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

Grade C For July, 2006 the WQI rating at Boulder Creek Below Coal Creek (BC-bCC) was Medium (C) due to a WQI value of 56.26. 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 119.70 91.21 0.17 15.51
Fecal Coliform #/100 mL 490.00 23.85 0.16 3.82
pH pH 8.71 60.00 0.11 6.60
Total Phosphate mg PO4/L 0.81 43.87 0.10 4.39
Nitrates mg NO3/L Data Unavailable
Turbidity NTU 13.20 67.70 0.08 5.42
Total Solids mg/l 405.00 44.19 0.07 3.09
Totals (factors, total) 0.69 38.82
Adjusted WQI 56.26

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 June at this station

WQI for August at this station

Return to WQI map for July


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Last Page Update - Thursday March 01, 2007