On more than one occasion, the taxpayers and sewer usersin Allenstown and Pembroke, N.H., have been able to keep money in their pockets because wastewater treatment plant superintendent Dana Clement helped develop a cost-effective solution to a problem.
In 2003, state authorities placed a moratorium on new connections to the Allenstown Wastewater Treatment Facility (formerly known as Suncook), which was at 100 percent of capacity. In addition, the plant, then 26 years old, had never operated as intended: The extended aeration plant was built with clarifiers that were too small for the design flow of 1.05 mgd.
“The biggest problem we had was in the springtime with inflow and infiltration,” Clement says. “We tried our best to take measures to assist the small clarifiers. It just wasn’t enough.” With upgrades needed, yet with no new connections to expand revenue and no desire from the community for increased sewer rates or taxes, the plant had to be entrepreneurial.
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“In 2005, we took a chance and started taking in septage,” Clement says. His team found ways to make it profitable to treat 100,000 gpd of septic tank waste, and the resulting revenue gave the community a stronger base for moving forward.
That’s just one example of how Clement has made a difference for his plant and community during 20 years on the job.
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Industry with promise
Wastewater treatment is not just about removing wastes from water — as with any good business, it’s about solving problems, generating revenue and maintaining assets. Clement likes the problem-solving aspect best.
A New Hampshire native, he began work life in a factory but found that position left little room for personal development. When cities began building treatment plants, he took notice: “I said, ‘Wow, here’s basically a new industry that I think would pose a lot of opportunity.’ So I went back to school and got a business degree and got into the field. Wastewater in this country was in its infancy. Even the technology had a long way to go at that point.”
Clement got his start in 1977 at the Hooksett (N.H.) Wastewater Treatment Plant. In 1981, he started his own construction business, which he managed until 1990, when the housing market took a nosedive. He then worked as an operator at the 32 mgd Lowell (Mass.) Regional Wastewater Utility until the superintendent position opened in Allenstown in 1992. “I’ve been here ever since,” says Clement.
When he took the job at Allenstown, it was a Grade II plant, and he had a New Hampshire Grade IV (highest) certification. The hiring authorities were looking beyond certification, seeking someone with business training or experience.
Clement definitely had the experience and wanted to be a manager. “It’s always been my ambition,” he says. “I really enjoy challenges. The biggest satisfaction I get is seeing results from solving problems, and the most effective way you can do that, in my mind, is if you have some control over how it is done. A manager has that ability.”
At Allenstown, Clement works with seven team members: chief operator Jeff Backman, operators Russell Smock and Richard Slager, mechanic Ernest Beauchesne, laborer David Herron, administrative assistant Andrea Martel, and office assistant Rebecca Marquis.
“I think the mindset of working a problem until a solution is found is everyone’s attitude here,” he says. “The operators are constantly coming to me with ‘I’ve found this problem,’ or ‘I’ve found that problem and I think I have an answer.’ They’re problem-solvers, and I think that’s the key — paying attention to detail and being determined to find a solution to a problem.”
The problems Clement has helped solve go well beyond equipment and process issues at the plant — they include issues fundamental to the business of running a wastewater operation.
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The Allenstown Sewer Commission, an elected board, appealed to voters in 2007 and 2008 for funds to upgrade the treatment plant and end the moratorium on new connections. The commission invested in a full plant design, but the price tag on the facility was too high for the voters, at $16 million. The populations of Allenstown and Pembroke are about 5,000 and 7,300; median incomes are around $57,000, and 12 percent of family incomes in Pembroke fall below the poverty level.
Three times a charm
“We went back to the drawing board and came up with a Plan B at one-tenth the cost of a full plant upgrade,” Clement says. The commission tapped the American Recovery and Reinvestment Act (federal stimulus funds) and septage revenue, each providing half the money needed ($1.62 million in 2009 and $360,000 in 2011) for new technology that would effectively increase capacity.
That technology, the BioMag process developed by Cambridge Water Technology (CWT [now Siemens]), uses a ballasted floc system that was untested in a full-scale municipal wastewater treatment application (see sidebar). By 2009, the commission and the voters seemed to have reached an understanding. Even without a facility design in hand, the authority won voters’ approval for the new plan.
The commission met the federal deadline of February 2010 for a signed construction contract, and the project started taking shape in April. About 10 months later, the BioMag equipment was installed in a new building.
However, Clement and his team had to manage conduit, piping and process tank work to create and expand an anoxic zone, an anaerobic zone, and the associated nitrate return pumps and mixers. They also changed the aeration system to gain control of each tank individually.
They removed all the old piping and coarse-bubble diffusers, and then installed new main air headers with fine-bubble tube diffusers (Environmental Dynamics International) and modulating valves (Asahi), controlled by the plant SCADA system based on inline dissolved oxygen monitors (InsiteIG) as well as ORP monitors in the selector zones.
On a limb
Municipal bodies typically do not embrace unproven technologies, but Allenstown did in this case, in part because its leaders saw little choice. “We did go out on a limb,” Clement says. “However, the presentation from Cambridge was convincing, and they had been successfully conducting pilot projects at various locations. They had operating data that we could look at and evaluate. At this point, the process is up and running successfully.”
Since the BioMag installation, the plant has seen several spring rains large enough to have caused I&I problems in the past. “But we sailed right through them this time,” Clement says. “I can sleep at night not worrying about putting something into the river.”
