FACTSHEET: Cleaning Up Navajo Generating Station

Quick Facts about NGS:

Size: 2250 MW coal-fired power plant consisting of 3 units. This facility is the 8th largest in the nation and is the largest on the Colorado Plateau.

Age: Became operational between 1974 & 1976.

Location: It is located on the Navajo Nation just 12 miles from the Grand Canyon and near Page, Arizona.

Air Pollution: Among power plants, NGS is one of the top ten sources of nitrogen oxide emissions in the country. Over the last decade, this plant has emitted an annual average of 30,000 tons of nitrogen oxide; 4,200 tons of sulfur dioxide; 19 million tons of carbon dioxide; and 420 pounds of mercury.

Visibility: NGS degrades visibility at 11 protected national park and wilderness areas. Its pollution is unhealthy and masks scenic vistas in murky haze during more than 4 months each year at the most impacted national parks, including the Grand Canyon.

Owners: U.S. Bureau of Reclamation; Salt River Project; Los Angeles Department of Water and Power; Arizona Public Service Company; Nevada Power Company; and Tucson Electric Power Company (in order of ownership percent).

Threatened National Parks and Native Lands

Let Navajo & Hopi tribal members tell you how they’re impacted by this pollution by watching the video.

Cleaning up Pollution from NGS

The U.S. Environmental Protection Agency (EPA) is currently proposing ways to reduce nitrogen oxides that are emitted from the Navajo Generating Station (NGS). The nitrogen oxide pollution from this plant dirties the air, noticeably decreasing visibility, making it harder to see the region’s prized landscapes – and leading to serious human health issues for visitors and local residents, particularly those on Native land.   To learn more about these impacts, please check out “A Sacred Trust,” a telling 4 minute video of indigenous people sharing their experiences with coal plant pollution in the Four Corners region.

The Clean Air Act’s Regional Haze Program requires antiquated park-polluting plants like NGS to clean up.  The EPA proposes to require Selective Catalytic Reduction (SCR) to reduce 84% of the plant’s nitrogen oxide emissions. That’s good news for the people and parks of the region, but only if enforced within a reasonable timeframe.

Timing Is Key: Native Lands Deserve Clean Air on an Equal Timeframe

Protected Lands Near NGS. Created by Nathan Miller/NPCA

EPA’ has requested comments on several alternative proposals unfortunately opening the door for this plant to continue polluting for up to 32 more years. EPA suggests that this additional time would be acceptable because the plant is on Navajo land. That is not a valid excuse to pollute our parks and endanger health for a decade or more. At a minimum NGS should be cleaned up within five years – whether through pollution controls, or better yet, transitioning to clean energy alternatives.

One of the alternatives that EPA is taking comment on is a proposal by the power plant’s owners and their allies that results in more pollution in the next three decades than EPA’s original plan to install pollution control within 5 years. While NPCA values pollution control alternatives, we cannot support this plan because it would leave national parks and communities with avoidably poor air quality.     
EPA was correct in proposing the best emission controls for NGS. The largest share of the plant is owned by the federal government. The president himself in his second inaugural address said we must transition to cleaner energy and that failure to do so would betray our children and future generations. Why not start by transitioning the government’s own coal plant to clean energy?


EPA’s analysis shows that SCR will reduce nitrogen oxide emissions cost-effectively at $2,240 per ton of nitrogen oxide removed. These costs are comparable to, or lower than, the costs assumed by other like coal plants. EPA’s decisions have required control costs in the $2,000-$5,000/ton range, and have considered costs above $6,000/ton to be reasonable.

Electricity rates are expected to increase by less than 1 percent for customers of the Salt River Project, preserving NGS’s position as one of the lowest cost electricity generators in the Desert Southwest. While NGS supplies electricity for water pumping, adding pollution controls does not mean that water rate increases must mirror the cost of controls; in fact, if government is able to cover its share of costs, water rate increases to tribes and others would not occur as a result of reducing the plant’s air pollution.

Health and Visibility Impacts

Every year, NGS’s emissions contribute to numerous asthma attacks and related hospital visits, along with heart attacks, respiratory problems, and premature death. Emissions from NGS’s smokestacks are associated with lost worker productivity and restricted physical activity throughout the region. EPA’s proposal would decrease these health impacts, and clear up the view of the region’s tourist-attracting national parks and wilderness areas as well.

The addition of SCR would more than double the visibility benefits realized from the recently added combustion controls at NGS, which have decreased its emissions moderately. EPA notes that SCR’s benefits would be “noticeable by most observers” visiting impacted landmarks like the Grand Canyon and Mesa Verde.   

Economic Impacts

Arizona receives $5 billion in revenue from resident and visitor recreation such as hiking, biking and camping. In 2011, more than 4 million people visited the Grand Canyon, which is just 12 miles from NGS. Good air quality is essential to sustaining and growing the vital recreation economy. According to the National Park Service, the national parks in the Four Corners region affected by NGS’s pollution annually generate a combined total of $1.08 billion in spending. Health care costs associated with NGS’s emissions, on the other hand, come at a cost to our bodies—and economy—of more than $128 million each year. 


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