Assessment Comments
Assessment is based on results of (1) IDNR/UHL biological (biocriteria) monitoring in 2004 and (2) IDNR/UHL chemical/physical water quality monitoring in 2003 and 2004.
Basis for Assessment
SUMMARY: The Class B(WW) aquatic life uses are assessed (monitored) as "partially supported” based on results of IDNR/UHL biological (biocriteria) sampling in 2004. Results of IDNR/UHL ambient monitoring in 2003 and 2004 conducted in support of TMDL development, however, suggest good chemical/physical water quality. Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this stream segment.
EXPLANATION: The assessment was based on data collected in 2004 as part of the DNR/UHL stream biocriteria project. The 2004 FIBI score was 56 (good) and the BMIBI score was 45 (fair). The aquatic life use support was assessed as partially supporting (= PS), based on a comparison of the FIBI and BMIBI scores with biological impairment criteria (BIC) established for previous Section 305(b) reports. The biological impairment criteria were determined from a statistical analysis of data collected at stream ecoregion reference sites from 1994-2004. The FIBI BIC for this ecoregion is 53 and the BMIBI BIC for this ecoregion is 62.
In contrast, results of ambient chemcial/physical water quality monitoring suggest relatively good water quality in this river segment. Results from IDNR/UHL ambient monitoring conducted from July 2003 through December 2004 in support of TMDL development show no violations of Class B(WW) criteria for dissolved oxygen, pH, or ammonia (18 samples) or for toxic metals (6 samples analyzed for arsenic, cadmium, chromium, copper, and cyanide) or in the 4 samples analyzed for the pesticide chlorpyrifos. These results suggest “full support” of the Class B(WW) aquatic life uses.
Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this stream segment. Thus, no data are available upon which to base an assessment.