The BioMag process completed its first year in February 2012. As of late 2011, CWT was estimating that the plant had gained 300,000 gpd in capacity — about 30 percent — with the technology. Clement says that should accommodate the two communities for a number of years.
Clement credits the commission for taking the risk. “The community needs to be thankful to them,” he says. “It’s been a lot of hard work on the part of plant employees, because we’ve had to do a lot of these side projects ourselves.”
The upgraded Allenstown facility replaced the extended aeration process with the Modified Ludzack-Ettinger (MLE) process and chlorine disinfection. At the headworks, a Jones + Attwood (Ovivo) 6 mm fine screen removes large solids and is followed by Milltronics (Siemens) OCM III ultrasonic flow measurement and Dorr Oliver (Ovivo) cyclone degritters.
ABS submersible and Aqua-Aerobic floating mixers are used in the selector tanks. Three 125 hp Tuthill positive displacement blowers provide aeration. Gorman-Rupp T3 self-priming centrifugal pumps move the return activated sludge. The plant discharges treated wastewater to the Merrimack River.
While the MLE process can remove phosphorus, the plant is not yet required to do so. Its new NPDES permit may include limits of 7.2 mg/L phosphorus, 0.0625 mg/L copper, and 24 mg/L ammonia. “We also expect a reduction in BOD and TSS from our existing 30/30 permit,” Clement says.
Dealing with septage
Meanwhile, septage and the resultant revenue continued to roll in, but complaints about odors escalated when the septage business began. Clement and his team covered sludge and septage holding tanks and the dewatering area, where 90 percent of the odor originated, and installed odor-control systems. “We reduced the complaints from a high of probably 70 a year down to three,” Clement says.
“Quite a few people in this town were getting pretty fed up with the odors. And they may have tried to stop us from taking septage. Faced with losing our only source of profitable revenue, we had to do something.” The facility purchased aluminum covers at a cost of $300,000 for the sludge and septage holding tanks, using revenue from septage treatment. The team designed and built all the components for odor-neutralizing misting systems for the holding tank and dewatering areas. Other measures included installing underground drains for waste pumping, automating septage waste measurement, and purchasing an automatic sampler for deliveries.
With a hint of pride in his voice, Clement says the Allenstown facility takes in more septage — 19 million gallons last year — than any other facility in New Hampshire. Operators decant and dewater the septage and send the solids and process biosolids to landfill.
Facility leaders may look at solids reuse as they consider a power-generating program. A Tennessee Gas Pipeline Company line goes through the 4-acre plant property. “We’re looking at generating our own power needs from natural gas and using the waste heat energy to dehydrate our solids to a Class A biosolid,” Clement says.
“Yeah, I’m pretty excited about it. We should be able to generate our own power for half the cost of what we’re buying from the grid and dehydrate our biosolids from our current 30 to 35 percent solids to 99 percent solids. We could actually sell it.”
Tackling an upset
Generally, the plant runs smoothly and is in compliance with its permit. But in January 2008, a local business drained ammonia from a holding tank to a floor drain, ultimately disrupting operations at the treatment plant. The ammonia killed much of the biomass and led to discharge of untreated or under-treated wastewater. Clement and his team returned the process to normal in three days.
“As soon as we assessed the severity of the problem, we took measures to isolate the ammonia and contain the biomass,” he says. “Next, we nurtured a viable biomass for availability once we were able to go back online. After the bulk of the ammonia had passed through, we air-stripped as much ammonia as possible from the process tanks. Then we slowly brought the process back online.”
When not dealing with plant or business issues, Clement is active in the New England Water Environment Association and New Hampshire Water Pollution Control Association. In 2010, his NEWEA peers honored him with the William D. Hatfield award, citing his achievements in improving treatment and reducing operating costs.
In 2005, he designed a new SCADA system. “Everything has been done from scratch,” he says. “First, we identified and prioritized areas needing improved control. Next, we inventoried instrumentation and control equipment, wiring, and modifications of existing equipment and construction components.
“Once the equipment was installed, I wrote the code for the PLCs and created the graphic screens for the operator interface. The last part has been an evolving project, as we are constantly changing processes, adding and removing equipment, and improving our control loops.”
As in any business, Clement likes to see what other plants are doing. He also enjoys traveling and will mix the two when he can — but only when traveling alone. “I just can’t convince my wife,” he says. “It’s not one of her highlights.”
- Activated Sludge Systems (9)
- Modified Ludzack-Ettinger (3)
- MLE (3)
- Sulzer Pumps/ABS USA (13)
- Aqua-Aerobic Systems Inc. (23)
- Asahi/America (8)
- Environmental Dynamics International (5)
- Gorman-Rupp Company (15)
- Hach Company (60)
- Insite Instrumentation Group (3)
- Kaeser Compressors, Inc. (14)
- Ovivo (49)
- Rockwell Automation (35)
- Siemens Water Technologies Corp. (68)
- Tuthill Vacuum & Blower Systems (5)
- Fine-Bubble Diffusers (22)
- Modulating Valves (1)
- DO Monitors (1)
- Fine Screen (22)
- Degritting System (3)
- Mixers (22)
- Positive Displacement Blowers (5)
- Centrifugal Pump (8)
- Colorimeter (6)
- Compressors (3)