Worth the Effort

With patience and a little investment, a Wyoming wastewater treatment plant saves energy, earns rebates and improves performance
Worth the Effort
More efficient 50 hp and 25 hp Aire-02 Triton models from Aeration Industries replaced several 75 hp and 40 hp aerator/mixers for surface aeration.

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Working through grant and energy rebate programs can get complicated and a bit frustrating. But it’s worth the effort, says Larry Pardee, director of Public Works in the Town of Jackson, Wyo.

“It was tough, but in the end we’re better for it,” he says. “It’s not just hard work. It’s staying committed to doing the right thing and having a long-term perspective.”

Pardee is pleased with 33 percent savings on the treatment plant’s electric bill. New energy-efficient equipment will cut the plant’s annual demand of 5.9 million kWh by about 1.95 million kWh and save about $85,000 a year.

The plant team’s tenacity led to funding most of the work with proceeds of various grants and rebates, giving the township a payback of about 15 months. Planning began in 2007, and most of the installations took place in spring and summer of 2011.

 

Aeration upgrades

Jackson lies in the Jackson Hole valley in western Wyoming, just south of Yellowstone National Park. The town received a state grant of $45,000 in 2007 for an energy audit to identify efficiency opportunities at the 5 mgd treatment plant, which serves the town’s 9,300 people and nearby subdivisions. The open-lagoon plant has 10 ponds and is the largest user of electricity in Teton County.

Five of the 10 lagoons use surface aeration, while the others have a fairly complex system of underwater pipes. “Oxygen is a friend of the microbiology going on in the lagoons,” says Pardee.

Effluent is UV-disinfected before release to the sensitive wetlands and ponds of the 960-acre Wyoming Game & Fish South Park feedgrounds elk refuge.

 

Better aeration

As part of the efficiency project, several 75 and 40 hp aerator/mixers for surface aeration were replaced with 50 hp and 25 hp Aire-02 Triton models from Aeration Industries. “Not only are they far more energy efficient, they have greater mixing capacity and inject higher volumes of oxygen,” Pardee says.

With the improved performance, the plant achieves the same results with 22 units rather than the 28 it used before. “We are wired to add four more,” adds Pardee. “If we do add them, the plant capacity would increase by 1 mgd.” He also looks forward to lower maintenance with the new aerators: “We were always out in boats on the lagoons working on the old ones.”

A new high-efficiency 150 hp variable-speed blower from HSI was also added for the underwater aeration system. That replaced two 250 hp fixed-speed blowers, still in good condition and used during times of higher flow. The new blower was much less expensive than adding variable-speed drives to the old blowers and will save the plant about $28,000 a year in electrical costs.”

An old SCADA system was also replaced with a new system from Rockwell Automation. “The old one was outdated, and there were some functions we couldn’t even use, so we were running some systems manually,” says Pardee. Next up is replacing the raw-water pumps – that will be done in about two years and should lead to even more energy rebates.

 

Varied funding

Cooperative efforts between the township, the county, the Lower Valley Energy cooperative, the Bonneville Power Administration, and the state resulted in $1.3 million in state grants to cover most of the $1.8 million cost of the efficiency projects. The town paid the balance but recouped most of that through energy rebates.

Lower Valley Energy issued an initial rebate of $457,700 in 2011, and another rebate of up to $85,000 is possible in 2012. Pardee estimates the town’s ultimate investment at $100,000, which would mean a payback of just one year and three months.

The plant also got $570,000 in federal stimulus funds from the American Recovery and Reinvestment Act to install a 165 kW fixed-array photovoltaic system at the treatment plant. The town’s share of that project was $280,000. “As long as the sun shines, that’s electricity I’m not buying at 5.5 cents a kilowatt-hour,” Pardee says.

 

The motivation

Jackson’s efficiency program was inspired by a large environmental conference hosted by a local ski resort in fall 2006. While the focus was the impact of global warming on the ski industry, the program left a big impression on those attending from Jackson, including Pardee and mayor Mark Barron.

“Energy efficiency and conservation are the wise way to go,” says Barron. “As a municipality, it is our obligation to learn how to spend taxpayer dollars much more efficiently.” In November 2006, Barron signed the U.S. Mayors Climate Protection Agreement. He is still the only Wyoming mayor to do so.

He then got the Teton County commissioners on board, and they worked with Lower Valley Energy to develop an energy strategy for the entire community. “By February 2007, we created a board, formed a committee, created work groups, and put together an action plan,” explains Pardee.

 

Organized approach

Called the “10x10” plan, it was a framework for cutting total fossil fuel energy consumption by 10 percent by the end of 2010, using 2006 as the baseline. “We had to absorb new energy users like new buses and buildings, so we really needed to cut energy use by about 18 percent,” says Pardee.

At the time, the Bonneville Power Administration was just beginning an effort to reduce total demand on its system, which was reaching its limits. BPA is the wholesaler of about 30 percent of the electricity in the northwest region of the U.S. To cut demand, it began providing funding to its retail providers, such as Lower Valley Energy, to encourage efficiency.

The state was also getting involved in energy planning. Barron was the only person outside the governor’s staff to sit on a panel that created a state energy performance contracting program to help communities get help to cut their energy use.

 

Need to reinvest

Meanwhile, the treatment plant needed upgrades. “We knew that a lot of our systems were at or beyond their life cycle,” says Pardee. “Beyond energy efficiency or saving the planet, we knew we had to reinvest in our plant. When the ‘10x10’ plan came about, we decided to take a deep breath and get ourselves aligned with the plan.”

Waiting up to two years for the various agencies to finalize their work caused some frustration, and even more came when the consulting firm Jackson selected refused to sign a performance contract and eventually pulled out of the state program.

While the town was a few months late on meeting the goal, Pardee and his staff were able to work through the complications. “It took painfully longer than expected, but it turned out better than any of us anticipated,” he says.

In his view, the “10x10” plan made the difference: “It educated us a lot on energy efficiency and really sharpened our focus to go deeper in ways we would not have thought of. It was very strategic, purposeful, and well thought out.”



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