The August 5 disaster happened when a mine in southwest Colorado that was in the process of a cleanup was opened, releasing millions of gallons of polluted water that then flowed into the watershed below the mine.

In evaluating the cause and aftermath of the breach of the abandoned Gold King mine that spewed 3 million gallons of toxic wastewater into the environment, the Bureau of Reclamation put most of the onus on the Environmental Protection Agency.

The bureau's recent report stated that EPA workers, while conducting remediation procedures on the mine in San Juan County, Colo., did not directly measure the level of water in a sealed up mine pool before opening the mine, a step that could have avoided the disaster that followed.

Instead of drilling holes to accurately gauge the water level, workers just estimated that level. EPA officials have stated that test drilling was not conducted, as it had been on other jobs, due to the steepness of the site, cost, technical and safety issues among other factors.

The mine blowout occurred on Aug. 5 of this year and made parts of the Animus River a toxic orange. The report did note however, that throughout the history of mining in that part of southwest Colorado, an estimated 8.6 million tons of mine tailings have polluted the river. Lessening the EPA workers' culpability a little more was the finding that the mine was improperly sealed in the past and could have failed on its own in due time.