Arapahoe Station

Location: Just south of downtown Denver.

Plant Description: Arapahoe Station is a coal-fired, steam-electric generating station with two operating units.

Power Production Capabilities: 156 megawatts (MW): Unit 3 – 45 MW, and Unit 4 – 111 MW.

Fuel Source: Low-sulfur coal from the Powder River Basin in Wyoming.

Plant History: Arapahoe Station began operating in 1950 when Unit 1 went into service. It was followed by Units 2 and 3 in 1951, and Unit 4 in 1955. Units 1 and 2 (45 MW each) were retired Jan. 1, 2003, as part of Xcel Energy’s voluntary Denver Metro Emissions Reduction Plan.

Interesting Features: Located in an urban environment, Arapahoe Station is home to a variety of wildlife, including foxes and migrating birds. The plant also shares its property with several other industrial facilities, making the best use of the available land and electric facilities. Air Liquide, an organization specializing in providing industrial and medical gases, operates a liquid gas processing facility on site. Black Hills Colorado owns and operates two 39 MW natural-gas fired combustion turbines and one 42 MW steam turbine at the site. Xcel Energy purchases the electric output of the Black Hills’ facility.

Environmental Highlights: Air emissions are controlled on Arapahoe Station’s Units 3 and 4 by baghouses. Baghouses act like giant vacuum cleaners, removing particulate emissions from the flue gas by more than 99 percent. Unit 4 also has low-NOx burners that reduce nitrogen oxide emissions by about 40 percent and dry sorbent injection (DSI) that reduces sulfur dioxide by about 20 percent. DSI is also installed on Unit 3. In 2005, a closed loop ash dewatering system was added to the plant. By separating ash and water in tanks instead of ponds, water is recycled back into the system for reuse and ensures water entering the South Platte River meets stream standards.

Community Involvement: Arapahoe Station maintains a rest stop along the South Platte River Bike Trail and hosts a water station for bicycle commuters during the Denver Regional Council of Government’s annual Bike-to-Work Day. Plant employees are involved in beautification efforts, planting dozens of trees on plant property to support the City of Denver’s Tree by Tree - the Mile High Million tree planting initiative and The Park People’s Denver Digs Trees program. In addition, the plant collaborates with local emergency agencies and provides space for mutual training exercises.

Contact Information:

• Plant Information and Tour Requests — 1-800-895-4999
• Media Inquiries — 303-294-2300
• Black Hills Colorado — 847-465-3036