My laboratory report says bacteria is present in my sample. Now what do I do?

If only Total Coliform is present, MDHSS recommends collecting a second sample to ensure the test is a true representation of your water quality before taking further action. It is possible to unknowingly introduce bacteria to the sample if the collection instructions are not followed closely. If the second Total Coliform sample is present, follow the MDHSS well disinfection instructions. Disinfection instructions can be found at

health.mo.gov/private-drinking-water under the Bacteriological Testing tab.

If E.coli is present, MDHSS recommends disinfecting your well. Disinfection instructions can be found at health.mo.gov/private-drinking-water under the Bacteriological Testing tab. MDHSS also recommends an additional bacteria test to ensure that the disinfection was successful.

Discontinue use of the water supply for drinking and culinary purposes including any ice made with the untreated water until your well is properly disinfected. Perform immediate disinfection for all water used for drinking or culinary purposes by boiling vigorously for one (1) full minute before use; or add two(2) drops (double the amount for cloudy or colored water) of regular household chlorine bleach (5.25 percent or higher chlorine) to each quart of water used. Mix thoroughly and allow to stand for 30 minutes before use.

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