Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Yellow River IA 01-YEL-434

mouth (S34 T96N R3W Allamakee Co.) to County Road X-26 bridge in S24 T96N R5W Allamakee Co.

Assessment Cycle
2000
Result Period
1996 - 1998
Designations
Assessment Type
Evaluated
Integrated Report
Category 0
Legacy ADBCode
IA 01-YEL-0070_0
Overall Use Support
Fully
Aquatic Life Use Support
Fully
Fish Consumption
Not assessed
Primary Contact Recreation
Fully
Documentation
Assessment Comments

Assessment based on results of (1) 1998 DNR Biocriteria sampling: Fish IBI= 63(good), BM-IBI= 67(good), (2) DNR monthly WQ monitoring at Volney, and (3) WQ monitoring at Sny Magill / Bloody run project site near mouth.

Basis for Assessment

[NOTE:  The narrative of the assessment developed for, and published in, the 2000 Section 305(b) report for this segment was incorrect.   The correct narrative is included below:]
  
SUMMARY:  The Class A (primary contact recreation) uses were assessed (evaluated) as "fully supported."  The Class  B(WW) aquatic life were assessed (evaluated) as "fully supported."  Fish consumption uses remain "not supported."  The source of data for this assessment was results of IDNR quarterly ambient monitoring at the station east of Volney from October 1997 through September 1999.   EXPLANATION:  No violations of the Class A WQ criterion occurred during the 2000 biennial period.   The geometric mean of fecal coliform bacteria in the two non-flow affected samples was 143 orgs/100 ml; neither sample contained a level of fecal coliforms above the U.S.  EPA single-sample maximum value of 400 orgs/100 ml =FS?).   No violations of Class B(WW) water quality criteria for either conventional or toxic pollutant occurred in the quarterly samples collected during this two year period.   Based on methods for assessing support of primary  contact uses as described in 1998 Section 305(b) reporting  guidelines (p.  3-34), the data from this station suggest full support of these uses.   This assessment was based on results of quarterly monitoring.   Thus, due to lack of sufficient number of  samples to make "monitored" assessments, the assessments of support of the Class A and Class B(WW) uses designated for this reach are considered "evaluated."  Results from stations monitored monthly or more frequently 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 Volney station began in October 1999.   Results of this monitoring will be used for future Section 305(b) assessments.   Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this river segment.

Causes and Sources of Impairment
Causes Use Support Cause Magnitude Sources Source Magnitude
Pathogens Overall Use Support Not Impairing
  • Source Unknown
  • Not Impairing
Pathogens Primary Contact Recreation Not Impairing
  • Source Unknown
  • Not Impairing