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East County News Service

April 9, 2015 (San Diego’s East County) – The San Diego County Water Authority is proposing to apply copper-based algaecides to control algae blooms at five reservoirs that supply drinking water, including Lake Jennings(Helix Water District), Sweetwater Reservoir (Sweetwater Authority), Lake Poway (City of Poway), Olivenhain Reservoir (County Water Authority) and San Dieguito Resrvoir (Santa Fe Irrigation District.)

Public comments are accepted through April 13th at 5 p.m. at; include “Algaecide MND comments in the email subject line, or email comments to AECOM, Attn: Alex Hardy, 401 West A St., Suite 1200, San Diego CA 92101.

The Water Authority is the lead agency under the California Enviornmental Quality Act (CEQA) and seeks to adopt a mitigated negative declaration (MND) for application of the algaecides.  The treatment may require temporary exceeding of levels allowed for copper in drinking water.

The draft MND can be viewed at

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Water Treatment

Algae blooms cause taste and odor problems in your drinking water and are difficult to remove in the water treatment process. Copper sulphate has been used for many years to control algae growth as the water warms in the springtime. It's spread around the lake but not close to the intake to the treatment plant.
If it wasn't applied your tap water would smell bad,. It's a powerful oxidizer but doesn't get to your home.