Sewer Break Pours 2M Gallons Of Sewage Into River; Swimming, Fishing Discouraged

Thanks to a corroded sewer pipe, millions of gallons of sewage flowed into the Mill River on Monday, and the Greater New Haven Water Pollution Control Authority (WPCA) had to scramble to stop the spill and reroute the sewer while it fixes a collapsed sewer main.

At a press conference Wednesday morning, New Haven officials urged people not to swim or fish in the Mill River or Lighthouse Point Park.

Mayor Justin Elicker said the problem does not affect drinking water.

Branford and East Haven also closed their beaches Wednesday because of the spill.

The problem started early Monday morning, though the WPCA apparently did not notify New Haven officials of the severity of it for more than a day. (See more below on that press conference, and on an interview with someone who was out hunting for crabs on the Mill River Wednesday afternoon.)

At about 5 a.m. Monday, the WPCA started getting calls about sewage spilling onto Whitney Avenue near the intersection with Armory Street. Crews were out by 6. By 9:30 p.m., they had finally stopped the spill by diverting the sewer line through a temporary 8‑inch pipe, but not before 2.1 million gallons had spilled onto the street, into storm drains, and into the Mill River.

Luckily, the WPCA was already working at the site. A few weeks ago, it received a notification through the See Click Fix app that there was a hole in the ground along Whitney Avenue and that flowing sewage was visible through it.

On Monday, the authority and its contractors had already brought in the heavy equipment and begun the work of diverting the sewer line in order to fix the hole. They were still setting up a series of pipes to divert the sewer flow so they could fix the main.

Unlike a water main, a sewer pipe is not pressurized. Pipes are generally half full, so when a hole forms in the top of a pipe, the sewage can still flow, and doesn’t burst out like it would in a water main. But dirt and rocks and other debris can fall into the hole, causing more problems.

Sometime likely in the wee hours of Monday morning, the hole, which up until that point had not blocked the flow of the sewer, collapsed, blocking the pipe. Sewage flowed up out of the ground and spilled onto Whitney Avenue. It flowed down the hill to storm drains at the low point of the road in front of the Eli Whitney Museum, and then flowed from there into the nearby Mill River.

The line that runs beneath Whitney Avenue is a 30-inch main that flows all the way from Quinnipiac University in Hamden to the waste water treatment plant near the waterfront in New Haven. It flows downhill the whole way, meaning no pumps are necessary to keep the sewage moving. It carries an average of about 3 million gallons every day.

The break happened in a particularly difficult place, said WPCA Director of Operations Gary Zrelak (pictured). In other places, manhole covers are located closer together, meaning it’s easier to bypass a section of pipe when there’s a problem. But the closest manhole cover is 2,100 feet from the break, on East Rock Park Road.

When the collapse happened, workers were close to completing the planned diversion of the pipe, but were not done yet. That meant workers had to use a smaller 8‑inch pipe to carry sewage from the break to the manhole cover on East Rock Park Road. Zrelak said crews managed to complete it by 9:30 p.m. Monday.

Throughout Monday, workers scrambled to create that emergency bypass and also mitigate the effects of the spill. They treated the sewage as best they could with sodium hypochlorite — essentially bleach — to avoid causing a health emergency. They also used vacuum trucks to suck about 500,000 gallons of sewage and carry it down to a manhole cover on Livingston Street and dump it back into the sewer line further downstream.

Sulfuric Acid To Blame

The line beneath Whitney is made of concrete, and was built in 1966. In general, it has held up, but the spot where the break occurred is an especially tricky one.

These types of holes are often caused by erosion from sulfuric acid, Zrelak said. Sewage contains a lot of sulfur, he explained. When the sulfur in sewage is exposed to moist air, as it is in the upper part of a pipe, it reacts and becomes corrosive sulfuric acid. This happens in places where there is turbulence in the pipe, and where the sewage comes in contact with air.

The site of the collapse is at the top of a downward slope, meaning the level of the sewage is relatively low, but it is beginning to move faster, mixing it up with more air, creating the perfect conditions for sulfuric acid formation.

The WPCA inspects its pipes for these breaks periodically. In order to do so, it has to send a camera through the pipe. The stretch of pipe where Monday’s break occurred was last inspected in 2015.

