美國兩個環保團體，為了要施壓聯邦環保署，促請該機構整治國家公園和荒野保護區的廢氣排放，已對該機構提出告訴。
國家公園保育協會（National Parks Conservation Association）與環境保衛基金會（Environmental Defense Fund）21日於華府地方法院對環保署長強森（Stephen Johnson）提起訴訟。國家公園保育協會的清淨空氣與氣候計劃主任溫茲勒（Mark Wenzler）表示：「一般家庭對我們國家公園的印象不應該是被霾害汙染所籠罩，環保署需要嚴肅地看待自身的義務，確保天空的潔淨，讓所有美國民眾為了有個健康的假期而來到國家公園。」
環保團體希望，法院能下令環保署查核各州是否已提出符合《清淨空氣法》（Clean Air Act）的完整計畫，以預防並改善在國家公園及荒野保護區的空氣汙染。
《清淨空氣法》與環保署規章要求環保署於2008年6月17日前確認各州是否已呈遞霾害處理計畫，但環保團體指出該署未能完成該項查核，並表示僅有一小部分的州完成該計畫的提交。
絕大部分產生籠罩國家公園霾害的污染問題肇因於使用舊式污染控制設備的老舊發電廠與工廠。
國家公園保護協會在今年5月提出一份名為「模糊的視界」（Dark Horizon）的報告，評定出受到新燃煤發電廠污染威脅前十大國家公園。這些國家公園包含在維吉尼亞州的仙那度（Shenandoah）國家公園、田納西州與北卡羅萊納州的大煙山（Great Smoky Mountains）國家公園、肯塔基州的猛獁洞窟（Mammoth Cave）國家公園、科羅拉多州的維德台地（Mesa Verde）國家公園、內華達州的大盆地（Great Basin）國家公園、猶他州的頂礁（Capitol Reef）與錫安（Zion）國家公園，以及達柯塔州的風穴（Wind Cave）與惡地（Badlands）國家公園。除了這起訴訟案外，環保團體也呼籲布希政府停止削弱國家公園的潔淨空氣保護措施。
以國家公園方圓185英里為界，共有28座燃煤發電廠在這十座國家公園的大氣區域內。
無視局內科學家的反對，美國國家公園管理局（National Park Service）、加州國會議員沃克斯曼（Henry Waxman）與環保署提出了一項降低污染標準的條例，降低了燃煤電廠在國家公園附近興建的門檻。
此一條例列在《清淨空氣法》下的「新污染源審查條例」（new source revie）之中──依據該項條例，排放量增加的大型靜態空氣污染源，不論是新建或改建的廠房，皆需加裝最新的污染控制技術。
環保署對於這些條例的修訂，將會改變一家改裝過的工廠「是否有增加排放」的判定結果，以及是否要以此要求電廠安裝污染控制設備。
根據現今的條例，環保署將評估發電廠每年排放的汙染總量是否會增加。現在環保署提議只要每小時所排放的汙染量沒有增加，即便發電廠運轉時數增加且造成每年汙染總量增加也沒有關係。
國家公園保育協會警告，如果這項提案通過，國家公園上空的污染可能會變得更嚴重，國家公園內的野生生物與自然景觀，即使像大盆地這樣未受到空氣污染國家公園，也將受到傷害。
Two conservation groups are suing the U.S. Environmental Protection Agency to force the federal agency to clean up emissions that cloud the air over national parks and wilderness areas.
The National Parks Conservation Association and Environmental Defense Fund filed a lawsuit Tuesday against EPA Administrator Stephen Johnson in U.S. District Court for the District of Columbia.
"Family memories of our national parks shouldn't be clouded by polluted haze," said Mark Wenzler, director of clean air and climate programs at the National Parks Conservation Association. "EPA needs to take seriously its obligation to ensure clear skies for all Americans who seek out our national parks for healthy vacations."
The groups want the court to order the EPA to determine whether states have submitted complete plans required by the Clean Air Act to prevent and remedy haze air pollution in national parks and wilderness areas.
The Clean Air Act and EPA regulations require the EPA to determine by June 17, 2008 whether each state had submitted haze plans, but the groups allege that the federal environmental agency has failed to do so. They say only a small handful of states have submitted haze plans.
Much of the pollution problem that creates haze over national parks comes from old power plants and factories with outdated pollution controls.
In May, the National Parks Conservation Association issued a report entitled "Dark Horizons" identifying the 10 national parks most at risk from pollution from new coal-fired power plants.
They are Shenandoah National Park in Virginia; Great Smoky Mountains in Tennessee and North Carolina, Mammoth Cave in Kentucky, Theodore Roosevelt in North Dakota, Mesa Verde in Colorado, Great Basin in Nevada, and Capitol Reef and Zion national parks in Utah, as well as Wind Cave and Badlands national parks in South Dakota.
In addition to their lawsuit, the groups are calling on the Bush administration to halt its efforts to weaken clean air protections for national parks.
Twenty-eight coal-fired power plants are proposed within the air sheds of these 10 national parks, defined as a radius of 185 miles around each park.
Despite objections from its own scientists, the National Park Service, and Congressman Henry Waxman of California, the EPA has proposed a rule that weakens pollution standards and makes it easier to build new coal-fired power plants near national parks.
The change is in the new source review regulations under the Clean Air Act. Currently, these regulations require new and modified large stationary sources of air pollution that increase their emissions to install up-to-date pollution control technology.
EPA's revisions to these regulations would change the test for determining whether a power plant that is modified will increase its emissions of air pollutants and therefore whether it will be required to install pollution controls.
Under the current regulations, EPA evaluates whether the total amount of pollution emitted by the plant each year would increase.
The EPA is now proposing that even if the plant ran more hours and annual pollution increased, this would not matter as long as there was no increase in the amount of pollution emitted by the plant on an hourly basis.
National Parks Conservation Association warns that if this rule is finalized, the air over national parks would be more polluted, and wildlife and scenic views in national parks such as Great Basin, which is largely unaffected by air pollution, would be harmed.
