Sludge Watch ==> Washington State County posts warning signs on sludged forests - concerns remain

[Maureen Reilly]

Sludgewatch Admin:

Biosolids: A help or a hazard?
Lets parse that a bit....
Sure land application of sludge has been a cheap way to dispose of 
industrial and muncipal wastes...there is your 'help'
And then there is the hazard to the health of people, animals, biota, and 
crops who may come into contact with the
unknown combination of chemicals and drugs, and pathogens that can be found 
in sludge.

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Biosolids: A help or a hazard?




Gary Kissel/Journal
GroCo under processing is turned for the fourth time at Sawdust Supply Co. 
in Kent. After five turns, GroCo, a soil supplement made from the solids 
left over from sewage treatment, is ready to be used to enhance growth in 
forests, crops and gardens.







By Dean A. Radford
Journal Reporter


Most if not all of the roughly 110,000 wet tons of solids left over from 
treating sewage at county plants in Renton and Seattle each year are being 
used to make things grow.

Given that these biosolids are highly treated to meet and often beat federal 
and state standards, it's not too hard to get over the inevitable "ick" 
factor.

But there has been a national debate for years over the use of biosolids on 
farmlands and forests. In some places the practice is banned because there 
is a question about the impact they could have on the environment and human 
health.

King County officials point out, however, that biosolids have been studied 
for years, providing assurances that their application on agricultural soils 
and forests is safe.

Counties in Washington state had no choice but to make good environmental 
use of the sludge from the sewage-treatment plants.

In the mid-1990s, the Legislature banned biosolids from landfills, meaning 
counties had to find another use for them, typically spreading them over 
forests and fallow farmlands.

For 30 years, the county has had programs to recycle biosolids.

These biosolids are used to nourish trees at the Snoqualmie Tree Farm in 
eastern King County and wheat in Eastern Washington.

And gardeners are making their lawns green and their petunias grow with a 
product called GroCo, a highly treated soil conditioner made with sawdust 
and those biosolids. GroCo is sold in bulk to developers and to cities that 
use it in their parks.

GroCo has been made for about 30 years, using mostly biosolids from the 
county's treatment plants. Its sales suffered for a time years ago when 
someone back East claimed - incorrectly, it turned out - that biosolids 
caused Lou Gehrig's disease.

Still, L.D. "Curley" Winebrenner, GroCo Inc.'s special projects manager, 
said people have "a love-hate relationship" with biosolids.

"They will stand up to their knees in SteerCo (another company product that 
uses cattle manure). But if you put a fleck of GroCo on them, they'll have 
to go wash," he said.

"It's perception," Winebrenner said.

The biosolids used to make GroCo come treated by the county. Among other 
things, digesters reduce the amount of organic materials, pathogens and 
materials that cause the solids to stink.

Then GroCo further treats the biosolids as it mixes them with sawdust in a 
composting-like process. In that process, temperatures reach at least 133 
degrees, which kills bacteria, too.

For years, companies ranging from The Boeing Co. to photo-processing 
businesses have been required to pre-treat their wastes before discharging 
anything into the sewage system. Even dentists must ensure that mercury in 
dental products doesn't reach the waste stream.

"Those are all regulated by federal and state governments, so the 
pre-treatment has to take place to a certain standard level," according to 
Greg Bush, the county's Wastewater Treatment Division manager for planning 
and compliance.

Still, the research continues on the treatment and application of biosolids 
and what kinds of chemicals or metals that they contain, including a study 
led by an Eastern Washington University researcher in Cheney.

The research led by Chad Kinney, an assistant professor of chemistry and 
biochemistry at Eastern, found pharmaceutical, industrial and household 
compounds in nine biosolid products from around the country.

Kinney called the research "a starting point" to determine the range of 
compounds found in such products. But questions remain, he said, including 
what happens to these compounds once they enter the environment and what 
effects they have on animal and plant life.

But, he said, "biosolids likely represent a route for these compounds to get 
into the environment."

Roberta King, the county's biosolids project manager, said such research 
should continue, but she doesn't think the studies done to date "are cause 
for alarm." She said that some chemical compounds bind with biosolids, in 
essence keeping them from moving into the environment.

Bush, the county manager, said that research also shows plants are not 
taking up any of the compounds in the biosolids, other than the nutrients, 
including the all-important nitrogen.

Other research, according to King, showed very little chance that compounds 
can become airborne and leave the application site.

Close to home, questions are occasionally asked whether any compounds are 
leaving such application sites as the Snoqualmie Tree Farm. There is at 
least one unconfirmed report of dead fish and frogs in lakes nearby and a 
sludge-like substance on rocks. Some believe that biosolids are to blame.

But Kinney said that such conclusions can't be drawn until the source and 
type of contaminants are identified and studies done. Synthetic contaminants 
are found in remote areas, perhaps blown there by the wind, he said.

The county is required to post warning signs around forest and agricultural 
lands where the biosolids are applied. The bulk of potential disease-causing 
bacteria have been killed, but the county still doesn't want people to 
picnic in the area or inhale the material, King said.



Dean Radford covers King County. He can be reached at 
dean.radford at kingcountyjournal.com or 253-872-6719.
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