Arlington and Dallas will consider resolutions this week to end green-cement policies giving preference to manufacturers with the lowest emissions rate, as part of a proposed settlement of a lawsuit with cement manufacturer Ash Grove Texas LP.

While both cities say the proposed settlement would reduce nitrogen oxides by 10 per cent, environmentalists contend that the agreement would undercut efforts to force Ash Grove to close its three wet kilns in Midlothian, the last three left in Texas.

The remaining cement plants in Midlothian are dry-process kilns.

"The entire point of the original green cement policy was to encourage a single ’industry-best’ standard applicable to all kilns regardless of kiln type," said Jim Schermbeck, executive director of Downwinders at Risk, which has been fighting Midlothian plant emissions for more than two decades.

"This settlement does exactly the opposite, carving out four special categories, including one just for the last three wet kilns in Texas at Ash Grove," Schermbeck said. "That category allows Ash Grove to release two to three times as much NOx [nitrogen oxides] pollution as any other cement plant in North Texas."

Jacqueline Clark, an Ash Grove spokeswoman, said it was premature for the company, based in Kansas, to comment.