When activists dumped processed sewage compost on the steps of San Francisco City Hall in March, the stunt was meant to draw national attention toward a supposed hypocrisy afoot in the greenest city in America.

San Francisco, activists claimed, was poisoning its residents by giving away “toxic sewage sludge,” a mixture of treated sewage and yard waste for use on home gardens that’s a stew of all that goes down the city’s drains and sewers.

Reeling from the controversy, the San Francisco Public Utilities
Commission immediately suspended the giveaway program and this summer
completed a series of expensive tests in an effort to prove its safety.
Results in hand, the commission pronounced the “biosolids compost,” as
it is officially called, no worse than the packaged fertilizers sold at
commercial garden stores. The giveaway program, however, remains in
limbo until a September commission meeting.

The controversy, which is far from over, is part of a national debate
on what to do with the country’s 3 million dry tons of sewage sludge
produced each year. Proponents see biosolids
as a resource that improves soil nutrients and recycles waste back into
the natural system. Yet a growing number of communities are opposing
the use of biosolids out of fear that it spreads harmful contaminants
and pathogens, and in some cases smells bad.

“Toxic sewage sludge shouldn’t be used, period,” said John Stauber of the newly formed Food Rights Network and author of the 1995 book “Toxic Sludge Is Good for You.” “We’re not talking about human manure. We’re talking about everything that goes down the drain is ending up in sludge.”

In California, concerns have been notably fierce. In Kern
County, the state’s breadbasket, a county ban on the land application of
processed sewage sludge from Los Angeles was upheld by the U.S. Ninth
District Court in a precedent-setting case. (The U.S. Supreme Court refused to take Los Angeles’ appeal in June.)

Inadequate and outdated

Meanwhile, communities like San Francisco that have permitted
its use have been doing so under federal regulations. Some independent
experts, however, say that the U.S. Environment Protection Agency’s
regulatory rule, to which San Francisco is abiding, is inadequate and
outdated.

“The EPA rule came out in 1993 and was based on science from the 1970s and 80s,” said Murray McBride, a soil chemist and head of the Cornell University Waste Management Institute.

McBride, who studies biosolids, said that many other chemical
compounds appearing in the waste are not routinely tested before land
application. The EPA requires testing for nine heavy metals, but not
dangerous and long-lasting chemicals like DDT and PCBs, which have been
phased out for more than three decades but still appear in the
environment.

Nor do the testing requirements take into account a host of emerging chemicals of concern that
have been introduced into the environment in higher concentrations over
time, like endocrine-disrupting flame retardants, phthalates and the
antibacterial agent triclosan.