The Colorado Oil and Gas Conservation Commission said it confirmed a combined 458 barrels of oil spilled from sites operated by Anadarko Petroleum. The regulator said oil from storage tanks left the sites in floodwaters.
"Though Anadarko deployed absorbent booms in the first case, the booms collected residual oil in standing water pooled around the tanks (not water feeding into the river)," it said in a statement Thursday.
Anadarko said in a statement it has 20 people working on the issue from an emergency response center in Denver and more than 100 other workers in the field.
"We can confirm that during this flood event there were no impacts to the environment due to our drilling or hydraulic fracturing activities," the company said.
Colorado regulators responded to reports circulating on social media sites that dirty water from hydraulic fracturing had contaminated floodwaters. The COGCC said most hydraulic fracturing fluids were stored in secured storage tanks or taken off site in northeastern Colorado, where flooding was heaviest.
Eight of the 10 spills confirmed by COGCC were considered minor, meaning there was no measurable volume of release.
"In the context of this historic event, these spills are not an unexpected part of many other sources of contamination associated with the flood," it said.