FOR IMMEDIATE RELEASE10-60
June 16, 2010
Farrell Sklerov / Michael Saucier (718) 595-6600
DEP Debuts Vactor Trucks to Clean City's Sewer System
New Rigs To Help Cut Combined Sewer Overflows by up to 25%
Environmental Protection Commissioner Cas Holloway today demonstrated two Vactor trucks that DEP is placing into service immediately to begin cleaning the city's vast network of sewer lines. With the new $450,000 trucks, DEP will launch a two-year program to systematically clean the largest sewer lines in the city, called interceptors. This cleaning will increase the ability of the interceptors to convey flow to the City's wastewater plants. The new trucks contain a powerful vacuum system that can suck debris and sediment that has accumulated in sewers over the years, reducing the system's ability to convey as much stormwater and wastewater through the pipes as possible during wet weather. Using state-of-the-art sonar technology, DEP estimates that this initiative will help reduce Combined Sewer Overflows by up to 25% in parts of the city where cleaning will have the greatest benefit.
"Making the most of our existing infrastructure is an extremely cost-effective way to improve water quality," said Commissioner Holloway. "Cleaning these sewer pipes will lead to further reductions in Combined Sewer Overflows, and these trucks will give our sewage treatment workers the tools they need to prevent CSOs more effectively than ever before. Reducing the number and severity of overflows will help us open 90 percent of New York City's waterways to recreational use, one of the core goals of PlaNYC, Mayor Bloomberg's blueprint for a sustainable New York City."
"EPA applauds efforts by the New York City Department of Environmental Protection to reduce the amount of debris in city sewers," said Judith Enck, U.S. Environmental Protection Agency Regional Administrator. "These actions to keep the sewer system from becoming clogged will help to reduce water pollution from combined sewers."
"Combined sewer overflows have long been a problem for New York City and other communities across the state and it's important to be proactive in addressing problems. By taking this initiative, Commissioner Holloway is doing just that," said New York State Environmental Conservation Commissioner Pete Grannis.
"Sewage treatment workers do hard and dirty work cleaning these interceptors, but it's important toward improving the City's waterways," said James Tucciarelli, President of Local 1320, which represents sewage treatment workers.
"I commend Commissioner Holloway on his implementation of innovative ideas to ensure that our underground infrastructure functions properly" said Council Member Diana Reyna. "Keeping our sewers clean and our wastewater systems in good repair are of vital importance to the city."
The diesel-powered Vactor trucks use a 30-foot hose to vacuum debris from sewers, which are accessed through manholes that connect to the system. The trucks also have a water jet to clear clogs in the sewer. Sediment and illegally dumped debris can build up over many years in certain areas of the sewer system. Illegally dumped debris can include bricks, tires, mattresses and construction materials. When the Vactor trucks are full, the sediment and debris are transported to the Wards Island Wastewater Treatment Plant in Manhattan, where it is removed from the truck and placed in containers for transport to a landfill. The two trucks now in service can collect up to three tons of sediment and debris each day.
The two Vactor trucks will begin an approximately two-year cycle of a program to clean 136 miles of sewer interceptors. Interceptors are currently cleaned by contractors when they are heavily clogged, and in response to emergencies. Now, interceptor cleaning will become a routine part of daily operations for DEP's in-house forces. Sewer interceptors range from 4 feet to 10 feet in diameter and are the last stop for wastewater flow before it is conveyed to the City's 14 wastewater treatment plants. The interceptors receive wastewater flow from the City's 7,400 miles of trunk sewer mains and lateral sewers, which take flow from homes, businesses and the catch basins on streets.
New Yorkers produce, and DEP treats, more than 1.3 billion gallons of wastewater every day. The wastewater is carried to the City's 14 wastewater treatment plants, which have plenty of capacity to handle 100% of the City's wastewater flow in dry weather, and are designed to handle twice that capacity in wet weather. Two-thirds of New York City has a combined sewer system that collects wastewater and stormwater runoff in the same pipes. This sometimes presents an issue during rainstorms, when treatment plants reach their capacity. To relieve the sewage system during these high-flow periods, the interceptor sewers have "regulators" equipped with overflow weirs that divert combined stormwater and wastewater into New York City's surrounding waterways. This is known as a combined sewer overflow. Upgrades to New York City's plants and sewers have allowed for the capture of a greater amount of overall flow, from about 30% in the 1980s to over 72% today; and overflows are more dilute, with the percentage of sanitary waste decreasing from 30% to about 12% today.
Removing debris in the interceptors, based on DEP's modeling, can yield up to a 25% reduction in Combined Sewer Overflow volume in some areas where cleaning will provide the greatest benefit. DEP is in the process of surveying all the interceptors with sonar imaging to identify levels of any accumulated debris. The schedule for deployment of the Vactor trucks will be based on this analysis. Preliminary results show that some segments of certain interceptors have accumulated enough debris that they are one-third full and prioritized cleaning is expected to provide the greatest benefit. Southeast Queens appears to have the most significant levels of debris of the interceptors inspected thus far, so the first stage of work will begin in the Springfield Gardens, Rosedale and Jamaica sections of Queens, and then move on to the Rockaways. In addition to the two new Vactor trucks being deployed today, DEP has ordered two additional trucks that are scheduled for delivery in 2011.
The Vactor trucks will complement the $1.1 billion in investments planned or underway through 2019 to improve water quality by capturing overflows. These investments are in addition to the approximately $1 billion in Combined Sewer Overflow-related projects that were completed or started construction between 2002 and 2009, including the Flushing Bay and Spring Creek Combined Sewer Overflow Retention Facilities now in operation. Since 2002, the City has invested more than $5 billion to upgrade its 14 wastewater treatment plants. Because of these investments, DEP has achieved a number of milestones recently: reaching City-wide monthly average Clean Water Act secondary treatment standards for the first time ever – three years ahead of schedule; ending Federal probation and monitoring this past December 2009 that began in 2001; and agreeing to a historic nitrogen-reduction program for Jamaica Bay with the State Department of Environmental Conservation and the Natural Resources Defense Council.
DEP manages the City's water supply, providing more than 1 billion gallons of water each day to more than 9 million residents, including 8 million in New York City, and residents of Ulster, Orange, Putnam and Westchester counties. Approximately 7,000 miles of water mains, tunnels and aqueducts bring water to homes and businesses throughout the five boroughs, and 7,400 miles of sewer lines take wastewater to 14 in-City treatment plants. DEP also manages storm water throughout the City, and ensures that the City's facilities comply with the Clean Water Act, and other federal, state and local rules and regulations.