City officials are now facing a deadline to figure out why the sewer system is sometimes overwhelmed.
The City Council has approved a consent order with the state Department of Environmental Conservation, promising to find the problem within the next three months and then resolve it within three years.
Given that the city has been searching for the problem for years, it’s a tight schedule, but city officials knew this was coming. They hired a company in December to begin investigative work when they could not figure it out on their own.
“We were proactive,” said Paul Lafond, deputy director of water and wastewater.
That company, CDM Smith, has now installed a dozen flow-monitoring devices in sewer pipes near the river and onward to the sewage plant. The “strong suspicion” is that the river is somehow flowing into an unsealed pipe, Lafond said.
That’s because the system gets overwhelmed with water during rain storms when the river is high. In those situations, city workers release some untreated sewage into the river to relieve the strain on the system. DEC wants the city to stop doing that, which is why the agency insisted on a consent order to get the problem solved.
If the river is low, the system doesn’t get overwhelmed — even in severe rain.
City officials searched for pipes near the river, and they’re still looking for a forgotten outlet pipe that could be accepting water.
“That’s a very strong possibility,” Lafond said.
City crews found one such pipe on Mohawk Avenue years ago, he added. The pipe was an old overflow pipe that could send untreated sewage directly into the river below. When the river rose, water could flow into it, too.
“Once we found it, we sealed it up,” he said, adding that if there was one, there could be others.
The monitors will show where the water flow spikes, to help in “putting the puzzle together,” he said.
The city is also tracking the weather, inches of rain per hour and the height of the river for the next two months. All that should help pinpoint the problem.
“We need to get enough data during wet and dry weather events. We haven’t had much wet weather yet,” Lafond said.