Boardman coal plantThere’s little disagreement that pollution from coal plants is bad: unsightly at best and toxic at worst. That’s why state regulators are trying to cut emissions from the two coal plants operating in Centralia, Washington and Boardman, Oregon. But the two states do have different expectations for how effectively the coal plants can curb their pollution.

Some (admittedly back-of-the-napkin) math reveals that—once the plants meet their final goals—Washington’s proposed agreement could allow its coal plant to release three times as much pollution as its counterpart in Oregon, even after adjusting for their size differences.

One of the most worrisome coal plant pollutants is mercury, a long-lived neurotoxin that poses particular dangers to developing brains. In children, it’s been linked to reduced attention spans, fine-motor function, language, drawing abilities and memory.In animal studies, mercury causes rats to swim abnormally and get lost in mazes. (To put that in perspective, a recent study found mercury exposure was just one of dozens of health risks from coal plant pollution, which contributes to four out of the five leading causes of mortality in the US.)

In 2007, the two coal plants in Washington and Oregon each released more than 10,000 tons of nitrogen oxide (NOx), which contributes to air pollution and smog. The Centralia plant has been deemed third worst of all coal plants blamed for degrading visibility at wilderness areas and national parks. The National Park Service estimates the plant created haze at more than a dozen locations.

Mount Rainier HazeBoth states are looking to cut mercury and NOx emissions from these big polluters. (We covered greenhouse gas emissions in an earlier post.) At the Boardman coal plant in northeastern Oregon,  the state is expecting a 90 percent reduction in mercury by 2012 and a greater than 80 percent reduction in NOx by 2018.

Washington regulators are working to finalize a proposed agreement with Centralia’s owner TransAlta Corp.  to reduce mercury pollution by at least 50 percent by 2012 and NOx by 20 percent over current allowable levels.

Though the reduction targets sound straightforward, it’s difficult to draw apples-to-apples comparisons because each plant starts with different pollution levels. Centralia has some pollution controls that Boardman lacks, which have already reduced mercury emissions there by 25 to 30 percent, according to the Washington Department of Ecology. The existing pollution-control equipment at Centralia also limits what kind of technology can be added to achieve further reductions. (As one agency spokesman put it: you can’t go to a hardware store and buy a kit to build a coal plant. They all have different setups that dictate what pollution is released, how much it can be reduced, and at what cost.)

Still, by the numbers, Oregon has set more aggressive pollution reduction goals for its coal-fired power plant than Washington has. Even adjusting for the different sizes of the plants by factoring in generating capacity, Centralia could be allowed to release three times as much mercury and NOx as Boardman once the plants meet their ultimate pollution reduction targets in 2012 and 2018. (With one important caveat: the following numbers assume the plants continue to operate and burn roughly the same amount of coal as they have in recent years, which may not be the case in the future.)

Coal mercury chart
Coal NOx chart

Those trends are no surprise to people like Don Shepherd, an air quality expert with the National Park Service who finds Washington’s approach to regulating coal pollution anemic compared to Oregon’s. “It is like night and day and its kind of a puzzle to me why the two states would behave so differently,” he said.

So let’s take a closer look:

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  • Mercury

    Centralia has been releasing between 400 and 500 pounds of mercury in recent years, compared to between 137 to 281 for Boardman. If the plants meet each state’s pollution-reduction goals, Centralia’s emissions might be reduced to somewhere around 225 pounds in 2012, while Boardman’s would be around 28 pounds in 2012. (Oregon rules allow for a two-year extension to meet that goal if necessary.)

    We also can’t forget that Centralia is a more powerful plant, capable of generating about two-and-a-half times more electricity than Boardman. (The actual power produced fluctuates from year to year.) To make a fair comparison, we need to look at how much pollution each plant would be releasing per megawatt of generating capacity in 2012. If each plant meets its pollution-reduction expectations, Boardman would be releasing about 5 pounds of mercury per 100 megawatts, while Centralia would be releasing 16.

    To help explain that difference, Washington regulators say Centralia has agreed to install the same state-of-art-technology that other coal plants expect will reduce mercury emissions by 90 percent. That’s a bar other states – including  Michigan, Minnesota, Illinois and Oregon – have recently adopted. But because of Centralia’s physical configuration and existing pollution controls, the Department of Ecology says the very same technology may only yield a 50 percent reduction in emissions there (or more if the pollution controls work better than expected.)

