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San Francisco Has to Do More to Prove Their Sludge is Safe

by: Jill Richardson

Sun Jun 27, 2010 at 21:01:03 PM PDT

San Francisco's Public Utilities Commission (SFPUC) promised to test its "biosolids compost" (i.e. sludge from 9 counties mixed with yard waste and composted) for safety. That was great news. But the results are less than stellar.

Along with a long list of letters (mostly from the sludge lobby) praising its sludge giveaway program, they show test results for a few heavy metals and fecal coliform. Even though sludge contains tens of thousands of chemicals and organisms, the EPA only regulates 10. And that's exactly what they tested for. The problem? The biggest danger in sludge isn't (usually) those 10 regulated toxins. After all, they are regulated! The problem comes from the countless OTHER toxins and pathogens that can occur in sludge.

Jill Richardson :: San Francisco Has to Do More to Prove Their Sludge is Safe

To save you the fun of downloading SFPUC's PDF documents, here's what they found in their sludge:

Arsenic: 4.1200ppm
Cadmium: 2.5800ppm
Cobalt: 2.3100ppm
Mercury: 0.4990ppm
Molybdenum: 5.2000ppm
Nickel: 14.2000ppm
Lead: 25.4000ppm
Selenium: 1.4200ppm
Zinc: 328ppm

They also shared various tests over time for those same elements. Here are the highs and lows found for each element between March 2009 and September 2009:

Arsenic: 2.6ppm-10ppm
Cadmium: 0.9003ppm-7.1ppm
Chromium: 20.8ppm-44ppm
Cobalt: 1.92ppm-4.1ppm
Copper: 140ppm-330ppm
Lead: 13.9ppm-41ppm
Mercury: 0.31ppm-.96ppm
Molybdenum: 2.5ppm-10ppm
Nickel: 10.3ppm-59ppm
Selenium: <1.0ppm-1.42ppm
Zinc: 232ppm-550ppm

Also in Sept 2009, they tested for fecal coliform and found <3 mpn/g. They also tested for salmonella and found <3 mpn/g as well. Interestingly, salmonella was the only thing they tested for that ISN'T regulated by EPA. But what about dioxins, pesticides, PCBs, pharmaceuticals, hormones, steroids, flame retardants and all of the rest of the stuff that can be found in sludge? Where are those tests? What is SFPUC hiding?

Let me be clear about this. It's not as if SFPUC is ignorant. They test their sludge regularly for a loooong list of chemicals. So it's not as if it's never crossed their minds to test their sludge for nasty chemicals outside of the few regulated heavy metals and fecal coliform. They either don't want to test for other toxins and pathogens, or they DID test for them and they don't want us to know what they found. So which is it?

Tags: SFPUC, San Francisco, Biosolids, Sewage Sludge, (All Tags)

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San Francisco Has to Do More to Prove Their Sludge is Safe | 1 comments

This is amazing to me... (4.00 / 2)

I worked in environmental remediation in NJ for over 9 years, and our private laboratory tested for all of this stuff. For the most part, it was to make sure land was clean before ~~building more hideous suburban crap~~ it could be 'redeveloped'.

It can't just be a Northeastern thing, can it? After all, I worked sites in New York, Delaware, Pennsylvania and Connecticut as well as of course New Jersey.

Is K. Hovnanian really held to a higher standard of where and upon what they're allowed to build their shitty subdivisions, than municipal utilities authorities are held to where they're allowed to essentially dump their toxic waste?

by: JayinPhiladelphia @ Mon Jun 28, 2010 at 04:35:57 AM UTC