USGS - science for a changing world

South Dakota Water Science Center

orange dotHome orange dotScience Topics orange dotOur Cooperators orange dotPublications/Videos orange dotGIS/Geospatial Resources orange dotNewsroom orange dotOutreach orange dotContact




USGS Water Science Centers are located in each state.

There is a USGS Water Science Center office in each State. Washington Oregon California Idaho Nevada Montana Wyoming Utah Colorado Arizona New Mexico North Dakota South Dakota Nebraska Kansas Oklahoma Texas Minnesota Iowa Missouri Arkansas Louisiana Wisconsin Illinois Mississippi Michigan Indiana Ohio Kentucky Tennessee Alabama Pennsylvania West Virginia Georgia Florida Caribbean Alaska Hawaii New York Vermont New Hampshire Maine Massachusetts South Carolina North Carolina Rhode Island Virginia Connecticut New Jersey Maryland-Delaware-D.C.

Occurrence of the Gasoline Oxygenate MTBE and BTEX Compounds in Urban Stormwater in the United States, 1991-95

Gregory C. Delzer, John S. Zogorski, Thomas J. Lopes, and Robin L. Bosshart

U.S. Geological Survey, 1608 Mountain View Road, Rapid City, South Dakota 57702, USA

Phone (605)-355-4560, Telecopier (605) 355-4523,

Methyl tert-butyl ether (MTBE) is a gasoline oxygenate. Oxygenates such as MTBE, when added to gasoline, increase the gasoline's oxygen level and decrease vehicular carbon monoxide emissions and ozone levels in the atmosphere. MTBE disperses rapidly in water, was the second most frequently detected volatile organic compound (VOC) in a study of shallow urban ground water, and is less biodegradable than common gasoline compounds, such as benzene, toluene, ethylbenzene, and total xylene (BTEX). Urban stormwater is a possible source of MTBE found in shallow ground water.

The U.S. Geological Survey (USGS) sampled stormwater in 16 cities and metropolitan areas that are required to obtain permits to discharge stormwater from their municipal storm-sewer system into surface water. Concentrations of 62 VOCs, including MTBE and BTEX compounds, were measured in 592 stormwater samples collected in these cities and metropolitan areas from 1991 through 1995. Concentration data for MTBE and BTEX compounds in stormwater were compiled and analyzed, and the findings are summarized in this report. This effort was part of an interagency assessment of the scientific basis and effectiveness of the Nation's oxygenated fuel program and was coordinated by the Office of Science and Technology Policy, Executive Office of the President.

MTBE was the seventh most frequently detected VOC in urban stormwater, following toluene, total xylene, chloroform, total trimethylbenzene, tetrachloroethene, and naphthalene. MTBE was detected in 6.9 percent (41 of 592) of stormwater samples collected. When detected, concentrations of MTBE ranged from 0.2 to 8.7 miicrograms per liter (ug/L), with a median of 1.5 ug/L. All detections of MTBE were less than the lower limit of the U.S. Environmental Protection Agency (EPA) draft lifetime health advisory (20 ug/L) for drinking water. Eighty-three percent of all detections of MTBE in stormwater were in samples collected during the October through March season of each year (1991-95), which corresponds with the expected seasonal use of oxygenated gasoline in areas where carbon monoxide exceeds established air-quality standards. The median concentration of MTBE and benzene for all samples was statistically different and higher in samples collected during the October through March season than samples collected during the April through September season. Sixty-six percent of all MTBE detections occurred with BTEX compounds, and a proportionate increase in concentrations was found when these compounds occurred together. The proportionate increase could indicate a common source of MTBE and BTEX for those samples. Toluene and total xylene were the most frequently detected BTEX compounds and the most frequently detected VOCs in these investigations. Detected concentrations of toluene and total xylene ranged from 0.2 to 6.6 ug/L and 0.2 to 15 ug/L with median concentrations of 0.3 and 0.4 ug/L, respectively.

Presented to:

1997, American Chemical Society Meeting, Symposium of Fuel Oxygenates, San Francisco, Calif., p. 374-377.


1996, U.S. Geological Survey Water-Resources Investigation Report, WRIR 96-4145, 1996, 6 p.

USGS Home Water Climate Change Core Science Ecosystems Energy and Minerals Env. Health Hazards

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Wednesday, 09-Jan-2013 10:13:57 EST