Our commitment to air quality

Protecting Arizona's natural resources, from our vital water supplies to the air we breathe, is at the heart of SRP's mission. Delivering on that mission means producing energy in a safe, cost-effective and environmentally responsible manner.

We are continually exploring new approaches that effectively reduce our environmental impact and improve air quality:

  • We have made significant investments in pollution controls at all of our generation facilities.
  • About one-third of SRP retail energy sales are met with a mix of carbon-free sources including solar, wind, geothermal, biomass, hydropower and energy efficiency.
  • We encourage our employees to be responsible environmental stewards at work and home; 80% of SRP's fleet vehicles operate on alternative fuels, including electric, biodiesel and ethanol.
  • We are the first utility in the nation to establish comprehensive sustainability goals to the year 2035.
  • SRP has planted more than one million trees in Arizona forest areas destroyed by fires.
  • We educate area teachers and students about air quality issues and offer our customers opportunities to get involved in reducing air emissions.


SRP's power generating stations are equipped a wide range of air pollution control equipment to reduce emissions of regulated air pollutants. Our coal-fired units have state-of-the-art scrubbing technology to reduce sulfur dioxide (SO2) emissions and combustion controls to reduce nitrogen dioxide (NOx) emissions. Additional controls to further reduce nitrogen oxides are either in construction or in the planning stages.

Many of SRP's gas and oil units are also highly controlled for nitrogen oxides to assist with maintenance of air quality in the Phoenix metropolitan area. Clean-burning natural gas is the primary fuel in these units; low-sulfur fuel oil is available for emergency operating situations.

Emission reductions

A graph showing that emission levels in 2012 are a fraction of what they were in 1995. SRP's air quality compliance strategy focuses on technically sound and environmentally beneficial ways to meet the stringent emission requirements associated with power generation. Since 1995, customer demand for electricity has increased by approximately 60%. Yet during this period, we have invested more than $1 billion in emissions controls.

The result? We have significantly reduced SO2 and NOx emissions intensity from 1995 levels.

Among the steps SRP has taken are:

  • Investing more than $500 million to upgrade air pollution equipment at Coronado Generating Station. The upgrade project, referred to as the Coronado Emission Control Project (CECP), has included the addition of new wet flue gas desulfurization systems and low-NOx burner technology on both Units 1 and 2. In addition, SRP is currently installing selective catalytic reduction (SCR) for additional NOx reduction on Unit 2.
  • Working with our co-owners to invest more than $510 million to upgrade air pollution control equipment at Navajo Generating Station. This work included the addition of new wet flue gas desulfurization systems and low-NOx burner technology on all three units at the power plant.
  • Reducing the use of products that generate hazardous waste and have the potential to release toxic air emissions. Instead of using high VOC solvents, SRP uses detergent and high-pressure water to clean mechanical parts.
  • Reducing fugitive dust emissions during construction and maintenance activities in the Phoenix metropolitan area. Efforts include the constant operation of street sweepers during dry-up work on the canals, a maximum speed limit of 15 mph to control dust from SRP vehicles and using physical and chemical stabilization to control dust during long-term projects.


Air quality regulation and policy is dynamic and SRP is engaged in many forums to keep abreast of changes that affect our operations. We also work regularly with local, state, federal and tribal officials on air quality implementation and compliance issues. SRP is strongly committed to development of new technologies that have promise in furthering emissions reduction goals and has partnered for many years with Arizona State University, the Electric Power Research Institute and other institutions to support research and development activities.

Temporary power

SRP offers home developers the convenience, cost-savings and environmental benefits of temporary electric power over gas-powered generators during residential construction. The meter provides outlets for construction power without energizing the main power panel. When the homeowners are ready to move in, a permanent meter is easily installed.

Green Lights

The Green Lights Program is sponsored by the Department of Energy and encourages businesses to use energy efficient lights.

In six years, SRP surveyed 1.2 million square feet of floor space and changed out all older, inefficient lights for more energy efficient lights throughout all our facilities. We also installed automatic timers in meeting rooms and offices.

The upgrades we completed resulted in saving 6,400 megawatts of electricity and eliminating nine tons of sulfur dioxide and ten tons of nitrogen oxides.