ANCHORAGE, Alaska (AP) — The first oil and gas production wells in federal Arctic waters have been approved by U.S. regulators.

The Bureau of Ocean Energy Management on Wednesday announced it issued a conditional permit for the Liberty Project, a proposal by a subsidiary of Houston-based Hilcorp for production wells on an artificial island in the Beaufort Sea.

The approval follows through on President Donald Trump’s promise of American energy dominance, said Interior Secretary Ryan Zinke.

Environmental groups oppose Arctic offshore drilling and have expressed concerns about the production record of Hilcorp Alaska LLC. State authorities in 2017 year fined the company $200,000 for violations at another production site.

The gravel island would be built in 19 feet (5.8 meters) of water about 5.6 miles (9 kilometers) off shore. The site is 15 miles (24 kilometers) east of Prudhoe Bay, North America’s largest oil field.

The base of the gravel island would cover 24 acres of ocean floor, about the size of 18 football fields, with sloped sides leading to a work surface of 9 acres, the size of nearly seven football fields.

To create the island, trucks would travel by ice road to a hole cut in sea ice and deposit 83,000 cubic yards (63,450 million cubic meters) of gravel. A wall would fend off ice, waves and wildlife, such as polar bears.

The surface would have room for 16 wells, including five to eight conventional production wells. At peak production, Hilcorp anticipates extracting 60,000 to 70,000 barrels per day for a total recovery of 80 million to 130 million barrels over 15 to 20 years.