Olalla Water System: Notice of chlorine added to tank

On Tuesday, May 26, 2026, Washington Water Service will be adding chlorine to the storage tank serving Olalla Water System. This is being done as a precautionary measure, after coliform bacteria was found in a sample collected from the water system. Although this incident was not an emergency, customers of the water system have a right to know what happened and what Washington Water Service did or is doing to correct the situation.

Coliforms are bacteria which are naturally present in the environment, harmless to the general population and are used as an indicator that other potentially harmful bacteria may be present. The presence of coliform bacteria is a warning of potential problems because pathogens (organisms which can cause disease) may also enter the system via the same route as the coliform bacteria. The presence of coliforms usually means that soil or vegetation has entered the system. Any sample that shows the presence of coliforms is further tested to see if other bacteria of greater concern, such as fecal coliform or E. coli are present. As none of these bacteria were found, your water was – and continues to be – safe to drink. You do NOT need to boil your water.  People with severely compromised immune systems, infants and some elderly may be at an increased risk and may want to contact their health care provider for additional guidance.

As stated above, chlorine will be added to the storage tank to disinfect and rid the distribution mains of the coliform bacteria. Additional samples will be collected once chlorine is absent to confirm that the coliforms have been eliminated from the water system.

We apologize for the inconvenience.  Protecting your health and safety is our highest priority. If you have any questions, please do not hesitate to call our Customer Service Center. We can be reached toll-free at (877) 408-4060 or by email at [email protected].