Marin Concrete Plant Agrees to Protect the Bay from Contaminated Runoff

Oct 5, 2015

Shamrock Materials, Inc. recently agreed to implement pollution controls at its San Rafael concrete production plant in order to protect San Francisco Bay from contaminated runoff. Baykeeper brought suit under the Clean Water Act based on the company’s reports of pollution in storm water running off its site.

At Shamrock Materials’ San Rafael facility, the company produces a variety of concrete mixes, and also stores and sells building materials. For the past five years, rainwater running off the site contained pollution at levels higher than EPA water quality standards. The polluted water washed off into storm drains that empty into San Rafael Creek, which flows to San Francisco Bay.

Baykeeper’s legally-binding agreement with Shamrock Materials will protect the Bay from several pollutants that are a threat to wildlife. These include a high level of iron, which can harm or kill fish if they absorb too much. The facility’s runoff was also high in total suspended solids—small particles of dirt and other waste that, in high concentrations, can smother Bay plant and animal life. In addition, the runoff was excessively alkaline, which can also harm or kill aquatic life.

Shamrock Materials is now required to filter runoff water before it leaves the site, and to cover a rebar storage rack to keep rain from coming into contact with iron. The company will also improve its housekeeping procedures. Shamrock Materials will continue to test its storm water runoff for pollutants. Baykeeper will monitor the test results, and if necessary, require further improvements to adequately control pollution from the site.

In addition, to help offset the impacts of its past pollution, Shamrock Materials will provide funds to The Watershed Project for work that benefits San Francisco Bay. 

The agreement with Shamrock Materials is the 29th victory in Baykeeper’s Bay-Safe Industry Campaign. The campaign targets the widespread problem of illegal storm water runoff that flows into San Francisco Bay from Bay Area industrial facilities. In addition to legal action against Shamrock Materials and other facilities found to be significantly polluting the Bay, the campaign includes advocacy and litigation to strengthen regulation of industrial storm water.

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