According to the New York State Department of Environmental Protection (DEP), about 10% of CSO in the United States are from New York State. PlaNYC has a number of initiatives to resolve the problem of CSO.
First, the city plans to submit a LTCP (long term control plan), as mandated by the DEP. The LTCP will tackle CSO and help the city comply with regulations. The plans include making new holding tanks, and “optimizing” the existing infrastructures. As part of its LTCP, the city also plans on aeration (pushing oxygen into water to get more plant growth), destratification (churning water to made sure oxygen is distributed evenly), optimization of sewer plants (making sure the most possible sewage is being sent), force mains (forcing CSO out from tributaries and into larger bodies of water that can better “assimilate” CSOs), and dredging (removing the gunk from the bottom of our waters).
The city has completed its LTCP for the fourteen wastewater treatment plants around New York City, and is beginning its LTCP for Coney Island Creek, Gowanus Canal, and Alley Creek. The LTCP provide details about the city’s plans to reduce CSO, and is mandated by law. However, the LTCP is only one aspect of CSO-reduction: It is merely the paperwork that will lead to action.
Second, the city plans to straight reduce CSOs by increasing the amount of water a sewage plant can hold during rain. Currently, all plants must be able to process double the amount of water NYC gets on a non-rainy day. The city plans to expand sewage facilities at three waste-water treatment plants.
The Newton Creek wastewater treatment plant’s expansion from 620 million gallons per day (mgd) to 700 mgd. It services a population of 1,068,012 people. The 26 Ward wastewater treatment plant’s planned expansion to 220 mgd from 170 mgd has been delayed, because of budget cuts. The 26 Ward services around 283,428 people. The city’s eventual plan is to reduce CSO to at least 185 million gallons per day during rain events. Plans for the Jamaica wastewater treatment plant (serving a population of around 728,123 people) have been shelved until the LTCP can be completed.
The third initiative will keep storm water from entering sewage plants, by using more HLSS (High Level Storm Sewers). HLSS divert storm waters so they never gets into the plant; they goes straight out to sea, thus lessing the amount of CSO. HLSS will help prevent street flooding, but require an outlet to a body of water.
Because HLSS must be located near a body of water, their use has been proposed for Hudson Yards and Manahttanville, Mahnattan; Throgs Neck, the Bronx; Gowanus, Brooklyn; and the Laurelton area of Queens. Currently three locations (Laurelton, Throgs Neck, and Gowanus) have drainage plans.
The fourth initiative will increase green space within the city. Current green spaces — including trees and soil — absorb over 800 million gallons of water a year, but between 1984 (a bad year not just for Orwell, apparently) and 2002, about 9,000 acres of vegetation were lost in NYC. The city has proposed an increase number of Greenstreets by 40 to over 3,000 by 2030. All the greenery will absorb storm water and prevent it from flooding the sewer system and causing CSO. In conjunction with this, the city plans to increase efforts to protect wetlands.
The city has constructed 224 new Green Streets. Because of budget cuts, the planned creation of 640 Green Streets by 2019 was reduced to 320.The city has studied federal and state laws to assist in the drafting of a wetlands protection policy. However, nothing beyond the actual studying has been done.
The city also plans to green parking lots by planting trees on the periphery of lots that would otherwise be concrete jungles. The trees will minimize storm water by absorbing rain, instead of letting it flow along sidewalks and into the drains. The city plans to regulate and mandate the planting of trees with zoning laws.
In 2007, the Commercial and Community Facility Parking Lot Text Amendment was approved. It mandates street trees be planted for parking lots with over 18 spots, and also requires a number of bicycle parking spots within the lots. In addition, shrubbery and ornamental trees must be used to provide a buffer around the perimeter of the lot.
And last, the city will provide incentives for green roofs. Green roofs, which are roofs layered with vegetation, can reduce CSOs if many of them are concentrated in one area. Green roofs are also expensive — hence the monetary incentives. There are also incentives for gray water (reusing water from showers and sinks for toilets and gardens).
The Green Roof Abatement tax reduction program was signed into law in 2008, with a abatement of $4.50 per square foot of green roof. The program will end in 2013.
All references last accessed April 10, 2010
PlaNYC Progress Report 2010, Mayor’s Ofﬁce of Long-Term Planning & Sustainability, 2010. Web-PDF. http://www.nyc.gov/html/planyc2030/downloads/pdf/planyc_progress_report_2010.pdf
“Commercial and Community Facility Parking Lot Text Amendment-Approved,” New York City Department of City Planning. Web. http://www.nyc.gov/html/dcp/html/parking_lots/index.shtml
Cohen, S. “Zoning the Sustainable City,” The New York Observer, 2009. Web. http://www.observer.com/2009/zoning-sustainable-city
Green Roof Tax Abatement Program, 2008. Web-PDF. http://www.nyc.gov/html/dof/html/pdf/08pdf/green_roof_legislation.pdf
“Tax Reduction Programs,” NYC Finance-Property. Web. http://www.nyc.gov/html/dof/html/property/property_tax_reduc_taxreductions.shtml
Table of contents:
o CSO in NYC
• Combined Sewer System
• Eliminating CSO
o Drinking Water in NYC
• Buried Streams