Underscoring once again the dangers of America's unreliable fossil fuel infrastructure, a significant U.S. oil pipeline has been shut down after a leak was reported Monday morning.

Enterprise Products Partners said Monday it had shut its Seaway Crude Pipeline, a 400,000-barrel per day conduit that transports crude oil from Cushing, Oklahoma to Gulf coast refineries. The leak occurred Sunday night in an industrial area of Cushing. The company did not provide an estimate of the volume spilled, but said there was no danger to the public.

"Oil pipelines break, spill, and leak—it's not a question of if, it's a question of where and when."
—Anna Lee Rain YellowHammer, Standing Rock Sioux Tribe

"Seaway personnel continue to make progress in cleaning up the spill, substantially all of which has been contained in a retention pond at Enbridge's facility," the company said in a news release (pdf), explaining that the pipeline is a "50/50 joint venture" between Enterprise and Enbridge Inc. "Vacuum trucks are being used to recover the crude oil and return it to storage tanks on-site."

"The impacted segment of the legacy pipeline has a capacity of 50,000 barrels," the release added, "however the actual amount of crude oil released will be significantly less and won't be determined until recovery efforts are complete."

The incident comes after another pipeline rupture in Pennsylvania early on Friday, where 55,000 gallons of gasoline poured into the Susquehanna River, and about one month after a major gasoline pipeline run by Colonial Pipeline Co. had to halt pumping for a couple of weeks due to a spill in Alabama.

Meanwhile, UPI reports that "[t]he release from the Seaway pipeline is the second associated with the Cushing storage hub in less than a month. Plains All American Pipeline reported problems with infrastructure from Colorado City [Texas] to Cushing earlier this month."

Environmentalists, Indigenous people, and energy companies are in the midst of a heated debate over pipeline safety. Water protectors and their allies along the proposed route of the Dakota Access Pipeline (DAPL) have been saying for months that the project threatens their right to safe drinking water.

"Oil pipelines break, spill, and leak—it's not a question of if, it's a question of where and when," 13-year-old Anna Lee Rain YellowHammer, a member of the Standing Rock Sioux Tribe, wrote in a recent appeal.

"With such a high chance that this pipeline will leak," she wrote of the Enbridge-backed DAPL, "I can only guess that the oil industry keeps pushing for it because it doesn't care about our health and safety. The industry seems to think our lives are more expendable than others'."

Indeed, referring to the Cushing leak, one observer tweeted on Monday: "That's why we're screaming #NoDAPL! They always break!"