A BP pipeline running along Sauls Creek in Bayfield was discovered ruptured last week, spilling coal-bed methane produced water into the creek and forcing the emergency construction of an earthen dam to prevent contamination downstream.
According to state reports, a 6-inch fiberglass gathering line was found leaking around 7 a.m. Dec. 13, about four miles west of Bayfield on National Forest Service land off County Road 527, also known as Forest Service Road 608.
The produced water - a byproduct of oil and gas extraction - traveled across a sagebrush/grass meadow and into Sauls Creek, an intermittent stream that flows into Beaver Creek, which meets the Los Pinos River a few miles south of Bayfield.
BP reported the creek was dry on Dec. 13, but the next day a state oil and gas inspector found Sauls Creek "contained runoff from snow melt." An early estimate shows the produced water traveled 2,300 feet along the channel bottom.
However, BP on Monday could not say how long the spill had been occurring, how much was released and what the contents of the product were.
The cause of the spill, too, remains unknown.
A Colorado Oil and Gas Conservation Commission representative wrote in an emailed response that more information will be included in supplemental reports and through ongoing water sampling.
After discovering the spill, BP crews immediately closed the line, shut down 17 wells and constructed a temporary earthen dam to contain the produced water from spilling further downstream.
A Dec. 15 follow up report indicated hydro-evacuation trucks were removing the standing water in the creek bed, recovering a total of 150 barrels - about 6,300 gallons - of produced water mixed with snowmelt.
The pipeline repair required that County Road 527 be restricted to one lane of traffic for four days last week as BP crews partially excavated the road, according to U.S. Forest Service spokeswoman Ann Bond.
Brett Clanton, a BP representative, did not address several of The Durango Herald's questions about the incident. He wrote the spill was isolated within two hours of discovery, the produced water contained no hydrocarbons and that no residents in the surrounding area were affected.
"With safety as our highest priority, we will continue to coordinate with relevant agencies to complete any further remediation efforts as warranted," Clanton wrote.
Produced water is a briny fluid captured in the rock of oil reservoirs that is extracted along with oil and gas. It is considered the largest toxic byproduct of extraction operations, and can contain salt, chemicals, residual oil and heavy metals, though the contents vary from well to well.
Although the chemical makeup of the substance released into Sauls Creek is unknown, a preliminary sampling showed the water contained 4,000 milligram per liter of total dissolved solids, compared to background values of less than 300 mg/L.
Total dissolved solids are a measure of all dissolved substances in water, and is generally used to gauge salinity. Salinity, in turn, can be an indicator for concentrations of chloride, sodium, magnesium, bicarbonate and sulfates, among others.
BP operates about 30 gas wells in the Sauls Creek area that produce coal-bed methane gas and produced water that is transmitted by pipeline to a processing facility in Bayfield.
BP likely faces "some kind of enforcement action due to impact on waters of the state," oil and gas commission spokesman Todd Hartman wrote in an email.
The company must continue further remediation efforts and water sampling. The temporary dam remains in place as these actions continue, Hartman said.
As of Dec. 19, there have been 19 reported spills in La Plata County in 2016 accounting for approximately 350 barrels of spilled substances, mostly produced water.
BP has accounted for 12 of those incidents, spilling about 165 barrels, according to COGCC data.
Two spills (including this recent one) did not have estimates for amounts leaked.