Most States Have Found MTBE in Groundwater from Releases at Tank Sites; Fewer Have Found It in Their Drinking Water

Portions of 17 states and the District of Columbia currently use gasoline potentially containing the additive MTBE to limit air pollution (see figure 1). About half of the states also reported finding MTBE that they could not attribute to a leaking tank and suspected that it came from other sources, such as above-ground tanks used to store fuel. Some of the states that have identified MTBE contamination have also found that it reached drinking water sources. States Rely on Their Own Programs and Private Parties to Pay for Cleanups, but May Require Federal Funding to Accelerate Cleanups and Address Abandoned Tanks

States have relied primarily on their own funding programs and private parties to pay for cleanups, using the relatively small federal trust fund grants they receive for staff, program administration, and to a lesser extent, cleanups. State Funding Programs and Private Parties Have Paid for Most Cleanups

In creating the Underground Storage Tank program, the Congress expected tank owners and operators to take financial responsibility for cleaning up contamination from their tanks, correcting environmental damage, and compensating third parties for any injuries. However, a Maryland program official pointed out that the size of the annual federal grants to states has not kept pace with the salary and other costs they must cover for staff.
What GAO Found

To help limit air pollution, about a third of the states use gasoline that contains methyl tertiary butyl ether (MTBE), which burns cleaner. However, MTBE has migrated into wells and groundwater from leaking underground tanks used to store gasoline. The Environmental Protection Agency (EPA) has the responsibility through the Underground Storage Tank Program and works through the states to ensure that tanks do not leak and, if they do, that the contamination is cleaned up. To help states cover the program costs, Congress annually provides grants from a trust fund it created in 1986. Most of the 50 states have reported finding MTBE when they discover gasoline contamination in their tank sites and increasingly, in their groundwater, surface water, and drinking water. States have made progress in addressing the releases they have discovered, including MTBE contamination, but face a continuing and substantial cleanup workload. States typically depend on tank owners or operators to pay some of the cleanup costs and cover the remainder with their own funding programs and depend on relatively small federal trust fund grants to pay staff to oversee cleanups and administer their programs.