自20世纪70年代以来，随着铅含量的降低，汽油中加入了燃料氧化物，以增加燃料辛烷值。20世纪90年代中期，随着《清洁空气法》（CAA）修正案规定的重新配方气体（RFG）计划的实施，汽油中的含氟量显著增加。CAA要求在美国不符合一氧化碳和臭氧国家环境空气质量标准的地区使用含氧化合物。甲基叔丁基醚（MTBE）等燃料氧化物用于增加汽油中的氧含量和减少一氧化碳排放。因此，甲基叔丁基醚的产量稳步增长，在有机化学品中排名第四，1998年美国的产量为153亿升。尽管RFG项目改善了空气质量，但不幸的是，MTBE ingasoline的广泛使用导致地表水和地下水受到污染，其中许多是饮用水源。 1996年，加利福尼亚州是第一个发现饮用水源受到MTBE污染的州。华盛顿州和缅因州也记录了类似的污染，美国地质调查局（USGS）和美国环境保护局（EPA）也在全国范围内记录了类似的污染。监测通常表明，地下水中的MTBE污染比地表水更普遍，污染程度更高。MTBE污染可能来自各种点源和非点源。地下水尤其容易受到泄漏的地下燃料储罐和管道、填埋场、垃圾场和溢出物的MTBE污染。另一方面，由汽油发动机驱动的船舶是地表水MTBE污染的最大来源，其次是燃料储罐泄漏、溢出、雨水径流和大气沉积。 MTBE对饮用水机构构成了一个独特的挑战，因为它能够污染饮用水水源，并且一旦污染发生，它就无法清除。与汽油中的其他碳氢化合物成分不同，MTBE的物理和化学性质（在水中的溶解度高，对土壤的吸附性差），使其易于与地表水流和地下水混合和移动。这些特性通过自然衰减过程（挥发、吸附、光降解和生物降解）和饮用水机构常用的处理过程，阻碍了MTBE从水中的去除。依赖地下水作为饮用水来源的机构最容易受到伤害，因为MTBE污染在地下水中发生的频率更高、水平更高。 例如，当检测到MTBE水平高达6000亿分之一（ppb）时，圣莫尼卡市的七口水井几乎一半的供水停止使用。尽管使用地表饮用水源的机构受到MTBE污染的运营影响的风险较小，但它们可能面临着平衡水源保护与公共娱乐通道的挑战。加利福尼亚州奥克兰市东湾市政公用事业区在应对这一挑战方面的经验被用来说明解决这一问题的实际和成功的方法。包括6个参考文献、图表。

Fuel oxygenates have been added to gasoline since the 1970's to augment fuel octane aslead levels were reduced. Their inclusion in gasoline increased markedly in the mid-1990s in response to the reformulated gas (RFG) program mandated by amendments tothe Clean Air Act (CAA). The CAA mandated the use of oxygenates in areas of the U.S.that did not meet National Ambient Air Quality Standards for carbon monoxide andozone. Such fuel oxygenates as methyl tertiary-butyl ether (MTBE) are used to increasethe oxygen content of gasoline and to reduce carbon monoxide emissions. As a result,MTBE production has increased steadily, ranking fourth overall among organicchemicals, with 15.3 billion liters produced in the U.S. in 1998.Although the RFG program has improved air quality, the expanded use of MTBE ingasoline has, unfortunately, resulted in contamination of surface and groundwaters,many of which serve as sources of drinking water. In 1996, California was one of thefirst states to detect contamination of drinking water sources by MTBE. Similarcontamination has also been documented in Washington and Maine, and, on a nationalscale, by the U.S. Geological Survey (USGS) and U.S. Environmental ProtectionAgency (EPA). Monitoring generally indicates that MTBE contamination ofgroundwater is more prevalent and at higher levels than in surface water.MTBE contamination can occur from a variety of point and non-point sources. Groundwater is particularly vulnerable to MTBE contamination from leaking underground fuelstorage tanks and pipelines, and from landfill sites, dumps and spills. On the other hand,watercraft powered by gasoline engines is the greatest source of MTBE contamination ofsurface water, followed by leaking fuel storage tanks, spills, stormwater runoff andatmospheric deposition. MTBE poses a unique challenge to drinking water agencies because of its ability tocontaminate drinking water sources and its resistance to removal once contamination hasoccurred. Unlike other hydrocarbon constituents in gasoline, MTBE's physical andchemical properties (high solubility in water and poor adsorption to soils), allows it toeasily mix and move with surface and groundwater flow. These same properties impedethe removal of MTBE from water by natural attenuation processes (volatilization,sorption, photo- and bio-degradation) and by the treatment processes commonly used bydrinking water agencies. Agencies that rely on groundwater as sources of drinking water are most vulnerablebecause MTBE contamination occurs with greater frequency and at higher levels ingroundwater. For example, seven wells comprising almost half the water supply of theCity of Santa Monica were taken out of service when MTBE levels as high as 600 partsper billion (ppb) were detected. Although agencies using surface drinking water sourcesare less at risk to operational impacts from MTBE contamination, they may face thechallenge of balancing source water protection with public recreational access. Theexperience of the East Bay Municipal Utility District of Oakland, California, in addressing thischallenge is used to illustrate a practical and successful approach to this problem. Includes 6 references, figures.