Local Power Plants Harm Bay Wildlife

Apr 1, 2009
Sejal Choksi
by Sejal Choksi

In the wake of increasingly alarming climate change data and a growing movement to reduce our nation’s dependence on fossil fuels, energy issues have risen to the top of the national environmental agenda. The Obama administration has pledged to craft a sustainable national energy policy that promotes renewable sources of energy and minimizes the harmful environmental impacts of our energy consumption on air quality and global climate change. What many Bay Area residents don’t realize is that here in California, our energy production harms some of our state’s most precious resources: our coastal waters, bays, estuaries, fisheries and marine wildlife. This is because about twenty percent of California’s energy is produced by coastal and bayside power plants that use an antiquated process called once-through cooling. Concerned residents around the country are calling for an end to the use of this harmful and inefficient technology, and San Francisco Baykeeper is working to phase out the use of once-through cooling at power plants here in the Bay Area.

Once-through cooling is a process that pulls in cold sea and bay water to cool power plant turbines and then releases the heated water back into the environment. Every day, 16 billion gallons of marine waters are sucked into California’s power plants, killing nearly everything that passes through the plants’ machinery. Larvae and small fish get pulled into the plant and die in the turbines (“impingement”), while larger fish and marine mammals get trapped on the intake screens by the force of the rushing water (“entrainment”). 79 billion fish and other marine animals are killed every year in California waters by once-through cooling.

Widely regarded as an outdated technology, once-though cooling has been used at Bay Area power plants for decades, to the detriment of our local environment. The Mirant Delta corporation operates three once-through cooling plants on the Bay, in San Francisco, Pittsburgh and Antioch. Although the three Bay plants are “peaker plants” – meaning they provide energy only during the periods of highest consumption – the plants’ cooling systems operate year-round and consistently impact San Francisco Bay. The intake process, which causes the impingement and entrainment of marine animals, can kill organisms from all levels of the food chain and disrupt the normal processes of the Bay’s ecosystem. Additionally, the plants release heated water that can reach temperatures as high as 100 degrees. The Bay’s normal temperature rarely goes above 70 degrees, so a sudden influx of hot water can disrupt the Bay’s delicate ecosystem and the animals living in it. The fishing industry feels the impacts too, as once-through cooling depletes fishery stocks and threatens the survival of California's salmon and Pacific herring, the Bay's last commercial fishery.

Baykeeper is part of a coalition of environmental and fishing groups that is aggressively fighting the continued use of once-through cooling. We’re supporting a bill in the California Legislature that would force inefficient coastal power plants – including all three of the plants along the San Francisco Bay shoreline – to switch to less environmentally damaging cooling systems by the year 2015. The bill, authored by Senator Ellen Corbett (D-San Leandro), would also require the State Water Board to create a timeline that completely phases out the use of once-through cooling at California power plants. This bill is critical to protecting California’s marine ecosystems, but there is opposition from the energy industry, which has been reluctant to take responsibility for the environmental costs of their operations.

The use of once-through cooling has sparked a legal battle that has gone all the way to the United States Supreme Court. Baykeeper’s ally Hudson Riverkeeper sued the U.S. Environmental Protection Agency when the agency proposed that economic concerns of the energy industry outweigh the protection of marine life when considering alternatives to once-through cooling. The Supreme Court heard oral arguments for the case in December 2008, and a decision is expected soon. The Court’s ruling could help steer the Obama administration as it develops a national policy that moves our energy production away from the harmful use of once-through cooling and toward healthier and more sustainable sources of energy.

In the meantime, San Francisco Baykeeper and our partners and allies will do all we can to tell California’s policy-makers how important it is to phase out once-through cooling. To join Baykeeper and learn more about how to voice your support for ending once-through cooling, visit www.baykeeper.org.

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