CASPER, Wyo. (AP) — A group that represents Wyoming landowners is prodding state regulators to address future cleanup of ponds containing wastewater from older oil and gas operations.

The Powder River Basin Resource Council worries cleanup of the ponds could fall through the regulatory cracks.

Built in the early 1980s, the ponds were grandfathered in before a decades-old rule required companies to post money, or bonds, guaranteeing their reclamation.

The state Department of Environmental Quality is considering whether it should require companies to procure bonds for the old wastewater ponds, how it would go about that and how much the cleanup could cost operators.

Companies, for their part, say they do and will continue to comply with state rules.