Iowa DNR

Water Quality Assessments

Impaired Waters List

Iowa River IA 02-IOW-622

from south corporate limit of Wapello (S35, T74N, R3W, Louisa Co.) to Long Cr (S1, T74N, R4W, Louisa Co.)

Assessment Cycle
Release Status
Result Period
1992 - 1994
Assessment Type
Integrated Report
Category 0
Legacy ADBCode
IA 02-IOW-0010_2
Overall Use Support
Aquatic Life Use Support
Fish Consumption
Primary Contact Recreation
Assessment Comments

Assessment is based on results of (1) USGS/NAWQA monitoring at Wapello from 1993-1995.

Basis for Assessment

Relied primarily on USGS WQ monitoring data from Wapello for years 1993 through 1995 (from annual reports on Water Resources Data-Iowa) to assess the B(WW) aquatic life uses as FST due to no violations of WQC during period.   Degree to which Class A uses supported difficult to determine since most flows were > mean monthly flow + 1 SD (i.e., flows materially affected by surface runoff).   In general, however, the summer season data for fecal coliform bacteria at this station are relatively low regardless of flow:  only 2 of seven values exceeded the Class A WQC, and the two non-flow affected values (68 and 100 per 100 ml) were below the WQC.   Thus, use BPJ to assess Class A uses as FST.  Results from fish tissue monitoring for the 1995 RAFT program show that all contaminants in the whole-fish sample of carp were less than 1/2 the FDA action levels; thus, assess support of fish consumption uses as FS.   Support of all uses threatened by agricultural nonpoint sources.

Monitoring and Methods
Assessment Key Dates
240 Non-fixed station physical/chemical (conventional + toxicants)
260 Fish tissue analysis
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