Minor sinkholes are common, said WPCA Director of Engineering Thomas Sgroi. But major collapses like Monday’s are rare, he said. They might happen once every two or three years. In general, the system’s 550 miles of sewer is in pretty good shape, he said.

The crew was lucky that it had already completed much of the work to divert the flow of the line so it can work on repairing it. By Tuesday afternoon, it had already transferred flow to a much larger temporary bypass than the small 8‑inch emergency one.

Up above the collapse, two large pumps where attached to the sewer line, and pumped sewage into the temporary pipe. That pipe carried it to just below the break, where it then deposited the sewage back into the regular main.

Crews had drilled large holes in the top of the pipe to attach the bypass. That drilling takes four hours, said Zrelak. The cores of the concrete were still sitting on the dirt. Those sections were in good shape, he said, pointing out how they are thick and un-corroded.

As Zrelak showed the various parts of the diversion system, he looked over at Lake Whitney, whose waters lapped the barrier a few feet away from the sidewalk on which he was standing. Lake Whitney provides water for the New Haven area.

“We just have to thank God it wasn’t higher up,” he said, gesturing at the lake. Luckily, the break was downstream of the city’s water supply. ​“That keeps me up at night.”

Communication Delay

Zrelak joined Mayor Elicker (pictured) and city Health Director Maritza Bond for a Wednesday morning press conference on the second floor of City Hall to talk about the sewage leak — and about what steps the WPCA took to notify the city after the leak took place.

Zrelak said that the WPCA followed state Department of Energy and Environmental Protection (DEEP) guidelines by reporting the sewage bypass to the state within two hours of it occurring. He said the WPCA also worked closely with Hamden police, public works, and health officials to block off the area where the leak occurred by the Whitney Dam so that the WPCA could work on fixing the pipe.

When asked about what kind of communication the WPCA had with New Haven city officials, Zrelak said, ​“We always need to emphasize the order of magnitude. I think that’s where there was some loss of communication.” He said that the WPCA was in such close contact with Hamden officials because the sewage leak happened in Hamden.

“We were notified about a small leak and we were not notified about the extent of the problem,” Elicker said. He said that he received an initial notification from the WPCA on Monday, but didn’t realize the scale of the problem until Tuesday evening — when he was walking his dog through East Rock Park and some kids approached him and said there was a bunch of dead fish in the river. That’s when Elicker got in touch with the WPCA to better understand what had happened, how much sewage had spilled out, and then the city sent out a robocall to city residents about the leak.

“I don’t think anyone was trying to minimize it,” Zrelak said about the delayed communication with New Haven.

Bond (pictured) said that the city is strongly recommending that people not fish or swim in the Mill River or at Lighthouse Point Park. She said the city will be testing the water at Lighthouse Point twice a week for the foreseeable future to make sure that it is safe for people to swim.

When asked what symptoms New Haveners should look out for if they are in contact with water from the Mill River, Bond said, ​“If they’re experiencing nausea, vomiting, fever, they should contact their health care provider.”

“I’ll Still Eat Them”

Despite the recent sewage spill, 64-year-old Hill resident and amateur fisherman Tony Alvarado was out on Grand Avenue Wednesday early afternoon, hunting for crabs in the Mill River.

He told the Independent that he spends most summer days on the bridge that overlooks the Mill River and the defunct English Power Plant, trying to catch crabs in a crab trap baited with a piece of raw chicken thigh wrapped in metallic wire.

He caught a crab Wednesday morning and showed it off with pride.

Alvarado said he heard about the sewage leak on Tuesday, but came out to hunt for crabs anyway.

“I’ll still eat them,” he said about the day’s catch. ​“They always say they got germs, but remember, once we put it in water, they boil. And when you boil them, and you put your hand in, psssh, it’s gone!”

When asked if he planned to eat the crab he caught in the sewage-polluted river, he said, ​“If I ain’t gonna eat it, I wouldn’t be here.”

Bond reiterated for the Independent later Wednesday afternoon that she strongly discourages people from fishing or crab catching on the Mill River at this time.

She said that people are incorrect to assume that boiling crabs in water will protect them from all of the bacteria they might have picked up because of a sewage spill.

“That’s a misconception,” she said. ​“Please avoid eating any fish or crab caught in the river until further notice.”