TRENTON, N.J. (AP) — New Jersey's Department of Environmental Protection is fighting an attempt by environmental groups to throw out a $225 million pollution settlement between the state and Exxon.

In a court filing, the groups contend then-Gov. Chris Christie, a Republican, settled in 2015 for "pennies on the dollar" over years of pollution at two refinery sites.

Earlier state estimates put damages at $8.9 billion.

An appeals court has already said the $225 million settlement was reasonable, and the environmental groups appealed. In a filing dated Thursday, the DEP urged the state Supreme Court not to hear the case.

The New Jersey Sierra Club and other groups had been hopeful new Democratic Gov. Phil Murphy's administration would take a different stance than Christie.