An underground pipeline transporting saltwater from oil and gas drilling operations has leaked onto Indian land in North Dakota, but it appears the fluid has not impacted a nearby lake that serves as the reservation’s primary source for drinking water.

Crestwood Midstream Services Inc. told NGI’s Shale Daily the leak was discovered Tuesday in its water gathering system on the Fort Berthold Indian Reservation. The company said it believes the pipeline, which is owned by subsidiary Arrow Pipeline LLC, began leaking over the holiday weekend and estimates that approximately 24,000 barrels of water were released.

“The leak was quickly contained and the cleanup and remediation process is well underway,” the company said Thursday. “Importantly, based on sampling, visual inspection and other independent testing, there is no evidence that the spill has impacted Lake Sakakawea.

“Our highest priority, since containing the leak shortly after it was discovered, is to clean up the spill. We are taking all the precautionary measures necessary to ensure that this process will be complete and thorough, and we continue to work closely with the Three Affiliated Tribes and other appropriate federal and local authorities.”

Lake Sakakawea and Bear Den Bay provide drinking water to the reservation. The company said the ruptured pipeline was transporting saltwater to disposal wells.

Kris Roberts, spokesman for the North Dakota Department of Health (DOH), told NGI’s Shale Daily that the incident occurred within the borders of the Three Affiliated Tribes, a sovereign nation based at Fort Berthold. Roberts said the area is outside DOH jurisdiction.

“If it is shown that some of the contamination did get into Lake Sakakawea and Bear Den Bay, we may have some involvement at that point, but I’m not even entirely sure of that since that’s an area of the lake within their borders as well,” Roberts said Thursday.

Roberts said an on-scene coordinator from the U.S. Environmental Protection Agency arrived at the site Wednesday afternoon and was still there on Thursday. He added that the DOH was invited by the tribe to the scene on Tuesday.

“We saw dead grasses, dead vegetation and dying trees,” Roberts said, adding that it was unclear precisely when the rupture may have occurred. “That doesn’t happen overnight.”

Last fall, Crestwood purchased privately-held Arrow Midstream Holdings LLC for $750 million (see Shale Daily, Oct. 11, 2013). At that time, Arrow owned and operated a system of more than 460 miles of gathering pipelines on the Fort Berthold Reservation. That total included 150 miles of crude oil gathering lines, 160 miles of natural gas gathering lines and 150 miles of water gathering lines.

“When we acquired the Arrow gathering system in November 2013, the gathering system did not have a remote monitoring system in place,” Crestwood said. “The installation of a remote monitoring system (SCADA) has been a high priority, and having installed SCADA on the gas pipelines, we are expanding our SCADA capabilities to the crude and water pipelines.

“We believe the leak started over the holiday weekend. It was discovered through our regular monitoring process. We noticed a reduction in the volume of flow in our daily volume reports, so we started probing for possible reasons and uncovered the leak Tuesday morning.”