Microbiological Contaminants

Why test for microbiological contaminants?

Microbiological testing of water helps protect the public from diseases. Chlorine is added to drinking water as a disinfectant to destroy or inactivate bacteria, viruses, and protozoa.

City of Pendleton drinking water is routinely sampled for both total coliform Bacteria and E. Coli Bacteria. Total coliform bacteria are naturally present in the environment, and their presence of E. Coli bacteria indicates that water may be contaminated with human or animal wastes.

Most recent sampling

There were 240 routine microbiological samples taken throughout the distribution system in 2023. One incident of E. Coli bacteria was detected and quickly resolved in 2023.