Colorado's list of polluted waters has grown to 117 river, stream and lake segments, the highest number in the 15 years the state has tracked such problems.
Approved Wednesday by the state Water Quality Control Commission, the list of "impaired" waters includes stretches in every major river basin including the Colorado and South Platte and involves nearly two dozen contaminants harming fish and degrading water.
One high-profile listing was Boulder Creek, parts of which are tainted with the E. coli bacteria which can sicken people.
Some sections were added over the objections of local governments ultimately concerned about costly water-protection needs. Those included stretches of the Arkansas and Colorado rivers, where elevated levels of selenium an element toxic to fish are leached out of soil and carried into the river via agricultural and suburban runoff.
But several other troubled river stretches were left off the list, some over the objections of both the Environmental Protection Agency and conservation groups. In most cases, commissioners said there wasn't enough convincing pollution data to add the streams to the list.
An EPA official said the agency will register its distress that Colorado left off five segments including a part of the South Platte River downstream from the Metro Wastewater Reclamation District which treats sewage for much of the Denver region as well as the West Fork of Clear Creek downstream from Climax Molybdenum Co. EPA's concerns could pressure state regulators to add the segments later.
Environmentalists, meanwhile, had targeted two streams: Bear Creek in Jefferson County and the Dolores River below McPhee Reservoir in southwestern Colorado. Fish in both streams have suffered significantly from low water flows, rising water temperatures and other problems. But commissioners said no.