Sludge Watch ==> Baltimore - down to sewer or out to trash?

[Maureen Reilly]

Sludgewatch Admin:

This colorful little commentary asks should you put food waste down the sink 
to the sewer or out with the trash in Baltmore. Baltimore has Synagro firing 
up a 900 degree furnace to dry out their sludge pellets that will be used by 
a cement kiln to make fuel.

?HuH?  The taxpayers pay the expensive natural gas bill to dry their sewage 
so Synagro can get paid to put it in a cement kiln ?  And what about the 
mercury in the sludge that is all released into the air throughout this 
process?  Why is it going to a cement kiln?  Because people are not inclined 
to buy sludge pellets...for good reason.

What foolishness.
Put your banana peels in the compost out back.

.......................................................


opinion
Editorial Notebook
Down, or out?

Originally published January 6, 2007

The riddle of the banana peel: You're standing in the kitchen, with a banana 
in one hand and the peel in the other, and before you can eat the banana you 
have to decide what to do with the peel. The sink disposal, or the garbage 
can?
One is easier than the other, one is quieter. But which one is better? Which 
puts the least strain on the environment?


(So, OK, composting would be better than either, but put that aside for now; 
a lot of people lack the yard space for compost, and others lack the will.)

The people at Baltimore's Department of Public Works aren't going to tell 
you what to do; they're fine with both methods. But they're happy to 
describe what each entails.

You talk to Robert Mohr, division chief for waste water facilities, and he 
tells you that after your chopped up banana peel has been carried through 
the city's sewers to either the Back River or Patapsco wastewater treatment 
plants, it passes through a filter and a sedimentation tank before it comes 
to what he calls the activated sludge process.

Microbes feast on it (and in doing so they take nitrogen, which comes from 
other sources, out of the mixture). Clumping together, they begin settling 
out as sludge. This goes to an anaerobic digester, which extracts methane; 
some is used to heat the building, and the rest is flared off, though the 
city has plans to use it to generate electricity.

The rest of the sludge goes to a dryer, where its moisture content is 
reduced from 80 percent to 5 percent, and then it is converted to pellets by 
a private company called Synagro. The pellets are used as fertilizer and are 
being experimented with as a fuel source for a Lehigh Cement plant in 
Carroll County. The biggest use of energy in this whole process is in the 
900-degree, natural gas-fired dryer.

Then you talk to Joe Odziejski, head of the bureau of solid waste, and he 
tells you what happens when you put your banana peel out back for the 
garbage pickup. More than 90 percent of the city's household trash (and a 
lot from Baltimore County, too) goes to the BRESCO plant off Russell Street. 
Every week, the city's garbage trucks go about 6,000 miles, at four miles to 
the gallon. That's about 75,000 gallons of fuel annually.

At BRESCO, which gets $33 a ton from the city, everything flammable (and 
that includes banana peels) is incinerated to make steam - about 4 million 
pounds a year. (You realize you didn't know that steam was measured in 
pounds.) Some goes to heat buildings downtown, and the rest is used to crank 
out electricity - nearly 300,000 megawatts.

Any household trash that doesn't go to BRESCO ends up at the Quarantine Road 
landfill, where rotting banana peels and other garbage produce methane; the 
city will soon be capturing it and selling it to the Coast Guard shipyard 
nearby, for $200,000 a year.

So which is better? Both methods give something back - fertilizer or heat or 
power. The wastewater system is cheaper to run, with 522 employees against 
solid waste's 1,008, and with no plastic bags or trucking involved (though 
there is that little jot of electricity to run the disposal). The emissions 
controls on the BRESCO plant are complex, expensive and imperfect.

But the sewage treatment plants have drawbacks, too. Back River removes just 
70 percent of the nitrogen, a major source of bay pollution, and Patapsco 
gets only 31 percent. Kim Coble, Maryland executive director of the 
Chesapeake Bay Foundation, says the issue isn't the banana peel itself, 
which is mostly carbon and oxygen, but the extra load it puts on the plants: 
The more sewage there is, the faster it moves through the process and the 
more polluted the discharge water will be when it is released into the 
river.

At the same time, a study by New York City, which once banned disposals, 
found that they typically increase household water usage by about a gallon a 
day; that's not much.

In the end, it's your call. It would be interesting to know how other people 
come down on this. Here's a vote for garbage collection: At least it gives 
you a chance to walk to the alley and back, get some exercise and maybe even 
meet a neighbor. Just don't slip on the banana peel on your way out there.

- Will Englund

http://www.baltimoresun.com/news/opinion/bal-ed.notebook06jan06,0,5479921.story?coll=bal-opinion-headlines