Iowa DNR

Water Quality Assessments

Impaired Waters List

Cedar River IA 02-CED-472

from W. Fk. Cedar R. (S4, T90N, R14W, Black Hawk Co.) to lowhead dam at Waverly in NW 1/4, S2, T91N, R14W, Bremer Co.

Assessment Cycle
Release Status
Result Period
1996 - 1998
Assessment Type
Integrated Report
Category 0
Legacy ADBCode
IA 02-CED-0070_0
Overall Use Support
Aquatic Life Use Support
Fish Consumption
Not assessed
Assessment Comments

Assessment is based on results of IDNR ambient monthly monitoring near Janesville.

Basis for Assessment

SUMMARY:  Assessed support of the Class B(WW) aquatic life uses as "fully supported."  Fish consumption uses remain "not assessed."  EXPLANATION:  Results of DNR quarterly water quality monitoring in 1998 and 1999 from the DNR quarterly station located at Janesville showed no violations of WQ criteria to protect the Class B(WW) aquatic life uses:  no violations of state water quality criteria conventional or toxic parameters (dissolved oxygen, pH, and ammonia-nitrogen) occurred in the 8 samples collected during this monitoring period; neither of the two samples analyzed for toxic metals showed violations of state criteria.   Thus, the Class B(WW) aquatic life uses were assessed as "fully supported."  This assessment was based on results of quarterly monitoring.   Results from stations monitored monthly or more frequently, however, are preferred for Section 305(b) assessments in order to improve the accuracy and confidence level of the assessement.   As part of DNR's expanded water quality monitoring program, monthly monitoring at the Janesville station began in October 1999.    Due to lack of fish contaminant monitoring in this river reach, fish consumption uses remain "not assessed."  Based on the limited water quality data that are available, water quality conditions appear to fully support the designated aquatic life uses.   Additional water quality monitoring and/or follow-up biological monitoring would be useful for better determining the degree to which the Class B(WW) uses are supported.

Monitoring and Methods
Assessment Key Dates
9/5/2001 Fixed Monitoring End Date
10/25/1999 Fixed Monitoring Start Date
230 Fixed station physical/chemical (conventional plus toxic pollutants)
Monitoring Levels
Biological 0
Habitat 0
Physical Chemistry 3
Toxic 0
Pathogen Indicators 0
Other Health Indicators 0
Other Aquatic Life Indicators 0
# of Bio Sites 0
BioIntegrity N/A
Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude