City of Boulder/USGS Water Quality Monitoring
Water Quality Index for July, 2002 at
North Boulder Creek diversion to Lakewood

Grade B For July, 2002 the WQI rating at North Boulder Creek diversion to Lakewood (NBC-Lw) was Good (B) due to a WQI value of 87.26. 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 100.16 98.51 0.17 16.75
Fecal Coliform #/100 mL 35.00 54.38 0.16 8.70
pH pH 7.47 93.77 0.11 10.31
Total Phosphate mg PO4/L 0.01 98.23 0.10 9.82
Nitrates mg NO3/L 0.00 100.00 0.10 10.00
Turbidity NTU 1.80 92.95 0.08 7.44
Total Solids mg/l 23.30 84.52 0.07 5.92
Totals (factors, total) 0.79 68.94
Adjusted WQI 87.26

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: Middle Boulder Creek Above North Boulder Creek Confluence

WQI at Downstream Station: North Boulder Creek at Boulder Falls

WQI for June at this station

WQI for August at this station

Return to WQI map for July


INVITATION: BASIN is a community project actively seeking public participation. We appreciate all feedback and welcome comments, suggestions and contributions. To find out more about how you can be involved, click here.

Home | Site Map | Glossary | Bibliography | Contributors
About BASIN | Attribution | Feedback | Search
Last Page Update - Saturday December 24, 2005