Suez execs share action plan for odor remediation

Plant’s digester tank seen as culprit


For residents of Seaford and Wantagh, Cedar Creek Park is normally a place to run with their dogs, let their children blow off steam and enjoy the sea breezes. But since May, odors from the Wastewater Treatment Plant at the southern end of the park have kept many residents indoors and on the phone to the facility’s operator, Suez North America.

More than a dozen residents showed up at the plant on Nov. 21 for a presentation on the issue, at which Suez executives outlined the measures being undertaken to fix the problem and to ensure that it does not recur.

The odor can be detected as far away as Route 135, more than 2½ miles distant, according to Seaford resident Laura Isola. “I could tell I was getting close just by the smell,” she said.

The plant’s general manager, Alan Weland, led the evening’s discussion, along with Suez Communications Director Lauren Sternberg and Seaford Harbor Civic Association President Phillip Franco. The presentation began with an explanation of the complex process by which up to 72 million gallons of effluent is cleaned to roughly 95 percent purity each day. At the end of the process, 10 so-called digester tanks remove the last of the wastewater’s contaminants before it is pumped into the Atlantic.

The integrity of the digesters is maintained with a liquid seal. The tanks’ covers sit atop their contents, and the resulting vacuum is supposed to ensure that no odor escapes, Weland said.

According to Weland, two or three of the facility’s 12 digesters undergo maintenance each year, and each of the tanks is cleaned once every five years. The digesters are emptied, their interiors are cleaned and any necessary repairs are carried out. As an inevitable side effect of the maintenance, the seal is breached, releasing some odors into the atmosphere. During normal maintenance, the seal’s integrity is usually restored within a week.

Plant records of odor complaints since Suez took over its operation bear this pattern out. The company has received 68 odor complaints to date this year — the most since 2016, when there were 70 complaints during Suez’s first year of operation, as it began overhauling and upgrading the facility’s equipment. Last year the company received just 11 complaints, despite carrying out normal maintenance of the digesters.

Before Suez took over the plant from the county, odor complaints were common, with 83 in 2012 and 91 in 2013.

This year, Suez determined that the addition of two external scrubbers per digester would help minimize any maintenance-related release of odors, and guard against unintentional release during normal operations.

Until this year, maintenance was carried out by a third party, contracted by Nassau County before Suez took over operation most of the county’s wastewater facilities four years ago. That contract expired this spring.

Installation of the scrubbers was not included in the contract, however, and as the county negotiated the cost of installation, it was decided that it would be more cost-effective to include the scrubbers in a new contract to be negotiated by Suez.

The negotiations stalled last spring, just as tank No. 5 was emptied of its contents and the seal was breached in preparation for maintenance. But because the maintenance contract expired, the tank has been sitting without an effective seal since May. The tank’s cover is in place, but odors continue to escape.

They are most noticeable in the evening, when there are onshore winds, Franco said. Michael Curcio, who lives on Beech Street in Wantagh, near the entrance to the park, said he could smell the plant most evenings. “It really impacts the quality of life in the neighborhood,” he said. Like many residents, Curcio and Franco have acquired a high level of technical knowledge of the plant’s operations.

The odors have long been strongest in the area around Seaford Harbor Elementary School. In the past, the school had to restrict outdoor activities when the smell was particularly bad. So far this year, the odors have not caused any interruption of normal activities, Seaford schools spokeswoman Jessica Novins said.

Neither the plant nor the wastewater treatment system as a whole is a stranger to controversy. County Executive Laura Curran’s office found in September 2018 that a miscalculation of roughly $18.4 million in the system’s storm water tax levy resulted in some 450,000 residents being overcharged, while more than 300,000 were undercharged.

Curran said at the time that the error began in 2016, under the administration of former County Executive Ed Mangano. She added that the bills of the affected customers would be adjusted over the next five years.

Suez is not responsible for setting the system’s rates or for billing, Weland said. “The county pays us $60 million a year to operate and maintain the system,” he said. “The county handles the billing.”

Weland added that the villages of Freeport, Hempstead and Rockville Centre collect their own waste, and deliver it to Cedar Creek for cleaning and disposal. “I don’t know what the villages charge their customers for that,” he added.

Suez processes wastewater for everyone connected to the system south of the Long Island Expressway through a network of roughly 3,000 miles of pipes, according to Weland. The company also operates a wastewater treatment plant in the City of Glen Cove. “We serve about 1.2 million of Nassau County’s residents, out of a total population of about 1.36 million,” he said.

Besides the scrubbers, Suez has undertaken a number of other initiatives to monitor any potential breach in the system that could result in odors, including what it calls its NOSE (No Odors for Suez Environments) system. Many of the plant’s doors have sensors, and another series of solar-powered sensors were placed throughout the facility, in the park outside the plant’s perimeter and at sites in the surrounding community. Currently, some of them are placed to track odors from onshore winds.

“I’m impressed that you guys have responded to our concerns so quickly,” Franco said.