Editing Methyl tert-butyl ether (section)

==Regulation and litigation in the U.S.==
{{main|MTBE controversy}}

===Restrictions on MTBE manufacturing and use===
The [[Energy Policy Act of 2005]], as approved by the U.S. House of Representatives, did not include a provision for shielding MTBE manufacturers from [[water contamination]] lawsuits. This provision was first proposed in 2003 and had been thought by some to be a priority of [[Tom DeLay]] and Rep. [[Joe Barton]], then chairman of the Energy and Commerce Committee.<ref>[http://www.cnn.com/2005/POLITICS/04/21/energy.bill.mtbe.ap/ http://www.cnn.com/2005/POLITICS/04/21/energy.bill.mtbe.ap/] {{webarchive|url=https://web.archive.org/web/20050422043436/http://www.cnn.com/2005/POLITICS/04/21/energy.bill.mtbe.ap/ |date=2005-04-22 }}</ref> This bill did include a provision that gave MTBE makers, including some major [[oil industry|oil companies]], $2 billion in transition assistance while MTBE was phased out over the following nine years.<ref>{{Cite web | url=https://www.nbcnews.com/id/wbna7574562 |title = House approves $12 billion energy package|website = [[NBC News]]|date = 2005-04-22}}</ref> Due to opposition in the Senate,<ref>Charles Babington, House Again Passes GOP Energy Measures, Washington Post, June 16, 2004, at A4 (House passes Energy Bill, but Senate opponents of MTBE provision in House Bill have the votes to prevent its enactment).</ref> the conference report dropped all MTBE provisions. The final bill was signed into law by President [[George W. Bush]].<ref>United States. Energy Policy Act of 2005. {{uspl|109|58}}. Approved 2005-08-08.</ref> The lack of MTBE liability protection is resulting in a switchover to the use of ethanol as a gasoline additive.

===Cleanup costs and litigation===
MTBE removal from groundwater and [[soil contamination]] in the U.S. was estimated to cost from $1 [[1000000000 (number)|billion]]<ref>{{cite web |url=http://www.sigma.org/wr/reports/05/050523.html |title=MTBE Cleanup Estimates |author=<!--Not stated--> |date=2005-05-23 |website=SIGMA Weekly Report |publisher=Society of Independent Gasoline Marketers of America (SIGMA) |location=Fairfax, VA |archive-url=https://web.archive.org/web/20091009071418/http://www.sigma.org/wr/reports/05/050523.html |archive-date=2009-10-09}}</ref> to US$30 [[billion]],<ref>{{cite web |url=http://www.mtbe-eresource.com/liu.cfm |title=Long Island Utility Fighting to Defeat MTBE Safe Harbor |author=<!--Not stated--> |date=2004-03-16 |website=The MTBE e-Resource |publisher=Napoli Bern, LLP |location=New York, NY |archive-url=https://web.archive.org/web/20071020072714/http://www.mtbe-eresource.com/liu.cfm |archive-date=2007-10-20}}</ref> including removing the compound from aquifers and municipal water supplies and replacing leaky underground oil tanks. In one case, the cost to oil companies to clean up the MTBE in wells belonging to the city of [[Santa Monica, California]] was estimated to exceed $200 million.<ref>{{cite web |url=http://www.ens-newswire.com/ens/feb2005/2005-02-17-09.html |title=Oil Companies Pay Santa Monica MTBE Cleanup Costs |author=<!--Not stated--> |date=2005-02-17 |website=Environment News Service |publisher=Ecology Prime Media, Inc.}}</ref> In another case, [[New York City]] estimated a $250 million cost for cleanup of a single wellfield in the borough of [[Queens, New York|Queens]] in 2009.<ref>{{cite news| url=https://www.nytimes.com/2009/10/20/science/earth/20exxon.html |work=The New York Times |title=City Awarded $105 Million in Exxon Mobil Lawsuit |first=Mireya |last=Navarro |date=2009-10-20 | access-date=2010-05-12}}</ref> In 2013 a jury awarded the State of [[New Hampshire]] $236 million in damages in order to treat groundwater contaminated by MTBE.<ref>{{cite news |url=https://www.bloomberg.com/news/2013-04-09/exxon-mobile-is-found-neligent-in-new-hampshire-mtbe-use.html |work=Bloomberg |title=Exxon Mobil is Found Negligent in New Hampshire MTBE Use |first=Sarah |last=Earle |date=2013-04-09}}</ref>

Many lawsuits are still pending regarding MTBE contamination of public and private drinking water supplies.

===Drinking water regulations===
EPA first listed MTBE in 1998 as a candidate for development of a national [[Maximum Contaminant Level]] (MCL) standard in drinking water.<ref>EPA (1998-03-02). "Announcement of the Drinking Water Contaminant Candidate List." ''Federal Register'', {{usfr|63|10274}}</ref> The agency listed MTBE on its [[Safe Drinking Water Act#Unregulated contaminants|Contaminant Candidate List]] in 2022 but has not announced whether it will develop an MCL.<ref>EPA (2022-11-14). "Drinking Water Contaminant Candidate List 5―Final." ''Federal Register,'' {{USFR|87|68060}}</ref>
EPA uses toxicity data in developing MCLs for [[public water system]]s.<ref>{{cite web |url=https://www.epa.gov/dwregdev/how-epa-regulates-drinking-water-contaminants |title=How EPA Regulates Drinking Water Contaminants |author=<!--Not stated--> |date=2017-05-03 |publisher=EPA}}</ref>

California established a state-level MCL for MTBE, 13 micrograms per liter, in 2000.<ref>{{cite web |url=https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/MTBE.html |title=MTBE: Regulations and Drinking Water Monitoring Results |author=<!--Not stated--> |date=2014-08-04 |publisher=California State Water Resources Control Board |location=Sacramento, CA}}</ref>