Natural gas is bubbling up from an underwater pipeline in Alaska’s Cook Inlet.


State regulators say the danger to public safety is minimal but the Coast Guard warned mariners to keep their distance and federal wildlife authorities expressed concern about possible harm to endangered beluga whales.


The leak four miles offshore is from an 8-inch line carrying processed natural gas from shore to power four drilling platforms.


The line belongs to Hilcorp Alaska, LLC.


“Hilcorp continues to work in cooperation with multiple State and Federal agencies to ensure a safe and effective response to the natural gas leak on a Cook Inlet fuel gas line,” the company wrote in a release sent Thursday.


A Hilcorp helicopter Feb. 7 spotted bubbles at the surface and reported the leak. Cook Inletkeeper, a watchdog group who says its mission is to protect the Cook Inlet watershed, posted a video (below) to YouTube shortly after the leak was discovered.


The company estimates the leak is emitting 210,000 to 310,000 cubic feet of gas per day. Crews have shut down “non-essential” equipment, according to Hilcorp, but the gas line must continue to keep positive pressure.


“If a minimum pressure is not maintained in the pipeline it could fill with water which would allow for the escape of residual crude oil, as this line was previously used as a crude oil pipeline,” the release states.


Floating ice is preventing divers from reaching the pipeline.


On Wednesday, Cook Inletkeeper’s executive director, Bob Shavelson, sent a certified letter to Jeff Hildebrand, Hilcorp chairman and CEO, stating their intent to sue over the leak. Hilcorp, according to Shavelson, is in violation of the Federal Water Pollution Control Act, also known as the Clean Water Act.