Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Cedar River IA 02-CED-479

from Rock Cr. nr Orchard (S24 T97N R17W Floyd Co.) to Iowa / Minnesota state line (S8 T100N R18W Mitchell Co.)

Assessment Cycle
1996
Result Period
1992 - 1994
Designations
Assessment Type
Monitored
Integrated Report
Category 0
Legacy ADBCode
IA 02-CED-0110_3
Overall Use Support
Threatened
Aquatic Life Use Support
Threatened
Fish Consumption
Threatened
Primary Contact Recreation
Threatened
Documentation
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.

Monitoring and Methods
Assessment Key Dates
9/30/1999 Fixed Monitoring End Date
9/30/1985 Fixed Monitoring Start Date
Methods
120 Surveys of fish and game biologists/other professionals
260 Fish tissue analysis
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 0
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A