Iowa River IA 02-IOW-628

Assessment Comments

Assessment is based on results of routine water quality & fish tissue monitoring as part of the UI/ACOE Coralville Water Quality Study.

Basis for Assessment

Of the 18 samples collected in 1992 and 1993, only 5 were collected during approx average flows; of these, only 1 sample had fecals exceeding the Class A WQC; thus assess Class A use with BPJ as FS.   Of the 72 samples analyzed for NO3, only 4 contained more than 10 mg/l; DW advisory, however, issued in Dec 91 for NO3; assess Class C use as PS.   None of the approx 40 samples contained levels of Class B toxics that exceeded WQC; thus, assess Class B uses as FS.   Overall assess set at FST due to known threat from ag.  NPS.   (High level of chlordane in 1992 RAFT sample not extended upstr of Burlington St.