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National Drinking Water Database


National Drinking Water Database - Chemical Contaminants

MTBE


Status: Unregulated - EPA has not established a maximum legal limit in tapwater for this contaminant.

MTBE (methyl tert-butyl ether) is a fuel additive that had been used as an octane enhancer in unleaded gasoline; it contaminates groundwater due to spillage or leakage at gas stations, and has been banned or scheduled for phaseout in most states.

 
Detected
Found above
health guidelines
Found above
legal limit
States
25
14
-
Water utilities
936
35
-
People Served
12,046,819
695,876
-

MTBE Exposure by State

Water utilities in 25 states have reported detecting MTBE in treated tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies.

StateWater Suppliers with MTBE contaminationWater suppliers reporting MTBE above health-based limits
SystemsPopulationSystemsPopulation
Florida7490,1511307,076
California271,089,0325207,541
New Jersey1293,321,872287,454
New York126848,817634,305
Maryland43109,767219,900
Massachusetts1393,810,838713,913
Missouri1020,719111,500
Indiana10180,83824,238
Rhode Island18102,34913,500
Alabama6147,19213,450
Delaware25375,93031,932
Wisconsin42291,5932907
Maine2328,1281100
Virginia14457,119160
New Hampshire228419,41300
Illinois24223,30500
Arkansas1761,10500
Texas829,95900
Nebraska911,56800
New Mexico49,67600
Iowa77,56700
Vermont124,34400
Michigan62,80100
Ohio12,00000
Minnesota173600
Total93612,046,81935695,876

The Most Polluted Communities

936 water utilities reported detecting MTBE in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average MTBE level

RankSystem Population Served Positive test results of total reported tests Average Level
(Range)
1Browns Lake Mobile Home Ct
Burlington, WI
2255 of 524.78 ppb
(21.2 to 28.25 ppb)
2Manana Woods Mutual Water Co
Scotts Valley, CA
3504 of 420.25 ppb
(12 to 37 ppb)
3Meadows AT Cross River
Bedford Hills, NY
63010 of 2017.21 ppb
(0 to 54.47 ppb)
4Brettview Acres Water Co
Hopewell Junction, NY
9204 of 515.06 ppb
(0 to 43 ppb)
5Chestertown
Chestertown, MD
5,4007 of 713.73 ppb
(6.8 to 29.5 ppb)
6Roettgers Oil - Thiensville Mobil Mart
Thiensville, WI
521 of 113 ppb
(13 ppb)
7Volmer Country Living Center
Vassalboro, ME
361 of 112 ppb
(12 ppb)
8Rockport Water
Rockport, IN
2,5004 of 711.54 ppb
(0 to 46 ppb)
9Fairton Oaks M H Community
Bridgeton, NJ
2073 of 311.37 ppb
(10.4 to 12.7 ppb)
10Juniper Hill Apartments
Charlton, MA
955 of 511.12 ppb
(6.3 to 18 ppb)

Health Based Limits for MTBE

StandardDescriptionLevel
California Public Health GoalsDefined by the State of California Office of Environmental Health Hazard Assessment (OEHHA) as the level of contaminant that is allowed in drinking water. For acutely toxic substances, levels are set at which scientific evidence indicates that no known or anticipated adverse effects on health will occur, plus an adequate margin-of safety. PHGs for carcinogens or other substances which can cause chronic disease shall be based solely on health effects without regard to cost impacts and shall be set at levels which OEHHA has determined do not pose any significant risk to health.13 ppb

Testing Summary for MTBE

Are tests routinely required for MTBE by federal law?No
Water suppliers reporting tests for MTBE (2004-2009):18,719 of 47,576
Average testing rate for water supplier reporting tests (2004-2009):0.7 per year