City of Boulder/USGS Water Quality Monitoring
Water Quality Index for August, 2006 at
Boulder Creek Below Coal Creek

Grade D For August, 2006 the WQI rating at Boulder Creek Below Coal Creek (BC-bCC) was Bad (D) due to a WQI value of 44.32. The chart below details the WQI calulations at this site. See the detailed explanation of the WQI method for more information.


Parameter Unit Parameter Value Q-value Weight Factor Total
DO% % sat 119.60 91.53 0.17 15.56
Fecal Coliform #/100 mL 3100.00 13.04 0.16 2.09
pH pH 8.68 61.31 0.11 6.74
Total Phosphate mg PO4/L 0.79 43.87 0.10 4.39
Nitrates mg NO3/L Data Unavailable
Turbidity NTU 100.00 5.00 0.08 0.40
Total Solids mg/l 514.00 20.00 0.07 1.40
Totals (factors, total) 0.69 30.58
Adjusted WQI 44.32

The WQI is computed by converting measured Water Quality Parameters to "Q-Values" using charts developed by the National Sanitation Foundation (NSF) water quality scientists. The Q-Values are then multiplied by a weighting factor based on the importance of that water quality parameter. These values are totaled and then divided by the sum of the weight factors.

WQI at Upstream Station: Boulder Creek Above Coal Creek

WQI at Downstream Station: Middle Boulder Creek @ Nederland WTP

WQI for July at this station

WQI for September at this station

Return to WQI map for August


Thank You! BASIN was a community project which benefitted from over 1000 hours of public volunteer time. BASIN was highlighted by the US EPA in a national case study in its 2001 handbook Delivering Timely Environmental Information to Your Community. Thank you to all volunteers, and especially to the late Jim Waterman, BASIN Project Coordinator!

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Last Page Update - Thursday March 01, 2007