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

Relatively low levels of fecal coliforms; only 2 violations of Class A WQC in 16 non-flow-affected samples with geometric mean = 57; thus, assess Class A uses as FST.   No violations of Class B toxics during 3-year period; only 1 of 45 samples violated Class B(WW) WQC for dissolved oxygen; thus, assess Class B uses as FST due to known threats from ag and urban NPSs.   Based on results of 1994 DNR study of fish tissue contamination, assess fish consumption uses as FS.   No violations of Class C WQC, including NO3, in 65 samples collected during three-year period; thus, assess Class C uses as FST due to continuing threat of agricultural and urban NPS runoff.