MWRA announced today that it has been monitoring the customary early-Spring bloom of the harmless Asterionella* algae strain in the waters of the Wachusett Reservoir. The Wachusett is one of the reservoirs that supply drinking water to 2.2 million people in metropolitan Boston.

The specific strain of algae naturally appears in the reservoir around the same time each year, and does not adversely affect the safety, taste or odor of the drinking water. The algae can, however, accelerate the clogging of household water filter systems and filter jugs.

"Residents who use household drinking water filters should monitor their filters," said MWRA Quality Assurance Program Manager, Dr. Betsy Reilley-Matthews. "Filter systems may have to be changed more frequently than usual over the next few weeks."

MWRA monitors numerous water quality parameters in the reservoir throughout the year, including algae. The natural cycle of the Asterionella bloom usually lasts for a few weeks each spring.

MWRA believes that providing testing information on MWRA drinking water is important to its customers. Testing results are made available in monthly reports mailed to public officials and others.

For further information call MWRA Waterworks at (617) 242-5323.

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