NEW YORK — New York City Department of Environmental Protection (DEP) Commissioner Carter Strickland announced the expansion of a pilot program to remotely monitor flows inside the sewer system, allowing crews to proactively respond to problems before they can result in sewage backing up into homes and businesses, or onto streets. Last year, DEP installed 21 remote sewer monitoring devices at strategic locations in Queens, Brooklyn, and Staten Island. DEP recently installed 25 additional devices throughout the city and is preparing to install another 18 for a total of 64.
The remote monitoring devices are installed inside manholes and measure the elevation of wastewater in the sewer. That information is transmitted wirelessly to DEP headquarters where it is tracked and analyzed. If the elevation of the wastewater approaches a level that could result in a surcharge or sewer backup, the sensor sends an alert and crews are dispatched to investigate and, if needed, fix the problem. Since the first sewer monitoring devices were installed last year, DEP crews have successfully responded to 129 device alerts, addressing issues that could have resulted in a surcharge or sewer back-ups.
“Remote monitoring of our sewer system is a great example of how we are using technology to make smart investments and maximize the effectiveness of our resources,” said Commissioner Strickland. “A cornerstone of Strategy 2011-2014, our far reaching strategic plan, is to provide the best possible service for our customers at the lowest cost, and this program helps us efficiently deploy our crews.”
DEP is also testing flow monitoring meters that are installed in the bottom of the sewers and measure flow rates. This information, which has never previously been available, will allow engineers to better understand flow rates and identify changes in flow rates that could be a sign of a blockage or some other damage to the sewer. They also facilitate more accurate modeling of the system.
The remote monitoring programs are one component of DEP’s continuing effort to increase proactive maintenance of the sewer system. DEP maintains a robust GIS tool containing digital, searchable maps of all sewer lines, manholes, and other infrastructure to help identify trends and improve preventative maintenance. In 2011, these programs were combined into a single management program that identifies best practices for proactive intervention by field crews. Last year, DEP cleaned nearly 700 miles of sewers, more than double the amount cleaned five years ago.
In December 2012, DEP released its first ever annual State of the Sewers Report. The Report provides an overview of how the City’s sewer system works, DEP’s approach to inspection, cleaning, and repair of the system, a breakdown of the most recurrent causes of sewer blockages, a look at the new employee training facility and safety programs, how advanced analytics, software, and mapping tools are being used to target problematic areas and hydraulic modeling is guiding designs for future capital projects and citywide and borough by borough performance analytics.
Some key city-wide performance statistics from the last five years include:
• Sewer backup complaints have dropped from more than 21,600 to fewer than 13,900, a decrease of 36 percent.
• Confirmed sewer backups have dropped from more than 7,700 to fewer than 4,900, a decrease of 37 percent.
• Less than 1 percent of the city’s nearly 160,000 sewer segments experienced recurring back-ups last year. Once identified, segments that experience recurring back-ups are given high priority for maintenance crews.
• Miles of sewer lines cleaned under our programs that target problematic areas has increased from over 320 miles to almost 700 miles, a 116 percent increase.
• Defective catch basin complaints have dropped from more than 18,000 to 12,370, a 32 percent decrease.
In addition to proactive monitoring and maintenance, DEP’s Executive Budget includes more than $3.7 billion in water and sewer infrastructure investments for Fiscal Years 2014 to 2023 — including nearly $2.2 billion for sewers — of which $353.9 million will fund high-level storm sewers to mitigate combined sewer overflows and sewer backups.