It is just about impossible for this example-source of drinking water to be consistently sanitary, and the little sediment filter installed will, by itself, not assure that the water is safe to drink.

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Should we Be Concerned About Water Contamination in a Private Well ?

Unidentified chemical drums discovered during a home inspection might indicate an environmental site contamination hazard.This well water contamination article describes types of activities in your area that can create threats to your water supply. It also describes problems to look for and offers maintenance suggestions. Sources for more information and help are also listed.

Our photo (left) illustrates chemical drums we found at a property served by a private well. A bit of research was needed to narrow the range of chemical contaminants for which the property water well should be tested.

Note: InspectApedia editors & contributors have edited an original US EPA article for clarity, content, & depth. Throughout this updated version we also include links to additional detail.

For example where the original article cited the role of distance of a well from sources of pollutants, we include a link to our table of WELL CLEARANCE DISTANCES to provide the actual distances involved.

You should be aware because the Safe Drinking Water Act does not protect private wells. EPA's rules only apply to "public drinking water systems" - government or privately run companies supplying water to 25 people or 15 service connections. While most states regulate private household wells, most have limited rules. Individual well owners have primary responsibility for the safety of the water drawn from their wells.

They do not benefit from the government's health protections for water systems serving many families. These must comply with federal and state regulations for frequent analysis, testing, and reporting of results.

Instead, household well owners should rely on help from local health departments. They may help you with yearly testing for bacteria and nitrates.

They may also oversee the placement and construction of new wells to meet state and local regulations. Most have rules about locating drinking water wells near septic tanks, drain fields, and livestock. But remember, the final responsibility for constructing your well correctly, protecting it from pollution, and maintaining it falls on you, the well owner.

Buying a home with a private water well: take a look at

CHEATING ON WATER TESTS : Testing Water for Real Estate Transactions - make sure your water test is valid

How Much Risk of Water Contamination Can we Expect?

Photograph of  a loose, unsanitary well plumbing system exposed to surface water runoffr  © DJ FriedmanThe risk of having problems depends on how good your well is - how well it was built and located, and how well you maintain it. It also depends on your local environment. That includes the quality of the aquifer from which you draw your water and the human activities going on in your area that can affect your well water.

Our photo at left shows a failed septic tank. Depending on the distance from septic tank or drainfield to the water well, onsite wastewater disposal systems such as this home-made version can be a troublesome source of local well water contamiantion.

Some questions to consider in protecting your drinking water and maintaining your well are:

  • Water well type: the type of water well can make a very large differencein the risk that the well water is contaminatned. For example a water source from a spring subject to surface runoff is difficult to keep sanitary, as are shallow wells and hand dug wells in most areas.
    See WELLS CISTERNS & SPRINGSfor descriptions of the different types of drinking water well\s.
  • Water well clearance distance from sources of pollutants: what distance should my well be from sources of human wastes such as septic systems? How far should a well be from animal feedlots or manure spreading? Details are at WELL CLEARANCE DISTANCES
  • Water well condition, leaks into a well casing due to cracks, splits, or corrosion.
    See WELL CASING LEAK REPAIRS for details.
  • Water well underlying geology: what are the types of soil and underlying rocks? Does water flow easily or collect on the surface? More details are
    at WELL FLOW RATE and

  • Water well depth: how deep must a well be dug to avoid seasonal changes in ground water supply?. More about well depth is
  • Type of activities near the water well: What activities in my area (farming, mining, industry) might affect my well?
  • Well, pump, piping & pargs age: what is the age of my well, its pump, and other parts?
  • Well water distribution system sanitation: leaks into well piping underground can occur durng well pump off cycles and leaks into water piping can also occur in two-line jet pump systems when the pump is operating; also, the water distribution system must be protected from cross connections and backflow problems. Details are

  • Well water treatment system defects: where a water treatment system has been installed in order to protect building occupants from pollutants in the well water, that equipment must be properly installed and maintained or it is unreliable or worse, can itself be a source of contaminants such as bacterial growth. Details about water contaminant treatment equipment & methods are


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WATER WELL CONTAMINATION HAZARDS at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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