The Rahway Valley Sewerage Authority commissioners took a beating from the public when they approved a $170 million clean-water plant upgrade, finished in 2009. As it turned out, that up grade and expansion saved residents and the environment a great deal of grief when Superstorm Sandy came calling on Oct. 29, 2012.
The Rahway Valley plant team fought off the storm and operated through it without interruption and without releasing any untreated water, while neighboring plants were swamped by the tidal surge and discharged billions of gallons of raw (diluted) sewage.
All told, they ran the facility for 17 days solely on in-plant engine power, operating in “island mode,” disconnected from the electric grid. To Jim Meehan, executive director, and the operations team, it was another example of doing what it takes to fulfill the authority’s mission: To be “the best, most efficiently run sewerage authority, in full compliance with all regulations, in the State of New Jersey.”
In the past few years, the team has worked diligently to drive down costs. They reduced the annual operations budget by a million dollars, to $12 million, by trimming staff from 61 to 51 through position elimination and attrition, by renegotiating the electric power contract and by general belt-tightening. “It’s a sign of the times,” says Meehan. “That’s what the public demanded and that’s what we gave them.”
Start to finish
Meehan and staff are proud to operate one of New Jersey’s few tertiary treatment plants, with a 40 mgd design flow, 105 mgd peak flow and 30 mgd average daily flow, discharging to the Arthur Kill, which adjoins the Rahway River. “We want people to understand that for the price they pay, we’re putting out nearly drinking water,” Meehan says. “We’re actually cleaning the river every day we discharge into it.”
The original plant was built in 1938 and upgraded in 1978. The upgrade completed in 2009 was a complete process overhaul that took seven years. It included a new headworks facility with coarse and fine automated bar screens (Infilco Degremont) and aerated grit chambers (Walker Process Equipment).
A new primary clarifier was added (there are now four) and the existing primaries were upgraded (Siemens Water Technologies). Similarly, two new Hi-Tech secondary clarifiers (Kusters Water) were added (there are now six) and the existing secondaries were upgraded.
An aeration system upgrade replaced two old gas-engine-driven blowers with three 700 hp electric centrifugal blowers (Roots/GE), and replaced ceramic dome diffusers with fine-bubble membrane diffusers (Sanitaire).
Tertiary treatment was added in the form of six gravity sand filters (Infilco Degremont). A UV disinfection system (Wedeco) with 936 lamps replaced a sodium hypochlorite system. In addition, the waste and return activated sludge systems were updated with new piping, tanks and pumps. All new motors are premium-efficiency models with variable-frequency drives; all major equipment has soft start capability.
Five dry pit submersible pumps (Flygt, a Xylem brand), each rated for 27.5 mgd, lift the incoming wastewater into the process. While effluent normally leaves by gravity, four screw pumps (Lakeside Equipment Corp.) are needed to discharge the water during abnormally high tides.
Biosolids are anaerobically digested, dewatered to 23 to 25 percent solids in a centrifuge (two 180 gpm Centrisys Corporation units and one 300 gpm unit) and beneficially used as landfill cover. Biogas produced at 200,000 cubic feet per day fuels boilers that heat the digesters, other processes and plant buildings, saving roughly $400,000 per year on natural gas. Biogas can also fuel a cogeneration system that includes four 1.5 MW engine-generators (Caterpillar). A pair of 2 MW diesel engines (Mitsubishi) with Baldor (Generac) generators provide emergency power.
Bob Valent, plant superintendent, says the team’s general approach to the plant is to operate “in the most efficient, lowest-cost and most effective way possible. One of our big points of emphasis is to watch the cost of utilities.” That includes running the blowers judiciously — just enough to keep adequate dissolved oxygen levels in the aeration basins.
“We manually take DO levels in the tanks three times a week, and we adjust accordingly,” Valent says. “Our DO demand is relatively flat, and since we’re not doing biological nitrogen removal, we don’t require highly sophisticated DO control.” The staff also keeps a tight rein on lighting costs, helped by LED lighting as well as photocells and motion sensors that make sure lights are on only when needed.
In his executive director role, which he assumed in 2010, Meehan fosters a collaborative management. Key members of the leadership team, in addition to Valent (with 27 years of service to the authority), are Andy Sasso, operations supervisor (30 years); John Buonocore, staff engineer (four years); Joanne Grimes, office administrator and qualified purchasing agent (28 years); Dan Ward, maintenance manager (10 years); Tony Gencarelli, regulatory compliance manager and engineer (11 years); and Bob Safchinsky, maintenance supervisor (18 years).
“I grab this whole staff and bring them into most of our meetings,” says Meehan. “I encourage them to speak out. Especially if they think it’s something I don’t want to hear, I ask them to speak their mind. We really do have a true team approach.” Others directly involved in plant operations and maintenance are:
- Industrial and municipal monitoring: Edward Kochick, supervisor.
- Health and safety: Janice Teixeira, coordinator.
- Shift supervisors: Edward Faryna, Mahendra Surujnath, Darren Schippe and David Patrick.
- Operators: Arcangel Bosque, Don McCoy, Heraldo Privado, Sterling Payano, Christopher Brinker, Doug Reno, Patrick Kellaway, Paul Dymyd, Craig Bender, Kevin Tierney and Naim Franklin.
- Biosolids operators: Javier Baez, John Vantuh and Marlon Privado.
- Electricians: Robert Remite, Peter Mladenovic and Jack Desimone.
- Maintenance: Scott Mackin, Harry Dones, Jim Thor and Stephen Moreira.
- Utility workers: George Cheskowich, Thomas Watters, Marcos Melendez, William Higgins, Mario Pasqualicchio and Richard Guerra.
- Laboratory: Jean Manigold, manager; Thomas Macaluso, supervisor; Sarah Keysper, chemist/lead analyst; Riley Blake and William Yachera, analysts.
Up to the task
Never were the team’s collective skills and the new plant’s capabilities more important than when Sandy blew ashore in New Jersey.
One saving grace was a change made in the plant’s elevation during the 2009 upgrade. Valent observes, “The elevations in the plant had to be raised for hydraulic purposes. The whole front end of the plant was lifted in order to get the grit chambers to work correctly, and from there it was a cascading effect, to get the water to flow through the rest of the plant by gravity. About 40 percent of the outside perimeter was raised by 10 feet just by pushing the land up higher on the side of the plant that runs along the Rahway River.”
Meehan notes that the tidal surge from Sandy came within a foot of entering the plant processes and knocking out service: “That 10-foot raise in elevation during the upgrade is what saved us.” That and the upgraded wet-weather capacity, which allowed the plant to handle a peak flow rate of 125 mgd for 12 hours or so during the height of the storm.
“We didn’t have a lot of rain associated with the event,” says Valent. “It was more the effect of the tidal surge. The collection systems of the towns we serve were flooded, and they were pumping plenty of rain water. We have an emergency relief line in the plant, but unfortunately the level of the river rose higher than the weir gate on that line, and we took in river water for a substantial amount of time.
“On our permit we’re rated at a peak flow of 105 mgd, which means we have to run four of our main influent pumps. We normally reserve the fifth pump for use in case one of the others is out of service for repair. During Sandy, we turned that fifth pump on.”
Generators to the rescue
The ultimate weapon against the storm, though, was the backup generation equipment.
On Sunday, Oct. 28, knowing the 1.5 MW gas engines needed a boost from the utility grid to start up; the team activated two of them.
“We’ve had incidents in the past where during storm events, if we’re running in parallel with the utility, we get dirty power,” says Buonocore. “For example, we’re a three-phase plant, so if the utility loses one phase and we have to run on two, that can damage some of our equipment. We’re better off completely isolating ourselves from the utility and just operating on our own power.
“We started two of the cogen engines, synchronized them with the utility and ran in parallel for a few hours. Once they were stable, we got permission from Jim and Bob to open the breaker on the utility side. At that point we were operating in the true island mode. We went on that way for about three days. All during the peak of the storm, we were on our own engine power.”
A near disaster hit on Wednesday morning, after the storm had passed and flows had returned to near normal, but while the utility power was still out. A process air blower tripped offline, causing a power surge that triggered a protective device, shutting the gas engines down.
“Our diesel backup generators kicked in, and we ran that way for about 36 hours, until we had mechanical problems with the both of them,” recalls Buonocore. “On one engine, the cooling system developed a leak, and on the other a fan belt broke. We got it working again, but we were in trouble, with no power grid to go to.”
There was no capability in the system to use diesel power, in place of the utility, to restart the gas engines — but that’s where experience and teamwork paid off. “Dan Ward, John Buonocore and our three electricians [Desimone, Mladenovic, and Remite] got together and came up with a way to ‘fool’ the programmable logic controllers on the cogen system into using the diesel power to jump-start those engines,” says Meehan.
“We called it a modified black start. Dan came in and said, ‘Jim, we think we have a way to get the cogen back on. Do you trust us enough to try it?’ Bob and I looked at each other and said, ‘Yes, go ahead.’ They pulled it off. They got the cogen units going again. We stayed for two more weeks on island mode because the grid power, although it did come back on after five days, was still very dirty. It would have knocked us on and off, which could have damaged our equipment.”
The bottom line
By keeping the power on, the Rahway Valley team was able to treat its entire flow even at the highest peak. “Neighboring authorities were putting about half a billion gallons of untreated waste into the receiving waters daily until they got back online,” says Meehan. “We processed every gallon that came through here.”
The plant ran 55 mgd through primary, secondary and tertiary treatment. The balance was primary treated and blended with the fully treated flow; the entire amount went through UV disinfection before discharge. “The only permit violations we had were small fecal coliform excursions for a couple of days after the storm,” says Meehan.
Not content just to keep their own plant running, Rahway team members lent a hand to others. Rahway provided lab services for neighboring authorities’ lab technicians who were displaced, and for several weeks they did all permit-required sampling and testing for the Linden Roselle Sewerage Authority, whose lab was disabled. Rahway also accepted hundreds of truckloads of landfill leachate and industrial vegetable washing waste for the Passaic Valley Sewerage Commission after its facility was disabled.
Throughout the crisis, the Rahway team performed admirably. “We had people who didn’t go home for four or five days,” says Meehan. “They would grab a nap and go back to work again.” Operations, electricians, mechanics and utility workers stayed at it around the clock. Most employees had lost power at home, and many brought their frozen food to the plant. Valent and others cooked meals and kept everyone well fed.
The team proceeded with full support from the Board of Commissioners. They gave regular updates to Richard LoForte, then board chairman, and he and other commissioners checked in often.
Damage to the Rahway plant was minor: an air conditioning unit blown off the roof of the administration building, HVAC ducts damaged on top of the cogeneration building, and the roof blown off a small sampling shack. “That was the extent of our physical damage, less than $50,000,” says Meehan.
Once clear of the storm and recovery, the Rahway team went back to business as usual. Valent says, “We have no capital upgrades planned, but we’re going to continue finding ways to optimize efficiency and cut our budget. We will continue to optimize and streamline operations anywhere we can.”