State water quality declining, report says

SUMMIT COUNTY — Continued population growth, together with oil and gas development, represent intensifying threats to water quality in the state, according to a new report from Environment Colorado.

Using data from the EPA and the Colorado Water Quality Control Division the report concludes that water quality in Colorado has declined in recent years. The percentage of Colorado streams deemed fishable or swimmable declined by 7 percent, while the number of stream segments classified as impaired rose 53 percent between 1998 and 2006.

But at least part of that reported decline is due to better data collection and monitoring, said Steve Gunderson, director of the state’s water quality control division.

“The number one reason we see more impairments is we have more data. And standards are tighter,” Gunderson said. The most common pollutant statewide is selenium, affecting 25 percent of all impaired stream reaches. Second on the list is zinc, a common pollutant from abandoned mines that affects Summit County’s watersheds.

With cleanups in various stages of planning and execution, and stringent controls on discharges, water quality in Summit County is holding its own, said Lane Wyatt, of the Northwest Colorado Council of Governments.

A fairly complete historical record of data shows that water quality in Dillon Reservoir remains outstanding, Wyatt said. Similarly, monitoring from some other locations shows improved water quality, including Straight Creek (flowing down from the Eisenhower Tunnel to Dillon). Intensive work by the Colorado Department of Transportation has paid off in that drainage by measurably reducing sediment loading, according to Wyatt.

Statewide assessment

Making a statewide assessment of water quality is not easy, Gunderson said. The number of streams and rivers being monitored continues to grow, and with new information coming in, the picture keeps changing. But in some parts of the state, water quality has clearly improved since passage of the Clean Water Act in the 1970s, he said.

Concluding that water quality has declined statewide in the past six years is an over-simplification, Gunderson said. But he acknowledged that pressures from population growth, development, oil and gas drilling, as well as climate change, represent very real threats. The issue of pollution from things like agricultural uses and urban runoff continues to vex water quality experts.

The lack of statewide data to make a comprehensive assessment of water quality is addressed directly by the Environment Colorado report.

“There just aren’t enough cops on the beat,” said Stephanie Thomas, the primary author. Thomas said, that, based on the data reported by the state and the EPA, she stands by the conclusion that Colorado’s water is in worse shape than it was half a decade ago.

“Water quality declined and we expect it to continue,” Thomas said.

With only a small staff of field inspectors, the state’s water quality division is swamped, she said. Thomas said that less than 1 percent of sites under stormwater runoff permits are inspected annually.

“That’s not enough to have a deterrent effect,” she said.

Gunderson acknowledged the staffing challenges and said that water quality enforcement has made some progress in the past few years, winning funding from the Colorado Legislature to add personnel.