New plan brings clean air for Southwest families

April 18, 2012

Jason Bane                                                 
(720) 763-3721

Sharyn Stein                                                  
(202) 572-3396
PHOENIX (April 18, 2012) — The Arizona Corporation Commission (ACC) authorized a plan today that provides for a sustainable transition towards a cleaner energy supply for one of the largest sources of pollution in the country – the Four Corners Power Plant.

The ACC authorized Arizona Public Service Company (APS), Arizona’s largest investor-owned electric utility, to undertake a transaction that will enable retirement of three aging coal-fired units. Taken together, these units are one of the largest sources of air pollutions in the Southwest. These pollutants are linked to respiratory ailments and a host of other medical problems, and mar some of the most spectacular vistas in the West. The Four Corners Power Plant is currently the largest source of nitrogen oxide (NOx) pollution in the country, emitting about 39,000 tons of NOx each year.

“Families shouldn’t have to make a choice between clean air and affordable energy,” said David Berry, Chief of Policy Analysis for Western Resource Advocates. “This is a great example of how we can effectively manage the economic and environmental risks of fossil fuel power generation.”

Under the plan approved today, APS will acquire Southern California Edison’s share of the newer, more efficient units at the Four Corners Power Plant and will retire three older units at the plant by the end of 2013. Southern California Edison is expected to replace its Four Corners generation with renewable energy and natural gas fired power plants, while APS plans to add selective catalytic reduction pollution control equipment on Units 4 and 5 to reduce emissions of nitrogen oxides. By retiring the 560 megawatts of old, inefficient coal plants and adding pollution control equipment to Units 4 and 5, the plan will reduce carbon dioxide emissions by 19% to 34%, sulfur dioxide by about 24%, nitrogen oxides by about 88%, and mercury by about 61%, relative to 2009 emissions.  These reductions will bring significant environmental and health benefits to those residing in the Four Corners area.  

Today’s order also requires APS to evaluate additional coal plant retirements as part of a systematic review of the economic and environmental risks around its remaining coal fleet, as well as to examine the potential for coal-solar hybrid systems. The ACC decision allows APS to move ahead with an emission reduction plan developed by the company to comply with Clean Air Act requirements to protect visibility at national parks such as Grand Canyon and Mesa Verde.

“This is an important step forward towards improving air quality in the Four Corners area,” said Pamela Campos, attorney with the Environmental Defense Fund. “Today’s plan will reduce pollution, maintain low energy costs, and provide clean, healthy air to families across the Southwest.”

Western Resource Advocates and the Environmental Defense Fund played a significant role in the proceedings, providing testimony on the environmental, public health and economic benefits of the plan approved today.

Download this press release as a PDF file
Western Resource Advocates is a regional nonprofit conservation organization dedicated to protecting the West’s land, air, and water. Offices or staff are located in Boulder (CO), Phoenix and Tucson (AZ), Pocatello (ID), Santa Fe (NM), Carson City (NV) and Salt Lake City (UT). Visit
Environmental Defense Fund (, a leading national nonprofit organization, creates transformational solutions to the most serious environmental problems. EDF links science, economics, law and innovative private-sector partnerships. See;