SAN FRANCISCO | San Francisco wears its environmental consciousness like a green badge of honor.
Residents separate and recycle their food scraps. Streets close to cars so people can walk and bike them. A city department even gives away “high-quality, nutrient-rich, organic biosolids compost” to all takers.
But a public interest and environmental advocacy group says the city’s free compost, used by community, backyard and school gardens, is processed sewage sludge — the product of anything flushed, poured or dumped into the wastewater system.
The sludge, the group says, includes potentially thousands of industrial, pharmaceutical and chemical toxins and carcinogens.
“This sludge belongs in a hazardous waste dump,” said Ronnie Cummins, the Organic Consumers Association’s national director, before he poured some of the compost on carefully laid out plastic sheeting at the steps of San Francisco City Hall on Thursday.
The protest, he said, was the launch of a campaign the organic foods movement is planning to wage against the use of biosolids compost.
Several cities in California have biosolid compost giveaways, including Los Angeles, San Diego, San Juan Capistrano, Santa Rosa, Fortuna, Carlsbad and Calabasas, according to the Organic Consumers Association.
Sewage or biosolids compost is also packaged and sold in major house and garden centers across the country.
Fertilizer made from biosolids is used on millions of acres of land all over the United States to grow plants, according to a report by the U.S. Geological Survey. That fertilizer is not treated and heated to the point where it becomes compost and is not used for human food crops, though it is used for animal food crops.
San Francisco’s biosolids compost has become the focal point for the issue precisely because it is so environmentally aware, say organic groups. “San Francisco as the greenest large city in the country should be the first to stop this,” Mr. Cummins said.
But the San Francisco Public Utilities Commission (PUC), which manages the city’s sewage treatment, says that the 1 percent of the city’s 80,000 tons of sewage that is converted into compost each year is treated and tested to the point of sterility.
Federally mandated testing shows that the compost has far lower levels of nine pollutants than the Environmental Protection Agency deems acceptable, a PUC spokesman said. “We’re in the business of protecting public health and the environment,” said Tyrone Jue. “That’s our mandate and our mission statement. That’s what we do. If for even a minute we thought one of our activities was going against that mandate, we would absolutely stop doing it.”
But the problem, say groups like the Organic Consumers Association and the Center for Food Safety, is that the EPA only requires testing for nine metals, when there are potentially thousands of chemicals in the compost.
The EPA is evaluating whether more pollutants need to be regulated, and thinks additional studies are needed, said Lauren Fondal, an environmental engineer for the EPA Office in San Francisco.
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