Using a water quality index to determine and compare creek water quality

摘要

Creek water quality is difficult to characterize and understand. To address this, the National Sanitation Foundation's (NSF's) Water Quality Index (WQI) was used to determine a measurable level for water quality. The purpose of the WQI is to provide a means to conduct a site-to-site comparison and create a baseline of water quality within a watershed. The WQI is a unitless number ranging from 1 to 100 calculated from nine parameters (Hallock, 2002). The higher the number, the better the water quality, with the values generally scored as 90-100 being excellent, 70-90 as good, 50-70 as fair, and 25-50 as poor.