Wednesday, March 29, 2006

New York City's Role in Cleaning up Long Island Sound

Back in January there was a big hoopla about an agreement that ties New York City to a schedule for upgrading their sewage treatment plants to reduce the amount of nitrogen the city puts into Long Island Sound. This agreement came 10 years after the first agreement requiring the city to do nitrogen removal, and it gave the the city an additional three years to meet its nitrogen removal obligation (from 2014 to 2017). I groused about it at the time but the truth is that New York City is so powerful politically, and it contributes so much to the Sound's problems (80 percent of the nitrogen that causes hypoxia comes from the city), that any ironclad agreement, even one that gives them an extra three years, probably is a good one.

Yesterday I was at Yale, speaking at a class ("Managing the Coastal Nutrient Problem: The Case of Long Island Sound") being offered to students in Yale's School of Forestry and Environmental Sciences (insert your own joke here about the value of a Yale education not being what it used to be), and then stayed to listen to the second speaker, Mark Klein, of the New York City DEP.

In my talk, I said that the city had to be dragged into the Sound cleanup because, compared to the other issues the DEP has to deal with such as drinking water, the Sound isn't that much of a priority for New York City. I pointed out that the part of the Sound that's in the city -- the strip of water west of the Throgs Neck Bridge -- isn't even called Long Island Sound; it's called the East River, which it isn't.

Mark agreed with the competing-interests theory, and said that over the next 10 years the city has earmarked $1 billion in capital improvements for its water supply, $800 million for fixing combined sewer overflows, and $750 million for nitrogen removal at seven treatment plants (four on the Sound, two on the East River, and one in Jamaica Bay).

Mark said that before sewage is treated at the city's plants, nitrogen concentrations are about 30 milligrams per liter. The city has already taken some intermediate steps to reduce that to about 14 milligrams per liter; and by 2017 it will be down to 9 milligrams per liter at three of the four Sound plants and 7 milligrams per liter at the other (Tallmans Island).

That's about a 70 percent nitrogen reduction, well above the 58.5 percent Soundwide goal. Presumably the 70 percent will compensate for nitrogen that conintues to enter the Sound from stormwater from city streets, for example.

In any case, the city has committed a lot of money for capital improvements. And when you add up the CSO and nitrogen removal budgets, it comes to $1.55 billion for water quality. That's impressive, and the 70 percent reduction is impressive. Let's hope they meet the goal.

1 Comments:

Anonymous Robert said...

I think you, or Mark, are comparing two different things for percentage removals. The 30 mg/l in your paragraph (copied below) is for raw wastewater. That is not the basis for the TMDL required reductions. The City's plant's effluent must have been lower than 30 mg/l in nitrogen, even in 1990. I believe NYC is obligated to remove 58.5% and in its case there is no additional alocated nitrogen reduction based upon the estimated nonpoint discharge.

"Mark said that before sewage is treated at the city's plants, nitrogen concentrations are about 30 milligrams per liter. The city has already taken some intermediate steps to reduce that to about 14 milligrams per liter; and by 2017 it will be down to 9 milligrams per liter at three of the four Sound plants and 7 milligrams per liter at the other (Tallmans Island)."

2:43 PM  

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