BALTIMORE, MD (October 12, 2005) – ExxonMobil is being asked to expand the scope of the remedial work it has proposed for its now closed Upper Crossroads gas station, Maryland Department of the Environment (MDE) Secretary Kendl P. Philbrick announced this afternoon.

Since early 2004, MDE has been working with Harford County Health Department and ExxonMobil officials to fully investigate groundwater contamination caused by the widely used gasoline additive, methyl tertiary butyl ether, MTBE. MDE is convinced that the ExxonMobil station was responsible for at least part of the MTBE contamination present in the Upper Crossroads area. MTBE can become introduced into the environment, particularly water, from leaking underground and aboveground petroleum storage tanks.

“We encourage ExxonMobil to continue working with the department and local community to ensure the protection of Maryland’s citizens and groundwater in Fallston,” said Secretary Philbrick.

In response to the petroleum company’s proposed Corrective Action Plan submitted in March, MDE states:

• Reduction of the study area as requested by ExxonMobil is denied. MDE has determined that the study area will remain the same.

• Additional groundwater and soil vapor extraction wells must be installed in the station’s storage system footprint and to the north of the proposed extraction well field to ensure capture and remediation of residual hydrocarbons.

• MDE will require ExxonMobil to install a network of monitoring wells to monitor the progress of remediation activities and the fate and transport of area wide contamination.

• No later than November 28, 2005 ExxonMobil must submit a revised Corrective Action Plan to address MDE Oil Control Program’s comments for review and approval.

MTBE replaced lead as an octane enhancer in gasoline and helps the fuel burn more completely, reducing harmful tailpipe emissions from motor vehicles. Other sources of MTBE include atmospheric deposition, stormwater runoff, watercraft and residential usage of fuels. EPA reports MTBE has been widely found in ground and surface water across the country although its impact on human health is still unproven.

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