Iowa DNR

Water Quality Assessments

Impaired Waters List

Shell Rock River IA 02-SHL-783

from south corporate limit of Shell Rock (S12 T91N R15W Butler Co.) to confluence with Flood Cr. in S27 T93N R16W Butler Co.

Assessment Cycle
Result Period
2002 - 2004
Class B(WW)
Assessment Methodology
Assessment Type
Integrated Report
Category 2a
Legacy ADBCode
IA 02-SHL-0010_2
Overall Use Support
Aquatic Life Use Support
Fish Consumption
Not assessed
Assessment Comments

Assessment is based on results of IDNR/UHL ambient monthly monitoring at Shell Rock, Butler Co., from 2002-04.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses were assessed (monitored) as "fully supported" based on results of IDNR/UHL ambient water quality monitoring conducted during the 2002-2004 assessment period.   [This river segment was not designated for Class A (primary contact recreation) uses during this assessment period.]  Fish consumption uses remain “not assessed” due to the lack of fish contaminant monitoring in this river segment.   The source of data for this assessment is the results of monthly (plus) ambient water quality monitoring from January 2002 through December 2004 at the IDNR/UHL ambient station located at the County Road C45 bridge at Shell Rock, Butler Co.  (STORET station 10120001).  

EXPLANATION:  Monitoring at this station from 2002 through 2004 showed no violations of Class B(WW) water quality criteria for the following parameters:  dissolved oxygen or pH in the 53 samples analyzed; pesticides in the nine samples analyzed; and toxic metals in the 10 samples analyzed during this assessment period.   These results suggest that the Class B(WW) aquatic life uses should be assessed as “fully supported”.   This assessment is consistent with the assessment for the previous (2004) Section 305(b) reporting cycle.  

Fish consumption uses remain “not assessed” due to lack of recent fish tissue monitoring in this river segment.

Monitoring and Methods
Assessment Key Dates
12/2/2004 Fixed Monitoring End Date
1/7/2002 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