Marin tap water full of algae

Got algae? Marin does.

The Marin Municipal Water District has received a host of complaints recently that local tap water sourced from the Nicasio Reservoir is tasting a little suspect.

MMWD said there is good reason for this. In the warm summer months, an algae known as oscillatoria blooms and decays in Nicasio reservoir and Stafford Lake. Although a treatment plant processes the water, an unpleasant taste and smell remain for Marin folks to savor.

To help combat the problem, copper sulfate has been added to local water sources to reduce growth of the algae. Officials say the taste should be gone in a few days, and the water is still — and always has been — safe to drink.

The Marin Municipal Water District serves 190,000 customers. When paired with the North Marin Water District, a quarter of a million people — from San Rafael to Sausalito and into West Marin — may have been affected by the algae decay.

Chris DeGabriele, the water district’s general manager, told the Marin IJ:

“It has been a challenge this year but it seems to be getting better. Lakes are living bodies; each year, each season and even each day is different.”

DeGabriele hypothesizes the increase in algae this year can be traced to late springs rains. The reservoir and lake were more stagnant than normal as the weather heated up, sending the oscillatoria into overdrive. As daytime temperatures cool off it will eventually disappear.