Colorado Impaired Waterways Information: 303(d) Listing
The Clean Water Act [LINK]Section 303(d) listing Colorado[/LINK] requires states to identify waters that are not expected to meet the national goal of “fishable, swimmable” and to develop Total Maximum Daily Loads (the maximum amount of a pollutant that a water body can receive and still meet water quality standards), and an allocation of that amount to the pollutant’s sources.
Water Quality in St. Vrain/Boulder Creek Watershed
Water quality in the St. Vrain/Boulder Creek watershed is good overall; however, elevated levels of Escherichia coli (E. coli), which is a fecal indicator bacteria, are present in portions of both the urban and agricultural areas of the watershed. Fecal indicator bacteria such as E. coli are used to indicate the potential presence of pathogens (disease-causing organisms) associated with fecal contamination.
Fecal indicator bacteria can originate from:
- Human sources
- Sources in the environment
Phosphorus & Nitrogen Standards
Total phosphorus and total nitrogen stream standards are not yet applicable to streams in the watershed. Future compliance with interim values adopted by the Colorado Water Quality Control Commission in 2012 is expected to be a significant challenge for waste water treatment plants. It should be noted that coal-fired power plants, automobiles and agricultural activities release contaminants such as nitrate which can cause atmosphere deposition in the upper watershed such as Rocky Mountain National Parks lakes.