By Ivan Pereira
The mayor wants the state to look to the tops of buildings to solve the excessive stormwater problems in the city and he used an environmentally friendly school in St. Albans Tuesday to make his point.
Mayor Michael Bloomberg and representatives of the city Department of Environmental Protection visited PS 118, at 190-20 109th Road, which installed a green and blue roof to help control rainwater surges that occur frequently in southeast Queens by collecting the runoff and dispersing the water efficiently.
DEP submitted a proposal to the state Department of Environmental Conservation to create similar roofs around the city as a way of solving the combined sewer overflow, or CSO, a problem that affects all five boroughs.
“The city is obliged by law to reduce the CSOs. We are determined to do that in an environmentally friendly way and also in the most financially responsible way,” Bloomberg said.
The initiative, installed on top of the school’s roof at a cost of more than $300,000, has two components designed to prevent excess stormwater from being collected inside sewers.
Part of the roof has vegetation that acts as a natural collector for the rainwater while the “blue roof” side of the roof uses a surface covered in special stones and mechanical devices to slowly release the stormwater into the streets.
In southeast Queens, a high water table and out-of-date sewers have led to numerous floods during high rainstorms that not only disrupt residents but also cause environmental problems, according to the mayor.
“Unfortunately, stormwater and wastewater combine and are discharged into our waterways,” he said.
The state has mandated that the city use only traditional technology to solve the CSO problem by creating new infrastructure, but the DEP said its green initiative would change DEC’s mind. Bloomberg said the city would save $2.4 billion in costs if it used the roof plan to adhere to the state’s order.
“If what you are going to do is store the water, it would cost an awful lot more than if you were to slowly let it through the system,” he said.
A DEC spokesman said the agency is currently reviewing the city’s proposal but has endorsed the use of green roofs in other parts of New York.
“The department supports the use of green infrastructure and hopes the city’s plans can reduce CSO and storm water runoff,” DEC spokeswoman said.
Reach reporter Ivan Pereira by e-mail at ipereira@cnglocal.com or by phone at 718-260-4546.