    Kids fishingSo how much does mercury pollution from a particular coal plant affect us? It’s tough to say. The most common pathway for exposure is through eating fish, which accumulate the toxin after it’s deposited in lakes or water bodies. Because mercury from coal plants and other sources can travel hundreds or thousands of miles and permeates the atmosphere in different forms, it’s hard to point to any single source. In Washington, though, a National Park Service study found an unexpectedly high slug of mercury in snow at Olympic National Park, and comparatively high levels at Mount Rainier. Many fish taken from “pristine” lakes in both parks had mercury levels high enough to pose a health risk to wildlife such as kingfishers and otters. Some individual fi
    sh were contaminated with so much mercury that they wouldn’t be considered safe for people to eat. The report concludes that while most of that mercury originates from as far away as China and Europe, the Centralia coal plant is also a likely contributor.


    States are under a federal mandate to reduce haze in national parks and wilderness areas, which is caused in part by nitrogen oxide. According to the Park Service, pollution from both the Centralia and Boardman coal plants is reducing visibility in more than a dozen protected wilderness areas in the Northwest: Alpine Lakes, Diamond Peak, Eagle Cap, Glacier Peak, Goat Rocks, Pasayten, Hells Canyon, Mt. Adams, Mt. Hood, Mt. Jefferson, Mt. Rainier, Mt. Washington, North Cascades, Strawberry Peak, Three Sisters and the Columbia River Gorge.

    When taking its smaller size into account, Boardman today is a much bigger NOx polluter than Centralia. It released about 18 tons of NOx per megawatt of generating capacity in 2007, compared to roughly 9 tons for Centralia. But because it has fewer existing pollution controls, the Oregon plant (whose majority owner is Portland General Electric) can more easily and cost-effectively install state-of-the art NOx reduction equipment. That’s how Boardman plans to reduce its NOx emissions by nearly 50 percent by 2015 and by more than 80 percent by 2018.

    By contrast, Washington’s agreement with Centralia proposes a 20 percent emissions cut from current allowable levels. But the plant has already met that target in recent years, since it stopped mining dirtier local coal and started importing coal from Wyoming’s Powder River Basin. In a nutshell, the state has agreed to let the plant try to satisfy federal regulators by acknowledging pollution cuts that have already occurred, and not to require any further NOx reductions until 2018.

    So looking a few years out, what would the two plants’ emissions look like under these scenarios? In 2015, Boardman would be releasing about 9.5 tons of NOx per megawatt of generating capacity, while Centralia could still release 9 tons. But by 2018, Boardman will have to reduce its emissions to 3 tons per megawatt, while Centralia could theoretically still be allowed to release 9 tons.

    But with all these numbers in the mix, here’s another one to consider: Zero. That’s how much pollution these coal plants would release if they were no longer necessary or cost-effective. Trying to make dirty energy sources cleaner with expensive new technology is a band-aid approach at best. (It remains to be seen whether Boardman’s owners will decide that spending more than $500 million on upgrades to meet Oregon’s new rules is a worthwhile investment.)

    The smarter solution lies in helping homes and businesses become more energy-efficient, so we don’t need the dirty power in the first place. States should encourage electricity providers to quickly transition to less polluting sources—whether natural gas or wind or geothermal energy—in a way that preserves and even creates jobs. Because the simplest way to prevent coal pollution is not to burn it in the first place.

    Notes on Sources

    The pollution reduction comparison between Centralia and Boardman coal plants comes from recent mercury emissions data supplied by the Washington Department of Ecology and the Oregon Department of Environmental Quality; 2007 NOx emissions data from the EPA’s Clean Air Markets database, and minimum pollution-reduction goals outlined in Washington’s proposed TransAlta agreement and Oregon’s mercury and haze rules. The NOx calcuation assumes 2007 is the base year for Oregon’s reductions, and that Centralia consumes the same amount of coal as it did in that year, with 104,000,000 mmBtu of heat input. The mercury calculation also assumes Boardman consumes the same amount of coal as in 2007, with 47,000,000 mmBtu of heat input. To account for the difference in the plant size, emissions were divided by the generating capacity of Centralia (1376 MW) and Boardman (585 MW).The comparison and emissions estimates would not be valid if one of the plants operates significantly below capacity.

    This is the second in a series of Sightline Daily posts on coal in the Northwest. Here’s the first: “A Lump of Coal in Your Outlet.”.

    Photo of Boardman coal plant courtesy of Flickr user Tom Turnbull, Photo of Mount Rainier Haze courtesy of Flickr user edgeplot and Photo of kids fishing courtesy of Flickr user Mr. OutdoorGuy all under a Creative Commons license.