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 bio-solids compost" to all takers.
But hold on there.
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 bio-solids compost.
Several cities in California have bio-solid compost giveaways, including Los Angeles, San Juan Capistrano, Santa Rosa, Fortuna, Carlsbad, and Calabasas, according to the Organic Consumers Association.
Sewage or bio-solids compost is also packaged and sold in major house and garden centers across the country.
'Greenest large city'
Fertilizer made from bio-solids 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 bio-solids 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," Cummins said.
But The San Francisco Public Utilities Commission, 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."
Testing for chemicals
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 if more pollutants need to be regulated, and believes additional studies are needed, said Lauren Fondal, an environmental engineer for the EPA office in San Francisco.
"I don't believe there have been any major studies of all these chemicals that we've begun detecting," she said.
There is no hard science that bio-solids compost is perfectly safe, the organic groups say, while there is anecdotal evidence that it is not.
In 2008, for example, a federal judge in Georgia ruled in favor of farmers who sued the United States Department of Agriculture when their cows became ill and died after eating silage grown on land upon which the compost had been applied.
U.S. District Court Judge Anthony Alaimo concluded that "the EPA cannot assure the public that current land application practices are protective of human health and the environment."
'Organic' or not?
Last fall, The Center for Food Safety, a watchdog group with offices in Washington, D.C., and San Francisco, tried to raise awareness of the bio-solids issue when it petitioned San Francisco to end the compost giveaways.
The city made no promises. But the PUC did stop calling its free compost "organic." Under USDA rules, no sewage sludge compost, or farms that use bio-solids, can be called "organic."
On Thursday, when the Minnesota-based members of The Organic Consumer Association held their "toxic sludge giveback" at City Hall, five protesters were flanked by about a dozen reporters and curious passersby.
One of those watching was Jue of the PUC. He said that the city still considers the compost giveaways a pilot project. The city has held six giveaways since 2007. Jue said none are planned for the near future.
"Of course, if the public doesn't want it, we'll stop," he said.