Greenwire: A San Francisco program that taps 20 tons of solid human waste from the city’s sewage each year to be transformed into backyard compost is being vehemently opposed by a national environmental group that says the initiative is leading to toxic dumps in people’s backyards.
At issue is a program spearheaded by the San Francisco Public Utilities Commission that provides free biosolid compost — drawn from a portion of the city’s 82,000 tons of solid sewage waste — to gardeners, school groups and homeowners. The commission says the compost is heat-treated fertilizer and that it is as good as any store-sold counterpart.
But the Organic Consumers Association, which opposes the program, says children and others who touch the compost might swallow or absorb chemicals into their bloodstreams. They also are concerned that food grown in the human waste-based fertilizer could be contaminated.
“The problem with sewage sludge or the euphemistic term ‘biosolids’ that they use is that all of this is hazardous material that potentially contains thousands and thousands of contaminants,” said John Stauber, a member of the Organic Consumers Association’s advisory board and the author of several articles and a book on sewage sludge.
The commission maintains that the levels of toxins found in the compost do not exceed federal and state standards. “It has been tested for metals and pathogens and is basically sterile,” said Tyrone Jue, spokesman for the commission. But U.S. EPA mandates the compost be tested for nine pollutants — 1 percent of the hazardous materials that can be found in sewage — and does not require it be tested for dioxins, flame retardants and PCBs.
Stauber said tests conducted by his organization found dioxins, flame retardants and other chemicals in the compost, but his group has not released those results.
The three-year-old program has fueled public controversy, and the consumers association, alongside the nonprofit group the Center for Food Safety, dumped some of the compost on the steps of City Hall last month in protest. The groups also sent a letter to Mayor Gavin Newsom demanding he stop the biosolid handouts. And last week the group picketed Chez Panisse restaurant in Berkeley for allegedly ignoring the problem, targeting it since its founder Alice Waters is also a PUC commissioner.
Experts including EPA waste management official Hugh Kaufman have said people should not grow food in the sewage sludge, but one EPA expert said there is no evidence that city residents are in any kind of danger if they use the compost.
Scientists from the agency are conducting studies to discern whether other chemicals should be tested in the compost (Peter Fimrite, San Francisco Chronicle, April 7). – DFM