2012/4/19 日本経済新聞

米、15年から排出規制　天然ガス開発時の大気汚染物質

　米環境保護局（ＥＰＡ）は18日、天然ガスや原油の掘削時に出る大気汚染物質の排出規制を2015年１月から完全施行すると発表した。新たな設備投資負担増などへの反対から最終決定が見送られていたが、環境対策を重視するオバマ政権の意向に沿い、一定の移行期間を経て導入を目指す。

「シェールガス」念頭に

　ベンゼンやトルエンをはじめ、天然ガスや原油の掘削時に大気中に放出されると健康被害や悪臭のもとになる揮発性有機化合物の排出を大幅に抑えるのが狙い。新たなエネルギー資源として注目される新型天然ガス「シェールガス」の開発では、水質管理に加え、開発現場での大気汚染への対応が問題となっていた。

　有害物質の除去には、井戸から漏れる際に燃焼処理する方式のほか、特殊な装置を使ってガスなどを捕捉し、同化合物などが発散されるのを大幅に減らす新たな技術（通称「グリーンコンプリーション」）がある。ＥＰＡの最終規制案によると、経過期間である15年までは２つの方式の併用を認めるが、完全施行後は燃焼処理を認めない。

　ＥＰＡ幹部は同日、新規制導入により、１万3000カ所に上るガス掘削井戸から排出され、有害なスモッグのもとになっているベンゼンなどの有機化合物のうち約95％を削減できると強調。工業分野から出されるメタンに関しては、およそ40％に相当する100万〜170万トンを減らすことができるとした。

　また、同幹部は「有機化合物の新規制は、天然ガスの産出を遅らせることなく導入できる」と説明。環境規制強化でガス掘削が難しくなるとする懸念に反論した。

April 18, 2012　AP

EPA rules slash air pollution allowed from natural gas wells

The Obama administration on Wednesday set the first-ever national standards to control air pollution from gas wells that are drilled using a method called hydraulic fracturing, or fracking, but not without making concessions to the oil and gas industry.

President Barack Obama in his State of the Union address strongly backed natural gas drilling as a clean energy source, and recently announced an executive order calling for coordination of federal regulation to ease burdens on producers. But he has come under criticism by the industry and Republicans for policies they say discourage energy development.

Top EPA officials said Wednesday that the new regulations would ensure pollution is controlled without slowing natural gas production. “By ensuring the capture of gases that were previously released to pollute our air and threaten our climate, these updated standards will protect our health, but also lead to more product for fuel suppliers to bring to market,” said EPA Administrator Lisa Jackson in a statement.

Much of the air pollution from fracked gas wells is vented when the well transitions from drilling to actual production, a three- to 10-day process which is referred to as “completion.” An earlier version of the rule limiting air pollution from gas wells would have required companies to install pollution-reducing equipment immediately after the rule was finalized.

Drillers now will be given more than two years to employ technology to reduce emissions of smog- and soot-forming pollutants during that stage. The Environmental Protection Agency will require drillers to burn off gas in the meantime, an alternative that can release smog-forming nitrogen oxides, but will still slash overall emissions.

Industry groups had pushed hard for the delay, saying the equipment to reduce pollution at the wellhead during completion was not readily available. About 25,000 wells a year are being fracked, a process where water, chemicals and sand are injected at high pressure underground to release trapped natural gas.

Besides the new standards for oil and gas wells, the EPA also on Wednesday updated existing rules for natural gas processing plants, storage tanks and transmission lines that will reduce amounts of cancer-causing air pollution, such as benzene, and also reduce methane — the main ingredient in natural gas, but also one of the most potent global warming gases.

There were other changes made since the EPA proposed the rule last July under a court order that stemmed from a lawsuit brought by environmental groups.

Wells drilled in low-pressure areas, such as coalbed methane reserves, would be exempt because they release less pollution during completion. And companies that choose to re-fracture wells using the pollution-reducing equipment prior to the January 2015 deadline would not be covered by other parts of the regulation.

Since companies could capture the natural gas and sell it, the EPA estimates that they would save about $11 million to $19 million a year starting in 2015.

The American Petroleum Institute, the main lobbying group for the oil and gas industry, said that much of the industry was already doing that. “We don’t need (the EPA) to come and tell our members we will save you money,” said Howard Feldman, the institute’s director of regulatory and scientific affairs. “Their business is natural gas. They get it that they are trying to capture as much gas as they can.”

The reaction from environmental groups was mixed on Wednesday, in large part to the two-year delay on requiring companies to perform so-called green completions. “This concession only promotes wasteful drilling,” said Jeremy Nichols of WildEarth Guardians, an advocacy groups which sued the EPA in 2009 to force regulation. But, he said, “these rules promise to safeguard our communities and keep the dirty process of drilling in check.”

Hydraulic fracturing is largely responsible for a natural gas drilling boom, but the technique has raised environmental concerns for its toll or air and water.

Last March, pollution from natural gas drilling in the Upper Green River Basin in western Wyoming triggered levels of ground-level ozone, the main ingredient in smog, worse than those recorded in Los Angeles, one of the smoggiest cities in the U.S.

In Dish, Texas, a rural town northwest of Dallas, the state’s environmental regulators detected levels of cancer-causing benzene, sometimes at levels dangerous to human health, likely coming from industry’s 60 drilling wells, gas production pads and rigs, a treating facility and compressor station.

At the same time, a state study in Pennsylvania of air quality near Marcellus Shale drilling sites in four counties found no emissions at levels that would threaten the health of nearby residents or workers.

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時事通信社　2012/04/03

米ＥＰＡ、フラッキング問題でまた一歩後退

米環境保護局（ＥＰＡ）はこのほど、テキサス州での頁岩層ガス（シェールガス）採掘で使用したフラッキング（水圧破砕）法が周辺の飲料水を汚染したとして、レンジ・リソーシズ社を相手取って起こしていた訴訟を取り下げた。フラッキング規制でＥＰＡがまた一歩後退した。
　ＥＰＡは先週末、レンジによる掘削によってテキサス州パーカー郡の飲料水が汚染されたとの主張を取り下げた。ＥＰＡは訴訟で、レンジが汚染井戸を修復させるよう要求していた。
　この１カ月間でフラッキングをめぐる規制でＥＰＡが後退したのはこれで３件目。その一つはワイオミング州パビリオン町近郊の井戸水汚染問題で、地下水にフラッキングで使われる化学品が含まれている公算が大きいとした当初のＥＰＡ報告草案に疑問が呈されて、ＥＰＡは州当局と改めて検査を行うとした。
　もう一つは、ペンシルベニア州ディモック町の１１世帯の飲料水検査で、近くでのフラッキング法による天然ガス採掘によって汚染されたとするべき証拠はないと発表したこと。この町では、キャボット・オイル・アンド・ガス社が採掘を始めたあと水が嫌な臭いがする、と住民が２００８年以降訴えている。ＥＰＡは６０世帯の水の検査をするとしており、残りの４９件については数週間中に結果を公表すると見られる。
　オバマ政権は、国内の豊富なシェールガスの生産を促進する一方で、環境保護団体などが水と大気を汚染していると批判している業界の規制も求められており、そのかじ取りは難しい。