By Selam Gebrekidan
NEW YORK (Reuters) - A leak in a natural gas liquids pipeline operated by Enterprise Products Partners spilled fuel into the Missouri River in Iowa, the company said on Monday.
The leak was on the Iowa side of Enterprise's Conway North line in Monona County and the company was recovering products from the shutdown pipeline, company spokesman Rick Rainey said.
This is the latest in a string of pipeline accidents in a year, many of which -- like the leaks on Enbridge's Inc two crude lines last summer and the 1,000 barrels of crude oil spilled from Exxon Mobil's Silvertip pipeline in July -- have raised serious environmental concerns.
Controllers detected a pressure drop early on Saturday in a 10-mile section of the 33,600-barrels-per-day pipeline between Decatur, Nebraska and Onawa, Iowa and immediately shut down the pipeline, Rainey said.
At the time of the leak, the pipeline was carrying 140,000 gallons (3,300 barrels/636,400 liters) of natural gasoline, a volatile liquid hydrocarbon derived from natural gas, but may have spilled fewer gallons, Rainey said.
The pipeline, part of Enterprise's mid-America segment, which has a 2,800-mile network in its northern tier, serves refineries, the petrochemical industry and propane markets in the Midwest region, Rainey added.
The Environmental Protection Agency said it has not responded to the leak since there has not been a visual verification as of Monday morning while the U.S. federal pipeline regulator sent an inspector to Burt County, Nebraska to monitor the leak.
"It is still possible that this was an equipment malfunction," said Chris Whitley with EPA's Region 7 office.
"Our main challenge is that natural gasoline is very difficult to detect even in large amounts," Whitley added.
Rainey said the leak may have sprung in an area that usually is on a dry riverbed but was underwater following severe flooding along the Missouri River this spring and summer.
Enterprise said it had not detected any natural gas liquids on the surface of the river when it conducted a flyover and that most of the products had dissipated quickly.
"So far, the company (Enterprise) has recovered 3,000 gallons of product from the pipeline, and has started a vacuum process looking to recover more mix of gasoline and water," said Kathy Lee, spokeswoman at the Iowa Department Of Natural Resources
The company will need approval from the Department of Transportation to restart the pipeline.
U.S. Midwest natural gasoline markets did not respond to the leak with a significant hike on Monday.
Natural gasoline at the Conway, Kansas, hub rose 3.00 cents a gallon to a bid/offer spread of $2.02-$2.0675 a gallon, brokers said. Natural gasoline at the Enterprise hub near Mont Belvieu, Texas, similarly rose 3.00 cents above Friday levels and traded at $2.27 a gallon.
"It's hard to distinguish today's natural gasoline price rise that is due to crude (rising) or the leak. We think the leak probably further supported prices after an initial jump from stronger crude," said a Texas-based LPG broker who requested anonymity.
Enterprise has not determined if the leak is related to scouring, damage to pipelines caused by debris and other floating matter carried by floods.
"The portion under the riverbed isn't where the problem is," Rainey told Reuters.
The area near the leaking pipeline was still prone to flooding, according to the Iowa Department of Resources.
Frequent floods in the Midwest region, particularly on the Missouri River basin, have inundated urban regions and farmlands in the Midwest, causing havoc on parts of the region.
The product in the pipeline at the time of the leak has complicated the recovery and spill detection process, according to regional regulators.
"It looks like we've lost a significant amount of product from the pipeline. Because we have not seen it floating on the river, it's possible that a lot of it has volatilized or evaporated," Kathy Lee, with the Iowa Department Of Natural Resources said.
(Additional reporting by Joshua Schneyer, Ayesha Rascoe and Robert Gibbons; Editing by Marguerita Choy)