Comanche Generating Station Air Emissions

We reached a comprehensive, ground-breaking settlement agreement with many environmental and community organizations for our 2004 Colorado least-cost resource plan. This included the construction of a third unit at Comanche Generating Station in Pueblo, Colo., which officially went into service in July 2010.  

We believe the environmental settlement agreement resulted in valuable partnerships, environmental benefits and greater information sharing with our customers and the Pueblo community.

At our settlement agreement partners’ request, we are posting publicly reported Comanche Station air emissions information.

Comanche Unit 3 features state-of-the-art emission controls. We also installed additional emission controls on the two existing plant units. As a result, overall sulfur dioxide (SO2), nitrogen oxide (NOx) and mercury emissions at Comanche Station are lower than before the addition of Unit 3, even though electric generation at the entire facility more than doubled.

Specialized equipment located on our power plant stacks monitor power plant emissions. Continuous emissions monitors measure emissions of various substances found in flue gas before it leaves the stack.  This information is transferred to computers located at our facilities.  We use this data to monitor our operations continuously and to provide emissions information to federal and state governments to demonstrate our compliance with air regulations. 

We file quarterly Excess Emissions Reports with the Colorado Department of Public Health and Environment (CDPHE) for each power plant we operate in Colorado. The report describes periods of time when our generating facilities exceeded their emission limits, and the type, duration and cause of the emissions involved. Excess emissions can occur due to equipment problems or human error. The reports also note periods of time when emission monitors were unavailable to measure emissions due to monitor malfunctions, daily calibrations, routine maintenance and other required quality assurance checks.