WASHINGTON -- Environmental groups on Monday announced a new ad campaign that highlights ExxonMobil's massive oil spill in Arkansas last month. The ads will be concentrated in the Washington, D.C., Metro's Foggy Bottom station, which is used by many State Department employees commuting to work, as the agency considers whether to approve the construction of the Keystone XL pipeline.

Oil Change International and Environmental Action teamed up with consumer watchdog organization SumOfUs.org to place the ads in Foggy Bottom on Monday. The ads will remain in the Metro station for a month as the State Department considers more than a million public comments submitted as part of its draft environmental review of the controversial Keystone XL oil pipeline, which would transport heavy crude from Canada to oil refineries along the Gulf Coast.

Keystone's developer would not be ExxonMobil, but the Calgary-based TransCanada.

"Exxon thought it could keep us from finding out what a tar sands spill looked like," said Kaytee Riek, campaign manager for SumOfUs.org in a statement. "Then over 2,000 people donated to make sure the photos that leaked out ended up exactly where it didn't want them: in front of State Department employees deciding this month to approve or reject the Keystone XL tar sands pipeline."

The ads feature photos of the Arkansas spill -- which on March 29 dumped an estimated 10,000 barrels of crude oil into residential streets -- and warn that the spill could be a preview of what's to come if the Keystone XL pipeline gets approved.

ExxonMobil did not immediately respond to a request for comment.

View the ads below:

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