Basis for Assessment
SUMMARY: The Class B(WW) aquatic life uses were assessed as "fully supported / threatened." The fish consumption uses remain "not assessed." EXPLANATION: The previous assessment of support of the Class B(WW) uses ("fully supported / threatened") was based on (1) results from the DNR quarterly monitoring station near Clarinda (station 780809) from October 1991 to September 1993 and (2) results of two DNR stream use assessments in 1991 (see assessment for the 1998 report above). The data from both these sources are now considered too old (greater than five years) for characterizing current water quality conditions. As part of DNR's expanded water quality monitoring program, monthly monitoring at the Clarinda station began in October 1999. Results from this monitoring will allow development of an updated assessment of support of beneficial uses for the 2002 report. The current assessment is based on results of a DNR/UHL biocriteria sampling of fish and benthic macroinvertebrates in 1998. Based on a comparison to results of ecoregion reference site sampling, both the fish and benthic macroinvertebrate communities were rated "fair" (fish IBI=30; MB IBI=59). These results suggest that the Class B(WW) uses are "fully supported / threatened." Fish consumption uses remain "not assessed" due to the lack of recent fish tissue monitoring in this river reach.