LANSING, Mich. (AP) — Michigan Gov. Rick Snyder says he has “significant” long-term concerns after the company that operates twin oil pipelines in a Great Lakes waterway told state officials it found additional gaps in pipeline coating.

The Republican released a statement Monday after Enbridge Inc. issued an update on inspections and repairs along Line 5. The pipelines carry 23 million gallons (87 million liters) of oil and natural gas across northern Wisconsin and Michigan to refineries in Ontario each day.

Snyder says the company’s overview doesn’t indicate imminent danger for the Straits of Mackinac, but says the update is “deeply concerning.” He says he’s no longer satisfied with Enbridge’s operational and public information tactics.

Environmentalists want the 64-year-old pipelines closed. They say gaps in coating bolster their contention that the pipes are unsafe.