Sludge Watch ==> Oregon - sludge on pasture or sludge for fuel?

[Maureen Reilly]

Sludgewatch Admin:

This story looks at whether Portland Oregon should continue to put sludge on 
pasture land and on canola crops, or whether they should use the sludge for 
energy.

Sludge on pasture land is one of the most dangerous disposal methods, since 
the sludge is generally top dressed on the fields, and cattle ingest the top 
layers of dirt while they graze...bring the pharmacuticals, perisistant 
metals, endocrine disruptors and pathogens right into the livestock, where 
they can enter meat and milk, and can cause problems in the development of 
foetuses in sludge-grazed livestock.

The sludge farmer is wrong about greenhouse gases.  Using sludge for fuel 
reduces the levels of greenhouse gas, while land application results in the 
release of as much as 34 pounds per ton of methane, a potent greenhouse gas.


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http://www.portlandtribune.com/news/story.php?story_id=118704567835459500

Sewer sludge looks sweet to some
Farmer uses waste as fertilizer, but firm would burn it for fuel

By Lee van der Voo

The Portland Tribune, Aug 14, 2007
(news photo)

Sarah Toor / P0RTLAND TRIBUNE

Polaris Renewable Energy would like to buy sewer sludge from the Bureau of 
Environmental Services and burn it as an energy source. Currently, the 
sludge is trucked to an Eastern Oregon farmer, who uses it for fertilizer.

A company specializing in renewable energy is in talks with the city of 
Portland to turn the population’s collective sewage sludge into fuel, a 
conversation that’s pitting the firm against an Eastern Oregon farmer who is 
getting paid by the city to use the material as fertilizer.

The details of exactly what Polaris Renewable Energy proposes to do with 
Portland’s collective sewage are proprietary, according to Polaris 
officials. But Christian Frison, a co-founder of Polaris, said the company’s 
plan would use waste heat to dry out the sludge, then use the dry biosolids 
to fuel a generator that could provide power for a local private 
manufacturer.

Polaris is sweetening the pot by offering to make Portland its headquarters 
if the city agrees to pay it to take 30 percent to 50 percent of the roughly 
75,000 tons of biosolids produced here annually.

The business of taking on sludge for a profit is a lucrative one. Last year 
the city of Portland paid $2.5 million to get rid of its sewage by trucking 
six to eight trailers of sludge a day to Madison Farms, a 17,500-acre farm 
in Echo.

There, the sludge is sun-dried and spread over grazing land for cattle and 
also is used on canola crops that make biofuel. Some of that $2.5 million 
went for trucking and fuel costs; most of it went to Madison Farms.

City Commissioner Sam Adams said the Polaris proposal is being evaluated by 
a technical team. He said he sees advantages to bringing Polaris to Portland 
if the price is right, and if the company’s technology proves greener than 
coal and hogfuel.

“As long as we’re protecting the financial interests of the ratepayers, it 
would be great to be able to kickstart a new industry here,” Adams said.

Frison said the Polaris technology is friendlier to the environment than the 
city’s current biosolid management plan. But Kent Madison, owner of Madison 
Farms, said the Polaris proposal would release greenhouse gases by burning 
the carbon in the biosolids and would cost the city more without providing 
agricultural benefits.

Dean Marriott, director of Portland’s Bureau of Environmental Services, said 
the city hasn’t yet determined whether the Polaris plan is environmentally 
friendly.

“Our view is it’s an interesting proposal, one that we’re taking seriously 
and will continue to evaluate,” Marriott said. “We’re talking about two 
different processes: One is used as a fertilizer, and one is used as an 
energy source. … It’s a little hard to line them up side by side and say, 
oh, this one is better.”

Polaris proposes to use less energy to transport the sludge by partnering 
with an unnamed local industry, replacing coal use at industrial generators. 
Frison said the technology also can control hazardous chemicals left in the 
sludge.

Portland’s sewage treatment isn’t designed to treat metals that flow to the 
system from industry and residences. Arsenic, cadmium, chromium, copper, 
lead, mercury, molybdenum, nickel, selenium, silver, zinc and cyanide are 
all present in Portland sewage, as well as pharmaceutical chemicals.

Some of the metals end up in the Columbia River; the rest remain with the 
sewer sludge at the bottom of the tanks at the Columbia Boulevard Wastewater 
Treatment Plant.

Madison Farms tills the metals into the ground, where they are absorbed in 
trace amounts into wheat grown for cattle grazing and canola for biofuel.

Madison said the metals are spread thin – about 3 or 4 dried tons of 
biosolid are spread per acre – and still are found in lower levels in his 
farm’s desert soil than they are most other places in the nation.

“The land application of biosolids, in my opinion, is by far the best thing 
we can do with it,” Madison said.

While trucks to his facility use 80,000 gallons of diesel each year, Madison 
said, not burning the biosolids means that carbon equal to 2.3 million 
gallons worth of diesel is contained. Spreading the biosolids also adds 
micronutrients to the dry soil.

“If you took those biosolids and burned them, you’re not putting anything 
back into the cycle,” he said.

Frison said Polaris isn’t trying to compete with applicators like Madison 
Farms, but he said offering a renewable fuel supply to industries could 
offset coal use at those facilities.

“Our focus is renewable energy generation, and our process can do that 
unlike any other company in the U.S., or process,” he said.

Frison said the company is not asking Portland to assume any risk or build 
facilities. He said Polaris is privately funded and has a technology partner 
with similar operations in Europe. The company also is affiliated with 
BacGen Technologies, an engineering firm.