Derek Franz

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March 14, 2012
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How a biomass plant works and details of the Gypsum plan

On Tuesday, Gypsum Town Council approved annexation, zoning and other agreements that prepare the way for a biomass power plant to be built next to the American Gypsum plant north of U.S. Highway 6.

Eagle Valley Clean Energy LLC is the entity behind the plan. EVCE includes some Eagle County residents and Dean Rostrom, who has been the primary spokesperson for the group, which is based in Provo, Utah.

A biomass plant burns biological material to produce electricity. That is most commonly done by heating water with the burning material to produce steam, which turns a turbine that produces electricity, a process referred to as direct combustion. Biomass plants are most prevalent along the Pacific coast and, assuming it is built, Gypsum's will be the first commercial grade biomass power plant of its kind in Colorado .

In terms of its carbon footprint, Rostrom said a biomass plant is considered carbon neutral because its fuel regrows as opposed to being mined like coal.

The Gypsum plant would burn wood, especially forest thinnings and waste, such as trees killed by pine beetles, agricultural waste and clean urban wood. The plant would not compete with logging for valuable wood.

Wood would be collected in a 50- to 75-mile haul radius from Gypsum with a focus on closer areas. About 1,200 acres of forest would be needed per year for collection.

"The plant will be a long-term, unique and reliable outlet for hazardous fuel reduction with strong support from federal, state and private forest managers," Rostrom said.

As much as possible, the wood fuel would be chipped at the collection site before being sent to the plant. There is an economic motivation to have the wood chipped to do so. "Otherwise we have to handle it twice," Rostrom said.

Approximately 11 to 14 trucks per weekday would haul the chips to the plant during business hours. The trucks would mostly be "enclosed, Wal-Mart style trucks" and not logging trucks, Rostrom said.

The wood would be stored in silos with a seasonal reserve pile stored uncovered on the property.

The plant would burn about 70,000 tons of bone-dry wood chips per year. Additionally, 100 to 200 acre feet of water per year would also be needed. One acre-foot of water serves the needs of about 21⁄2 families of four for one year.

"It's a good trade - water for 500 families traded for renewable electricity for about 10,000 homes," Rostrom said.

The water would be used for steam production and cooling purposes. It must be very clean and would undergo a treatment process at the plant prior to being used. The used water would discharge from the plant as steam or go back into the Eagle River or to the Gypsum Wastewater Treatment Plant. EVCE is awaiting a state permit for direct discharge into the river. About 100 acre feet per year would be discharged into the river or wastewater plant. Gypsum town staff estimate the water vapor plume (not hot enough to be considered "steam") would be about 10 to 15 percent of the size of the American Gypsum plant's vapor plume.

Most of the ash from the burning wood - 99.5 percent - would be filtered out of the air by "state of the art multiple-clone and electrostatic precipitator technology." What escapes would not be visible. The collected ash - about a dump-truck load every few days - would be sold as fertilizer or sent to the landfill.

Noise pollution from the biomass plant is expected to be minimal, especially with most of the wood chipping performed off site. Lights would be minimal and down-turned, representative of the fact that only a couple employees would be working at night.

Gypsum Town Manager Jeff Shroll and Town Planner Lana Gallegos recently toured woody biomass plants in Oregon.

"(Shroll) and I really wanted to see what the air, noise, lighting, and pollution type of impacts there may be with these types of operations and we felt they were pretty minimal," Gallegos said, noting that town staff worked extensively with the applicant to improve the appearance of the plant facilities and create some additional screening to mitigate ground operations.

More facts about the Eagle Valley Clean Energy LLC plans:

• The plant would produce 11.5 megawatts per year.

• A 20-year electricity sales agreement for 10 MW per year is in place with Holy Cross Energy.

• The remaining 1.5 MW produced by the plant would power the plant itself.

• The plant has a 30-year life expectancy, possibly 40 or more if it is maintained well.

• Eagle County is supportive of the proposal and there is a memo of understanding for the landfill to segregate clean wood waste for pick-up by EVCE, which would save the county approximately $15,000 per year in mulching costs.

• The plant would result in more than 100 jobs during construction, 60 to 70 of them local, and more than 40 skilled-worker jobs after construction.

• The projected cost of the power plant project is $46 million.

• If approved, construction would start this year and finish near the end of 2013.

• The facility would be staffed by 12 people earning "above-average family wages" and the remaining jobs would be related to fuel collection and preparation.

• EVCE is in a land purchase agreement with LaFarge North America for the 93-acre parcel where the plant would be built and LaFarge is retaining the mineral rights.

• The plant would require 16 acres.

• EVCE is interested in preserving more than 60 acres of riparian habitat on the property as public open space. A potential land deal and public-private partnership is being negotiated.

• The plant would be directly east of the American Gypsum plant and 1,000 feet north of U.S. 6.

• The plant would be about 33,000 square feet; for comparison, the American Gypsum plant is 345,000 square feet.

• It would be about 80 feet tall at its highest point.

• The plant's ground pad would be recessed 20 to 30 feet below the railroad grade along U.S. 6.

• Berms 6 to 10 feet high would be landscaped with mostly conifer trees to reduce the plant's visibility.

• Access to the facility would be from one of two points on U.S. 6, which is yet to be determined.

• The seasonal reserve pile of wood chips stored uncovered would be at the north end of the property, away from U.S. 6.

• Previously under county control, the entire property was zoned industrial; now that it is being annexed by Gypsum, the zoning will change to 16 acres of light industrial where the plant would be located and the remaining acreage would be "developing resource," subject to the town's control.

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The VailDaily Updated Mar 14, 2012 02:54PM Published Mar 14, 2012 02:52PM Copyright 2012 The VailDaily. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.