Bacteria is a common microbial contaminant found in well water. A variety of things can contribute to the presence of bacteria in your well water.
How do I test for bacteria?
Total Coliform bacteria is a test performed to indicate the likelihood of harmful bacteria in the water supply. If there is total coliform present in the water, odds are there are other, more dangerous types of bacteria in the water. It would be difficult, time consuming and expensive to test for every known type of bacteria, virus and parasite, so the Total Coliform test is used as an indicator that some of these are present in the water.
If your test failed for Total Coliform, a second test of the same sample testing for E. Coli was performed to see if that particular bacteria was present.
The only passing result for both total coliform or e. coli is ND (non-detect) or 0.
Even if the E. Coli reading is negative, you should not ignore the Total Coliform reading!
The PA DEP recommends annual testing of your water supply for total coliform bacteria.