Equipment regulating an underwater power transmission line that serves Martha’s Vineyard failed under heavy demand Tuesday afternoon, causing the Edgartown wastewater treatment plant to shut down. Sewage backed up into the basement of the 2 Main Street building that houses the Atlantic, a restaurant, and the Boathouse, a private social club. All the food, liquor, and equipment stored in the basement were destroyed.
The sewage pumps on many Edgartown homes slowed down and sounded alarms. The wastewater district received about 60 calls from residents concerned with the alarms. According to sewage treatment plant manager Joe Alosso, the pumps in private homes kept working, though slowly, and no sewage backups were reported in private homes. Homeowners were asked to use as little water as possible, until the problem was resolved.
NSTAR spokesman Mike Durand said a voltage regulator, designed to keep the Island’s supply of power even and consistent, failed late in the afternoon, during a heavy demand for electricity on a very hot day.
“We attempted to make a correction,” Mr. Durand said Wednesday in a phone conversation with The Times. “The correction didn’t have the effect we needed, so we made another change, and that corrected the problem.” The power dip lasted about one hour.
At the wastewater treatment plant, voltage dropped from the normal supply of 480 volts, down to 335 volts. “That wasn’t low enough to kick on our emergency generators, but it was low enough to shut the station down,” said Mr. Alosso. “The alarm system never notified us that there was a problem.”
According to Mr. Alosso, the backup generators automatically start when the plant monitoring system detects a problem with the flow of electricity. It is the generators that trigger a multiple redundant alarm system, not the plant system itself.
“There was enough capacity in our lines that we never knew there was a problem,” Mr. Alosso said. “For whatever reason the generator alarm setting was set at a voltage lower than 335 volts, so it didn’t sense that there was a problem.”
He said the wastewater plant staff was not at fault for any part of the problem, and that all duty and on-call personnel were where they were supposed to be. He praised the work of the four employees who responded to the emergency. Mr. Alosso directed their efforts by phone from his home, where he is recovering from an illness and under doctor’s orders to remain at rest.
The first sign of trouble came when sewage began bubbling out of a grate at the corner of Main Street and Dock Street. Wastewater also began to back up through the grease traps of the Atlantic kitchen, and soon began to fill the basement of the restaurant. Wastewater covered all but the uppermost storage shelves, but did not rise into the first floor.
The restaurant managers said there were few people in the restaurant shortly after 4 pm, when the backup began. “If this thing had to happen it happened at the right time,” said managing partner Jaimie Zambrana.
The Edgartown fire department and the health department responded to the scene, along with a private sewage pump-out truck, a trash truck, and private emergency restoration services.
“We’re going through a few stages of cleanup, and the health department approves us at every stage,” managing partner Eli Levy said. Mr. Levy could not estimate the damage caused by the sewage backup. “It’s the supplies and the loss of business,” he said. “This is our big season. It’s big damage, but I can’t give you a figure.”
The managers hope to have the Atlantic and the Boathouse Club open for business again tomorrow. “We have new inventory coming in on Friday,” Mr. Levy said. “Everything has to go through the approval of the health department, so we’re pretty safe from that end.”
Edgartown health agent Matt Poole said the cleanup effort is on track. He was at the restaurant through late Tuesday evening, and back to inspect Wednesday morning. He consulted with the food safety program at the state Department of Public Health to make sure the cleanup effort follows all safety regulations.
“They have to take it back to scratch,” Mr. Poole said. “All the shelving is going to need to come out. Obviously, all the food goes. They’ll have to get it back to empty space, clean it, sanitize it. It will have to be approved by us to begin the restoration, then they can start to rebuild it.”
What went wrong?
Mr. Alosso said the plant shutdown was unforeseeable. “There was nothing we could have done to avoid it,” Mr. Alosso said. “Things like this happen. Usually NSTAR is pretty good in letting us know they anticipate their grid is going to go down, and give us the heads up so we can switch over to generator power. We didn’t receive any such calls last night.”
Mr. Durand said the company’s focus was on fixing the problem as quickly as possible. He could not pinpoint the reason for the equipment failure, but said it was likely related to demand, spurred by higher than normal use of air conditioning. Mr. Durand said usage figures for individual areas were not available, but across the entire NSTAR system, demand peaked on Tuesday at just over 4,800 megawatts. NSTAR serves 1.1 million electricity customers in 81 communities. The record for peak demand happened in 2006, at 4,950 megawatts.
“There was a significant demand for electricity,” Mr. Durand said. “We did not approach our all-time system peak, but we were on the way.” He said the voltage dip went unnoticed by most NSTAR customers. He said some may have noticed lights dimming, but most home electrical appliances are designed to compensate for short voltage drops.
Mr. Alosso has called representatives of the treatment plant equipment manufacturers to see whether an adjustment in the alarm system is necessary. “The reason it’s the way it is, is because normally we have fluctuations where it might dip down to 335 volts, but then it will jump back up to 480. We don’t want the generator kicking on every single time.”
On July 4, the sewage treatment plant set a record for the number of gallons of wastewater processed, at 449,000 gallons. Though he had not yet seen the usage figures, Mr. Alosso estimated the plant processed about 400,000 gallons on Tuesday.
Mr. Alosso expects the Atlantic and the Boathouse Club to seek reimbursement from the town. “They will probably make a claim to the town for damages, while the town will turn around to the insurance company, and make a claim against NSTAR for damages.”
The two establishments opened in 2008, on the site of the former Navigator restaurant. The first floor waterfront restaurant and bar is open to the public, while the Boathouse Club, on the second floor is private and affiliated with the Field Club, a luxury recreation community in Katama. Reconstruction of the building included a complicated excavation for a storage basement, within feet of Edgartown harbor. The building is the lowest point in the town sewer system. No other restaurant in the area has a basement, and none experienced sewage backups. Most, however, realized a sudden spike in business, as restaurant patrons looked for alternatives to the Atlantic and the Boathouse Club, which closed just before the dinner hour.