City of Boulder/USGS Water Quality Monitoring
Boulder Creek Watershed
Boulder Creek Water Quality Index

WQI at Boulder Creek at 61st St. for June, 2000

Grade B For June, 2000, the WQI rating at Boulder Creek at 61st St. (BC-61) was Good (B) due to a WQI value of 83.2. The chart below details the WQI calulations at this site. See the detailed explanation of the WQI method for more information.

6-parameter Test result unit Q-value weight factor total
BC-61 6/2000          
DO 97.3 % sat 98 0.17 16.66
Fecal Coliform 170 #/100 mL 40 0.16 6.4
pH 7.67 std units 92 0.11 10.12
Total Phosphate <0.01 mg/L PO4-P 98 0.10 9.8
Nitrates 0.6 mg/L NO3 97 0.10 9.7
Turbidity 2.57 NTU 90 0.08 7.2
totals (factors, total)       0.72 59.88
adjusted WQI         83.2

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.

WQI at Upstream Station: Boulder Creek at 30th St.

WQI at Downstream Station: Boulder Creek at 107th St

WQI at for October, 2000 at this station

Return to WQI map for June, 2000
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 - Tuesday December 27, 2005