LONGMONT, Colo. (AP) — Two environmental groups want to help defend Longmont’s oil and gas regulations, which are stricter than new rules passed by state regulators this week.

Earthworks and the Sierra Club said their lawyers filed a motion to intervene in the lawsuit on Thursday. Lawyer Eric Huber said they’re asking to become defendants in the case brought by Colorado regulators against Longmont.

The move comes three days after the Colorado Oil and Gas Conservation Commission approved rules generally requiring that new wells be 500 feet from homes and buildings. The Longmont Times-Call reports that the city’s regulations, passed in July, require fast-tracked wells to be at least 750 feet from occupied buildings.

An industry group, the Colorado Oil and Gas Association, has already been allowed to intervene in the lawsuit.

(© Copyright 2013 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)