City switches treatment of lake water

Napa Valley Register Online | LocalNews: “City switches treatment of lake water”

By JULISSA McKINNON, Register Staff Writer
Monday, August 14, 2006 1:14 AM PDT

After local environmentalists sounded the alarm on the city’s use of copper sulfate to kill algae in Napa’s main reservoir, water officials are switching to an alternative herbicide.

Members of Earth Defense for the Environment Now objected last spring to the city’s application of copper sulfate to Lake Hennessey, citing the heavy metal’s well-documented effects of decimating fish, frogs and other aquatic life. Like other heavy-impact pollutants, copper accumulates in higher concentrations as it moves up the food chain.

The group also protested the fact that the water division had not conducted a review of copper sulfate’s environmental effects after the city asserted that the impact of a decade’s worth of copper sulfate use was negligible. After EDEN contested that claim, the city stopped using copper sulfate, and has yet to decide whether it will resume, according to Phil Brun, general manager of the city’s water division.

In the meantime, the city plans to try a new algaecide — PAK-27 — to eradicate the lake’s green goo.

Click on link to view entire article. Thanks to David Rosenthall for the submission