Assessment Comments

Assessment is based on results of IDNR/UHL ambient monthly monitoring from 2000-02 and (2) IDNR/UHL biocriteria sampling in 1998.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses remain assessed (monitored) as "fully supported / threatened" based on results of biological monitoring in 1998.   Fish consumption uses remain assessed "not assessed" due to the lack of fish contaminant monitoring in this river reach.   This assessment is based on (1) results of IDNR/UHL monthly ambient water quality monitoring conducted during the 2000-2002 assessment period at the State Highway 2 bridge 2 miles east of Clarinda (STORET station 10730002 (formerly station 780809)) and (2) results of IDNR/UHL biocriteria monitoring in 1998.  

EXPLANATION:  Results of monitoring at the IDNR/UHL ambient monitoring station east of Clarinda showed no violations of Class B(WW) water quality criteria during the 2000-2002 assessment period for dissolved oxygen (minimum value = 7.7 mg/l), pH (range = 7.4 to 8.5 units), or ammonia-nitrogen (maximum value = 0.90) in the 36 samples analyzed.   In addition, levels of pesticides in the nine samples analyzed were all below the analytical level of detection.   These results suggest "full support" of the Class B(WW) aquatic life uses.   Results of the IDNR biocriteria monitoring in 1998, however, suggest that the Class B(WW) uses are "fully supported / threatened" (see assessment for the 2000 report).  

Fish consumption uses remain "not assessed" due to the lack of recent fish tissue monitoring in this river reach.