NEW YORK — Sewage enough to fill 17,000 Olympic-sized pools flowed into public waterways and roadways in the months after superstorm Sandy laid waste to the East Coast, researchers said on Tuesday.
Human waste and dirty water overflowed from waste treatment centers into canals, bays and city streets from the time Sandy hit in late October until January, according to a report by Climate Central, a group that studies climate change.
“[It was] 3.5 billion gallons of untreated raw sewage and 7.5 billion gallons of partially treated sewage that received some filtration and disinfection,” Alyson Kenward, a senior scientist at Climate Central, told reporters on Tuesday.
Six months after the storm killed 159 people, cut off power to millions and caused $70 billion in damage in eight states, the full extent of its wrath is still being measured. Public officials, companies that operate critical infrastructure, and groups such as Climate Central are still examining what went wrong and remains unresolved in the aftermath of the heavy wind, rainfall and tidal surges.
New York Gov. Andrew Cuomo said Tuesday that he has asked power company Con Edison to freeze its executive bonuses until the completion of a review of the performance of local utility companies during storms including Sandy and 2011′s Hurricane Irene.
While most power and sewage treatment facilities that were closed during the storm are up and running again, the damage took a long time to repair. Some areas were left without electricity for months and one sewage facility on Long Island took 44 days to fully restore operations.
The most damaged sewage processing plant, the Passaic Valley Sewerage Commission in Newark, N.J., spewed more than 3 billion gallons of untreated and partially treated sewage in the three weeks it took to fully resume operations.
The last reported incident of sewage overflow was in January, in Middlesex County Sewage Authority in Sayersville, N.J.
It is too early to tell whether the sewage overflows have endangered residents’ health, said Kenward and Climate Central Chief Operating Officer Ben Strauss.
“It’s a wide but diffuse exposure, and assessing the consequences is a notoriously difficult challenge in public health,” Strauss said.
These kinds of incidents will become increasingly common as rising sea levels make treatment plants particularly vulnerable to flooding because they “by design do have to be relatively close to water,” said Kenward.
Lifting power generators and critical sewage processing components higher above ground level, increasing the number of watertight gates around the plants and reviewing emergency protocols might help curb damage from future storms, the researchers said.
Nevertheless, there is a bright spot in the storm’s aftermath — at least for residents of New York City, said Strauss.
The smell of raw sewage, he said, had most likely dissipated within days of the flood, leaving the city smelling no worse than usual.