Safety of Biosolid Compost Debated in San Francisco

The end product of composting from biosolids (sewage sludge) is described in an EPA technical paper (?EUR??,,????'??Biosolids Technology Fact Sheet?EUR??,,????'??) as a ?EUR??,,????'??Class A, humus-like material without detectable levels of pathogens that can be applied as a soil conditioner and fertilizer to gardens, food and feed crops and rangelands.?EUR??,,????'?? The worms seem
to like it.

The San Francisco Chronicle reports the San Francisco Public Utilities Commission?EUR??,,????'???s (SFPUC) free monthly distribution of ?EUR??,,????'??biosolid?EUR??,,????'?? compost has caused a debate over its safety.

The biosolid compost, according to the SFPUC, comprises about 20 tons of the 82,000 tons of solid material removed from the city?EUR??,,????'???s sewer every year. This waste goes to a regional composting facility where it is mixed with green yard waste. This brew is heated to 130 degrees for 30 days.

As in all controversies, there are opposing sides. The SFPUC?EUR??,,????'??+the PU in the acronym is unfortunate in this case?EUR??,,????'??+asserts the biosolids are highly treated and heat-pasteurized.

The Organic Consumers Association told the Chronicle the sacks of compost are ?EUR??,,????'??a stew of excrement and toxic chemicals.?EUR??,,????'??

The SFPUC counters that the sewage sludge has been tested for metals and pathogens and is ?EUR??,,????'??basically sterile,?EUR??,,????'?? that the levels of toxins in the compost are well below federal and state standards.

Demonstrating their disdain for the biosolids, representatives from the Washington, D. C.-basedCenter for Food Safety dumped some of it on the steps of San Francisco City Hall on March 4, 2010 and sent Mayor Gavin Newsom a letter claiming the compost contains such hazardous material as heavy metals, pharmaceuticals and flame retardants. The group?EUR??,,????'???s concerns are that children could touch (or swallow) the compost, and that food grown in it could be contaminated.

SFPUC counters that the Center for Food Safety hasn?EUR??,,????'???t released information to back up its assertions of hazardous materials in the compost.

The EPA requires compost be tested for nine pollutants, but that?EUR??,,????'???s about one percent of the hazardous materials that can be found in sewage. Hugh Kaufman, an EPA waste management official, has urged people not to grow food using the compost.

Lauren Fondahl, the biosolids coordinator for the EPA?EUR??,,????'???s Pacific Southwest region, told the Chronicle, ?EUR??,,????'??None of the sewage sludge produced in California has tested hazardous under the national standards.?EUR??,,????'??

Meanwhle SFPUC is conducting comprehensive tests for potentially toxic chemicals in addition to what the EPA requires and will make those
results public.