ANCHORAGE, Alaska (AP) — Officials in Alaska are responding to a pipeline leak on the Point Thomson gas field that resulted in a release of a still-unknown amount of liquid natural gas condensate.

The state Department of Environmental Conservation in an initial incident report said the operator, Harvest Alaska LLC, indicated the maximum amount that could have leaked is around 11,550 gallons, or 275 barrels. Harvest Alaska is a subsidiary of Harvest Midstream, which is an affiliate of Hilcorp Energy.

The state agency’s on-scene coordinator directed questions to Harvest Alaska spokesperson Justin Furnace, who released a statement from Andrew Limmer, regional vice president of Harvest Alaska. Limmer said the leak was discovered Saturday evening, and the company took “immediate action by shutting down the pipeline and promptly notified the relevant federal and state agencies.”

Limmer said cleanup operations have begun. The Point Thomson field produces natural gas liquids.

The cause of the leak is under investigation. The pipeline was immediately shut in and depressurized after the leak alarm notification, which prevented any remaining condensate from leaving the pipeline, according to the Department of Environmental Conservation.

The incident on the North Slope happened about 35 miles (56 kilometers) east of Prudhoe Bay.