TransCanada now believes the Keystone pipeline has leaked about 16,800 gallons in South Dakota, a dramatic increase from initial estimates.
The leak was discovered on Saturday and forced a key section of the controversial pipeline to be shut down. TransCanada ( initially told regulators the spill totaled about 187 gallons of oil.
TransCanada told CNNMoney that while the company has "made progress" in trying to find the source of the leak, it has "yet to pinpoint the source."
Despite that, TransCanada said the spill has been "controlled" because the pipeline was shut down immediately after it was reported and valves and pump stations were shut down remotely. The company said visual inspections confirmed the valves were closed.
"There is no significant environmental impact observed," TransCanada said.
TransCanada said a crew of about 100 people continue to work "around the clock" with regulators at the site, which is about four miles from its Freeman pump station in Hutchinson County, South Dakota.
The company now tells regulators the spill totals roughly 400 barrels, which is equal to about 16,800 gallons. The new oil spill estimate was based on the safe excavation of soil to expose more than 100 feet of pipe, the company said. The estimate includes the amount of oil observed in the soil and the "potential area impacted."
TransCanada said it has "taken this incident very seriously" and continues to work with federal and state regulatory agencies.
Still, environmentalists criticized TransCanada over the oil spill.
The "disaster is a stark reminder that it's not a question if a pipeline will malfunction, but rather a question of when," Michael Brune, executive director of the Sierra Club, wrote in a statement. "
Environmental concerns led President Obama to deny a permit to expand the Keystone pipeline last year. TransCanada has challenged that denial in U.S. federal court.
SOURCE: CNN MONEY