State regulators on Friday confirmed more oil and gas spills totaling at least 3,200 gallons in Colorado's flooded South Platte River valley and estimated that two dozen storage tanks toppled in the past week's rush of water and debris.
But it is uncertain whether all will be — or can be — cleaned up.
Five spills in and along the river in Weld County currently are deemed "notable," according to a Colorado Oil and Gas Conservation Commission update Friday afternoon.
Two spills were confirmed Friday along the South Platte near Evans — 56 barrels, or about 2,400 gallons, from an Anadarko Petroleum Corp. site and 21 barrels, or about 800 gallons, from a Bayswater Exploration and Production facility.
Another new spill, reported by Anadarko, has not been measured, the commission update said.
The company PDC also reported production equipment largely washed away at an undetermined site. State authorities are working with PDC to determine the amount of material that was on site before flooding began on Sept. 12.
The latest spills were confirmed after aerial surveys, COGCC's update said. They bring the documented total amount released to more than 22,000 gallons.
Anadarko on Wednesday reported two spills in Weld County. About 125 barrels — or 5,225 gallons — spilled into the South Platte River near Milliken. A tank farm on the St. Vrain River released 323 barrels — or 13,500 gallons — near Platteville. Those two spills involved "condensate" — a mixture of oil and water.
"The COGCC is tracking these reports and full investigations will take place when access allows," state natural resources spokesman Todd Hartman said in the update that was released in response to media queries.
"Operators will be required to remediate environmental impacts where necessary," Hartman said.
Federal Environmental Protection Agency authorities also are assessing damage but are leaving it to COGCC to tally estimates of spilled material, EPA spokesman Matthew Allen said.
"We're primarily serving a role to assess and evaluate the sites that fall into our area of coverage, which are spills to the rivers," he said. "The state of Colorado and FEMA are the lead agencies on this response, and EPA will continue to work with them to coordinate any clean up and remediation efforts related to damages caused by the flooding as the water recedes and we're able to fully evaluate the situation."
Colorado law requires oil and gas equipment in the floodplain to be anchored to resist flotation.
Anadarko spokesman John Christiansen said Anadarko tank moorings held at the Milliken and Platteville
Anadarko placed two orange absorbent booms on surface water around one site near Milliken and used a vacuum truck to collect about 40 barrels' worth of the 165 barrels that had spilled, Christiansen said.
Floodwaters kept crews from reaching the tanks on the St. Vrain quickly, he said. "By the time we got there, they were empty."
Gov. John Hickenlooper, during a news conference Thursday, said the spills confirmed as of Wednesday "weren't excessively large."
"The several small spills we've had have been very small relative to the huge flow of water coming through," he said.
According to an oil and gas commission update Thursday, the state had six teams of inspectors and environmental-protection specialists looking for spills and damage and assessing environmental impact in the flood zone.
Anadarko, based in The Woodlands, Texas, is the second-largest operator in the oil-rich Denver-Julesburg Basin, which is centered in Weld County.
There 20,500 operating wells in Weld County, 321 wells in Boulder County, 97 wells in Broomfield County and 253 wells in Larimer County.
Larimer County emergency managers said Thursday they weren't aware of any spills. "We don't have the quantity of wells in Larimer County they do in Weld," sheriff's spokesman Nick Christensen said.
Anadarko said it has shut 250 tank batteries and 670 wells — about 10 percent of its operations — because of flooding.
The company has deployed about 150 people to check their sites, assess damage and make repairs.
The drilling rigs that the company could move have been transported to sites not affected by the flood. None of the sites where Anadarko is hydrofracturing — pumping large volumes of water, sand and trace chemicals into a well to crack rock and release oil and gas — are in flooded areas, Anadarko's Christiansen said.
Houston-based Noble Energy reported it has two wells that released natural gas before they were shut during the flood.
"There are no facilities operating under compromised or unknown conditions," said Tisha Schuller, president of the trade group Colorado Oil and Gas Association.
Wes Wilson, a former EPA environmental engineer who, through Be the Change, leads anti-drilling activists in Colorado, said some of the volatile material leaking into water materials from industry facilities will evaporate quickly.
But the sheens visible on surface water are "an indication of heavy crudes left behind," he said. Those materials "now will end up in the soil."
"We are going to have dozens, if not hundreds, of toxic sites," he said, "and they've got to be cleaned up."
Kevin O'Connor, who lives south of Milliken, said until now he was unaware of how much drilling has been done along the St. Vrain near his home. His main exposure to the industry is the oil- and gas-truck traffic that he encounters commuting to work in Denver.
On Thursday, as he walked over a damaged bridge to look at flood-wrecked vehicles, he said, "There's no way to plan for an event like this."
But, he said, the flood has shown that risks are high. "I think we've got better ways to create energy," he said.
This story has been updated to reflect revised spill data released by the Colorado Oil and Gas Conservation Commission.