Michigan’s well construction code requires that after construction or repair of a well, the well must be disinfected, and then flushed to waste. The person constructing or repairing the well is required to disinfect the well.  After all chlorine is removed from the system, the water well is required to be tested for coliform bacteria and partial chemistry. Well owners are responsible for the collection of all required water samples.

Water Sampling of Residential Wells

• DHD4’s well construction code requires a coliform bacteria sample and partial chemistry sample be taken for all new, repaired, and reconditioned wells.

• The coliform bacteria test must show the absence of coliform bacteria.

• District Health Department No. 4 also requires that a nitrate water sample be collected from all newly constructed wells, in addition to the coliform bacteria sample. The partial chemistry sample will test for: chloride, fluoride, sodium, sulfate, hardness as CaCO3, iron, nitrate, and nitrite.

• Water sample bottles can be obtained, from the local health department office. They are provided with a shipping container with a mailing address.

• The sample must be taken or mailed to a state certified laboratory.

• Seasonal wells that are depressurized should be disinfected and sampled prior to consuming the water at the start of the season.

• Annual coliform bacteria sampling is recommended.

Other water samples may be required by District Health Department No. 4, as part of a well permit requirement:  for example, if a water well is near a source of contamination.

Please contact your local health department if you wish to discuss the results of your water samples.