Friday, January 1, 2010

West Side Boil Alert Update

By now I hope you’ve heard the E. coli found in water samples from Reservoir 3 over the Thanksgiving holiday was non-infectious; meaning it was harmless to human beings, and just one of the many types of innocuous bacteria we encounter in our normal environment every day. (Water Bureau press release available here: )

In reading data at the State’s Drinking Water Program website ( ), one can see that E.coli detects happen in all parts of our water system, not just in the open reservoirs. In fact, Conduit #4 (a buried pipeline) has had repeated E.coli detects this year -- boil alerts are not issued with these E.coli detects because, reportedly, regulation does not require them to be issued (case report for Conduit #4: ).

I find any suggestion that the City should spend $400 million (cost to bury reservoirs, $800 million with debt service) an inappropriate reaction to a harmless bacteria. Covering your drinking water does not prevent debris from getting into it; as long as there is an inlet and an outlet there is an entry point for contaminants. Water managers contend with environmental contaminants, whether they are running open or closed systems.

Read this EPA white paper to learn more about debris in water storage facilities: . Interestingly, all of the cases cited in this document where illness and death occur as a result of contamination were from incidents in covered storage facilities. The authors speculate that debris should be an even bigger problem in open reservoirs, but I cannot find an EPA citation supporting that speculation.