Frequently Asked Questions

Is this test the same as a public health or professional bacteria test?

No. In-home screening kits for total coliforms will not be as accurate as laboratory testing. However, total coliform screening is very commonly used by public health and third party certified laboratories as coliforms are easily and inexpensively detected. In some instances, testing may also include fecal coliforms or E. coli. These are more specific indicators of recent fecal contamination.

What’s the difference between total coliforms, fecal coliforms, and E. coli?

Total coliforms are a broad group of bacteria that are always found in fecal matter but can also be found in soil and vegetation. Fecal coliforms are a subgroup that are associated only with human and animal waste. E.coli is a specific strain that is only found in fecal matter, making it the best indicator of fecal contamination.

My water sample was coliform positive. Can I just “shock” my well with bleach?

There are many reasons coliform bacteria could be in your sample. If, for example, surface water is getting into your well or the aquifer (source of water for your well) is itself contaminated, shocking alone will not be an effective solution.

How does surface water get into a well?

Surface water intrusion can happen in a number of ways. For instance, surface water can get into your well if the well cap is missing or damaged. Or, seepage may occur through cracks or holes in the well casing or along the outside of the well casing for wells constructed at a time when sealing with grout was not required. Another frequent cause is well flooding from heavy rainfall, hurricanes, or significant snowmelt.

Will an in-home screening test tell me if my water is safe to drink?

No. An in-home screening test will give you a quick indication of the risk of microbial contamination in your well water. Testing your water through your public health agency or other certified lab is always best. In addition your public health agency can help you to understand what other water testing is recommended for your local area as other natural and man-made contaminants can impact your health.