Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially harmful bacteria may be present. Coliform bacteria should not be present in drinking water. If the sample is positive for total coliform, the lab will determine whether E. coli is also present. E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes.
If coliform bacteria is found, boil the water for at least one minute at a rolling boil (longer if you live at high altitudes) before drinking.
Treatment of the well, followed by retesting, is recommended. Use the following link for instructions on how to disinfect a well.
Note: Most in-home filters will not remove E.coli from water.