Cristalina: Notice of Chlorine Being Added to Water System

The Cristalina Water System, ID#03014H, located in King County and owned by Washington Water Service, routinely monitors for the presence of total coliform bacteria.  On October 23, 2025, we learned from the laboratory that this type of bacteria was detected in the monthly bacteriological sample collected on October 22, 2025.  Although this incident is not an emergency, as our customer, you have a right to know what happened and what is being done 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 samples that are positive for the presence of coliforms are further tested to see if other bacteria of greater concern, such as E. coli are present.  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.

What has been done, or is being done, to correct the problem?

• Friday, October 24 – Upon learning of the unsatisfactory result, follow-up samples were collected throughout the system, including from the well and the original sample site. This is to confirm the presence of coliform bacteria and to determine its source/origin so it can be eliminated.
• Monday, October 27 – The results of the follow up samples confirmed the presence of total coliform bacteria in the system, originating in the storage tank.  All samples were absent of E. coli bacteria.
• Wednesday, November 12 – Chlorination equipment will be installed and placed in service to continuously disinfect and rid the storage tank and distribution mains of the coliform bacteria.  Your water is safe to drink. You do not need to boil your water.

 

This action is the first step in further improvements to the Cristalina Water System.  We appreciate your understanding as we work to correct this water quality situation.

 

If you have any questions, please contact our Customer Service Department toll-free at (877) 408-4060 or by email at [email protected].