Private Well Maintenance

The Center for Disease Control recommends wells are checked for mechanical issues every spring and tested annually for total coliform bacteria, nitrates, dissolved solids, and pH levels to ensure well integrity.

If other forms of contamination are of concern, other tests may be performed as well.

Homeowners should be aware of potential issues that may arise throughout the course of the year such as mechanical problems, contamination issues, and cleanliness around the well.

Physically, the well casing, well cap, and electrical conduit should all be in good condition. Chemicals, such as paint, fertilizer, pesticides, and potential bacterial contaminants, such as livestock yards or dog kennels, should be a proper distance away from the well.


Erosion control practices:
intentional efforts to reduce soil erosion, or displacement, to decrease the likelihood of pollutants becoming introduced into the environment in harmful quantities. Practices may include increased vegetation, wildlife restoration or installation of synthetic barriers.

Specific, mandated distances are as follows:

  • 50 feet from any septic tank
  • 50 feet from any livestock yards, silos, or septic leach fields
  • 100 feet from petroleum tanks or liquid-tight manure storage and handling sites
  • 250 feet from manure stacks or related open collections of organic waste.

Household and lawn care chemicals should also be kept an appropriate distance away from the well and one should actively reduce surface runoff through erosion control practices.

To prevent contamination of the groundwater aquifer, underground tanks that contain oil, diesel, or gas should be checked regularly for leaks. Additionally, if the wellhead lies in an area prone to flooding, consider hiring a licensed professional to raise the wellhead above the flood level to prevent serious contamination.

If you experience a change in your water’s taste or odor, if your water becomes cloudy or if the well cap has been removed, it is also recommended that you schedule an inspection with a local water quality professional.

If your well has tested positive for total coliform, fecal coliform, or any other test indicating a potential health concern, contact your local health department. If your well has tested positive for anaerobic bacteria, it should be cleaned and disinfected by a licensed water systems professional.

In general, it is good practice to keep up-to-date records of well installation, repairs, and testing, and to keep the area around the well clear of potential contaminants.




The siting or location of your well has a huge effect on its safety and effectiveness.

When placing a new well, minimum distances between the well and potential sources of contaminants, such as septic tanks, livestock yards, and petroleum tanks, should be followed.

Groundwater can become contaminated by microorganisms through fecal contamination, naturally-occurring chemicals such as arsenic and radon, and synthetic and organic chemicals from fertilizers and pesticides, and other emerging contamination concerns. One of the most common sources of well contamination is failed septic tanks.

If you are planning on constructing a new well, a state-licensed contractor, local health department, or local water system professional can provide further information about constructing a well in your area. These professionals may also be able to provide information on the depth of other wells within your area.


Currently, most groundwater sources are relatively clean of harmful contaminants and can be safely consumed with little to no further treatment. However, the high quality of Michigan’s groundwater is at risk from urbanization and common agricultural and industrial practices.

Common sources of groundwater contamination include seepage from landfills, failed septic tanks, underground storage tanks, fertilizers and pesticides, and runoff from urban areas. Wells drilled deeper within the surface are more resistant to contamination, however, pollution can still occur.

Wells are susceptible to both chemical and biological contamination. According to the Center for Disease Control (CDC), the most common outbreak-causing biological contaminants in wells include the Hepatitis A virus, Giardia, Escherichia coli (E. coli), Campylobacter, Shigella, Cryptosporidium, and Salmonella. Chemical contaminants, such as arsenic, gasoline, nitrate, phenols, and selenium, can also be present but are less likely to cause outbreaks.

There are several water quality indicators (WQI) and contaminants that homeowners with private wells should test for. A WQI test for the presence or absence of specific microorganisms that could indicate the contamination by disease-causing organisms, called pathogens. Usually, the organisms that the test targets are not the organisms that cause the disease, but it does indicate the presence of fecal contamination.

Common WQIs include Total Coliform, Fecal Coliform, and pH levels. Other contaminants that are for a water system should be tested for on a regular basis include Nitrate and Volatile Organic Compounds (VOCs) which can be harmful to human health at high levels.


While in general well water is relatively high quality, homeowners with a well may choose to treat their well water to remove specific contaminants, as an extra layer of protection against pathogens, or for increased cosmetic quality (taste, smell, coloring).

Two types of treatment systems are commonly used for household well water: point-of-use (POU) and point-of-entry (POE).

Point-of-use systems are typically installed near where water is used, such as a tap, and only treats the water flowing out of that faucet.

Point-of-entry systems are installed after the water meter and treat most of the water entering the household by filtering out ‘hard water’ minerals with softeners, and reducing pathogens.

Since a single treatment system cannot remove all contaminants, it is recommended that a household’s water is tested regularly, and a water treatment system is chosen based on specific contaminants of concern. When purchasing a treatment system, it is also important to consider units that have been certified by an independent testing agency such as the National Sanitation Foundation (NSF) or the Water Quality Association (WQA) to ensure treatment efficiency.