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Sierra Pacific Industries logo.

Sierra Pacific Industries reduces ammonia releases, saves resources and money


Sierra Pacific Industries (SPI) was able to reduce ammonia emissions at its Aberdeen plant by 75 percent after installing real-time monitoring equipment.

The Company

SPI is a third-generation, family-owned forest products company based in Anderson, California. The firm owns or manages nearly 1.9 million acres of timberland in California and Washington, and they are the second-largest lumber producer in the United States.

Photo of Sierra Pacific facility.
SPI Aberdeen burns waste wood to create
steam, which in turn generates renewable
electricity for the plant and Grays Harbor
Public Utility District.

Wood Products and Renewable Power

SPI’s Aberdeen plant operates a saw mill, then burns the mill’s waste wood to produce steam that is used to generate electricity. Called "cogeneration," the process turns 80,000 pounds of biomass an hour into a steady 18 megawatts of renewable energy – enough to both operate the mill and provide power to the Grays Harbor Public Utility District.

Better Monitoring Improves Air Quality, Reduces Waste

Burning wood waste to generate electricity also produces nitrous oxide (NOx) emissions. To control NOx, SPI Aberdeen injects ammonia into the plant’s flue gases, which turns the NOx into benign nitrogen and water.

Injecting too much ammonia, however, allows unreacted ammonia to get into the air. Ammonia can be harmful if inhaled and reducing ammonia emissions protects air quality.

Although SPI Aberdeen’s ammonia emissions were always within permitted levels, the company saw the opportunity to reduce emissions and operate more efficiently. In 2010, SPI began installing equipment that allows workers to monitor and precisely adjust the amount of ammonia they inject into the boiler exhaust. SPI Aberdeen invested about $30,000 to install the new equipment and software.

With the ability to inject just enough ammonia to create the needed reaction, SPI Aberdeen’s ammonia emissions dropped by 75 percent from 2011 to 2013.

John Gardner, cogeneration superintendent for Sierra Pacific Industries' Aberdeen facility (center, pointing), shows Ecology's Hugh O'Neill (left, in white hat) the plant's ammonia monitoring system.

To consult with Ecology’s Pollution Prevention experts about how to reduce waste at your Washington business, contact your regional office.