The federal agency that regulates pipeline safety flagged several problems with the Trans-Alaska Pipeline that it said could pose a risk “to public safety, property, or the environment,” according to the Wall Street Journal.

As we noted last month, a leak had been discovered on the pipeline along a segment that had been flagged for replacement in 2008 by the pipeline operator, the Alyeska Pipeline Service Company.

Earlier this month, Alyeska received a letter from regulators at the Pipeline and Hazardous Materials Safety Administration warning that the pipeline had “a history … of corrosion problems” and urging safety repairs and upgrades, according to the Journal. Reuters details more from the letter, which we've posted:

Probes as far back as 2008 found issues including internal corrosion that had thinned pipeline walls by up to 80 percent in some spots, the letter said. While some measures have been taken since to mitigate corrosion risks, closer monitoring is required, it added.

Among other areas of concern is TAPS' ability to withstand a prolonged shutdown during Alaska's frigid winter months, when the risk of ice plugs and wax deposits in the line could make operations hazardous, according to the letter.

The company was given 30 days to give a written response to the notice, but no deadline was set for compliance with the recommendations.

As we’ve noted, Alyeska is owned by BP—its largest single shareholder—as well as ConocoPhillips, Exxon Mobil, Unocal Pipeline and Koch Alaska Pipeline. In 2007, Alyeska representatives told the House Energy and Commerce committee that accelerated corrosion was not a threat to the integrity of the pipeline system, according to Rep. Edward Markey, a member of the committee.

The company told the Journal that it disagrees with some of regulators latest findings, but has begun addressing a few items mentioned in the letter and plans to “work through this process" with regulators.