8:13am

Tue June 24, 2014
Oil and Gas

Latest Oil Spill In Poudre Raises Questions About Sites Near Rivers

After a Noble Energy storage tank that spilled 178 barrels -- about 7,500 gallons -- of oil into the Poudre River was discovered June 20, questions arose about how vulnerable some oil and gas facilities are to flood damage.

The Colorado Oil and Gas Conservation Commission has estimated [.pdf] that "more than 5,900 oil and gas wells lie within 500 feet of a Colorado waterway that is substantial enough to be named."

That data comes from a COGCC report following the September 2013 floods in Northern Colorado. About 1,150 barrels of oil and condensate spilled during the floods, as well as 1,035 barrels of produced water.

While the oil and gas industry was able to remotely close off many wells during the September floods, tanks and other storage and production equipment were more vulnerable, with some toppling from floodwaters.

In the report on lessons learned from the floods, the COGCC recommended that "Tanks, tank batteries and production equipment should be located as far from waterways as possible and practical in individual circumstances. It also recommended that tanks be anchored and supported on compacted fill."

In this case, springtime flooding on the Poudre River undercut a bank where a storage tank was sitting. The tank dropped downward and damaged a valve, which then allowed the oil to spill into the river. A produced water vault near the site may have also have leaked waste water, Todd Hartman, spokesman for the COGCC, said in a statement.

Noble Energy shut the wells in on May 24, when flooding first occurred. They were unable to access the site at that time because of high water and damage to the access road. They discovered the spill June 20, when they were able to access the site.

Region 8 of the U.S. Environmental Protection Agency oversaw and coordinated response efforts by Noble Energy, making sure the tank was no longer leaking oil. After that had been determined, EPA handed over control to the COGCC, although it will continue to monitor cleanup progress, said Region 8 spokesman Rich Mylott.

"Our primary concern is that discharge to water. Once it's clear that a site is no longer discharging to water, that's typically the point at which we try to transition to state authorities."

Both Mylott and the COGCC said they did not believe any drinking water was affected by the spill.

The U.S. Geological Survey stream gauge for the Poudre River at Fort Collins, upstream of the spill, peaked May 31 at 5,570 cubic feet per second. During the September floods, the Poudre River also flooded the area around the well site. The peak flow for the Poudre River at Fort Collins during those floods, on Sept. 13, 2013, was 8,140 cubic feet per second.

The well site, located at the end of Country Road 23 southeast of Windsor, had recently passed a post-flood inspection on November 22, 2013. In that report, the berms are listed as being in "adequate" condition.

Noble Energy also removed oil from a second storage tank on the site that was undamaged. Crews are working to clean up spill damage. They applied a product known as "Petro Green" to enhance the degradation of any remaining hydrocarbons, and no animals were identified as being affected.