A museum, public plaza, hotel, and mixed-use development are sprouting around the East Bay area of the Port of Olympia, Wash. The heart of the new 14-acre waterfront redevelopment will be a public plaza to attract residents and tourists to the downtown area focused around, of all things, the Budd Inlet Treatment Plant.

“A treatment facility has become a centerpiece to a business district,” says operations supervisor Ben McConkey. “It’s a fascinating experience.”

The plant has been there for years, operated by the LOTT Clean Water Alliance, a partnership between the cities of Lacey, Olympia, and Tumwater along with Thurston County. LOTT provides wastewater and reclaimed water service for the region, including the main sewer lines, pump stations, reclaimed water plants and recharge basins.

LOTT’s new $13.5 million Regional Services Center was recently added to the south end of the treatment plant. Expected to achieve Platinum certification under the U.S. Green Building Council’s Leadership in Energy and Environmental Design (LEED) rating system, the building is powered by a new cogeneration facility at the plant that burns digester gas to generate electricity and recaptures heat for digesters.

The heat is also used in the HVAC system at the plant, the services center, and a new children’s museum being built across the street.

Saving money, cutting emissions

The Jenbacher (GE Energy) reciprocating engine and related equipment for the cogeneration system went online in December 2009 at a cost of $2.4 million. Puget Sound Energy (PSE) provided 70 percent of the funding through a $1.7 million energy conservation grant. The plant is capable of modulating from about 50 percent power up to a peak capacity of 335 kW, generating about 200,000 kWh per month. “It really gives us a lot of flexibility without having to build a gas storage facility,” says McConkey.

The only storage is the floating covers on the anaerobic digesters. Those digesters, treating the waste activated sludge from about 10 mgd of influent, create about 125,000 cubic feet of methane-rich digester gas every day.

Cogeneration provides about 15 percent of the plant’s power and will save about $144,000 a year in direct electricity costs — a payback of two to four years. The rest of the plant’s power is purchased through the PSE Green Power Program at a cost of just over 7 cents per kWh. Other LOTT facilities can pay from 7.5 to nearly 9 cents.

The cogeneration system also reduces emissions equal to taking 306 cars off the road or planting 478 acres of trees. “We used to flare about 50 percent of our gas,” says McConkey. “We flare less than 5 percent now because we don’t have much excess.”

Multiple uses

The system feeds the in-plant substation, which also serves the new LOTT services center. “The Regional Services Center has about an 80 kW load during the day, and we’re producing anywhere from 250 to 335 kW,” says McConkey. “We power the entire services center with the cogen, and the excess goes to equipment in the treatment plant.” Under normal conditions, the center is expected to use no utility power.

The cogeneration system was designed by Trane (Ingersoll Rand) and HDR in partnership with LOTT and PSE through an energy performance contract with the Washington State Department of General Administration. The engine/generator was selected because it is expected to produce the most usable energy per pound of carbon dioxide in comparison to other alternatives.

About 5 to 10 percent of the effluent from the Budd Inlet plant is converted to reclaimed water. The center uses it for non-potable water needs, such as flushing toilets, feeding a 25,000-gallon pond surrounding the center, irrigating the grounds, and supplying a water fountain.

The rest goes to process and wash water at the treatment plant, irrigation at nearby parks, and dust control at the Port of Olympia marine terminal. “Future projects, such as irrigating the State Capital campus and a golf course, may get us to a point of expanding our production of reclaimed water,” adds McConkey.

Wetland ponds

LOTT’s 2 mgd Martin Way Reclaimed Water Plant, a satellite plant with filtration membranes from Siemens Water Technologies, feeds five constructed wetland ponds. “The water goes into one of eight gravity infiltration basins and eventually makes its way back to the groundwater,” says McConkey. That system was just honored with an international award from the WateReuse Association.

Because of its focus on renewable energy, Trane presented its Energy Efficiency Leader Award for sustainable energy and operational efficiency improvements to LOTT in May 2010. “We just finished a lighting retrofit done in conjunction with PSE using high-efficiency fluorescent lighting,” says McConkey.

An APG-Neuros aeration blower retrofit is underway. PSE will fund about half of the cost of the high-efficiency bump-foil air bearings blower, which is expected to save LOTT more than $84,000 per year in utility costs and further reduce emissions.

There are other environmental awards in LOTT’s collection, an indication of the organization’s commitment to the environmental responsibility and renewable energy.