Here’s a report from Bob Berwyn writing for the Summit County Citizens Voice. Click through and read the whole article. Here’s an excerpt:
The sampling results prompted the Colorado Water Quality Control Division to propose listing the Blue River as impaired under a relatively new rule that sets thresholds for aquatic life use…
Water experts from Summit County and other jurisdictions challenged the initial move to list the Blue River and other stream segments as impaired, claiming that the state-set thresholds — adopted after 10 years of study — may not be applicable in rivers below reservoirs.
For example, Aurora officials questioned whether or not the data collected below a dam should be evaluated as being representative of an entire stream segment. They suggested that changes in natural temperature alterations, low dissolved oxygen, sediment, nutrient composition and hydraulic modifications may alter the biological community below reservoirs.