NEWRY, Maine (AP) A decision by state regulators could make it difficult for the owners of a potentially rich lithium deposit in western Maine to extract the metal.

The owners of the Newry property asked the Maine Department of Environmental Protection to review the possibility of quarrying at the site. However, regulators decided earlier this month that the site would be viewed as a metallic mineral mine and not a quarry operation, said Maine mining coordinator Michael Clark on Monday.

Maine’s mineral mining laws are among the strictest mining laws in the country. The Freeman family, which owns the land, did not immediately return a phone call seeking comment.

New sources of lithium are in demand in the U.S. because the metal is critical to the development of rechargeable lithium-ion batteries used in electric and hybrid cars.