Untreated water was mixed with treated water in an East Bay reservoir on March 3 and then went on to the regional water system, which delivers to an estimated 3,500 customers of the Menlo Park Municipal Water District, according to the city, which issued a written statement about the incident on March 20.
The untreated water "passed through the system that same day and was gone within a couple of hours," Public Works Director Jesse Quirion said.
A valve had been left open on March 3 by San Francisco Public Utilities workers at the San Antonio Reservoir, according to the announcement. Blending with the treated water provided some disinfection and customers have no need to take any actions such as boiling water before using it.
The SFPUC has transferred the remaining affected water to a different reservoir for further treatment, the city said.
Call 330-6750 or email firstname.lastname@example.org for more information. The SFPUC is available at (866) 973-1476.