Cedar River IA 02-CED-479

Assessment Comments

Assessment remains based on (1) on statewide assessment of freshwater mussels, (2) information from IDNR Fisheries Bureau, and (3) resutls of U.S. EPA/IDNR fish tissue (RAFT) monitoring in 2001.

Basis for Assessment

Of the five samples analyzed for fecal coliforms (P31613), 3 samples exceeded the Class A WQ criterion; 2 of these samples, however, were affected by runoff (i.e., sample flow > mean monthly flow + 1 standard deviation).   Thus, have 1 of three non runoff-affected samples in violation of the WQC.   Thus, use BPJ to assess Class A use as FST.   No violations of Class B WQC at Austin, MN station; thus, assess as FST due to presumed impact of NPS pollution.   Results of monitoring for DO as part of Mitchell dam hydro project upstr at Halvorson Park and at Mitchell dam in summer 1994 suggest no problems with low DO.  Levels of all contaminants < 1/2 FDA action levels in samples of carp and smallmouth bass fillest analyzed for the 1995 RAFT.  Levels of mercury in both samples, however, closely approached 0.500 mg/kg (SMB: 0.481; carp: 0.441), thus, assess fish consumption uses as FST.