CHEYENNE, Wyo. (AP) — Proposed rules for oil and gas drilling on federal lands nationwide continue to be delayed amid a legal challenge.

A federal judge in Wyoming has ordered the Interior Department to better document how it developed the rules. The documentation originally was due to be filed with the court no later than this Wednesday.

A recent extension to Aug. 28 means the rules now won't take effect until sometime in September at the soonest.

Four states and two petroleum industry groups are suing to contest the U.S. Bureau of Land Management rules. On June 23, U.S. District Judge Scott Skavdahl in Casper suspended the rules hours before they were supposed to take effect.

The contested rules would require oil and gas developers to report all chemicals pumped underground during hydraulic fracturing.