Manganese Advisory
The established Secondary Maximum Contaminant Level (SMCL) for Manganese is 50 ppb (parts per billion). "Secondary drinking water standards" means standards that specify maximum contaminant levels that, in the judgment of the California State Department of Health, are necessary to protect the public welfare. Secondary drinking water standards may apply to any contaminant in drinking water that may adversely affect the odor or appearance of the water. Manganese is a common metal found in the environment, is naturally occurring in groundwater, and high concentrations may turn your water brown or leave black colored deposits on plumbing fixtures.
Some of the City’s wells have naturally occurring Manganese and as these wells deliver water to the distribution system, mineral deposits will build up over time on our main lines and these deposits may become dislodged and enter into the consumer’s service line. This may cause discolored water to enter into the home and may leave stains on plumbing fixtures. Occasionally, some of the wells exceed the SMCL for Manganese. When this occurs, the well is taken off-line and is used for emergency purposes only.
The City has implemented a flushing program to control this build-up of minerals on the main lines. These lines are flushed annually to scour the walls and remove the mineral deposits. However, the deposits can randomly become dislodged and end up in the consumer’s home.
The City has drilled two production wells that have Manganese levels exceeding the SMCL. The City is in the process of constructing a Manganese Treatment System at both sites to remove the Manganese before it enters the distribution system. Well 32 is scheduled to go on-line in summer of 2011 and Well 34 is scheduled to go on-line late next year.
If you experience any problems with your water supply or have any questions, please contact the Public Works Office at 530.757.5686 during regular business hours or contact the non-emergency police number at 530.757.5400 after hours for assistance.
