Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Little Sioux River IA 06-LSR-1571

from confluence with Waterman Cr. (S26 T94N R39W O'Brien Co.) to Linn Grove Dam in SW 1/4 S5 T93N R37W Buena Vista Co.

Cycle
2018
Release Status
Final
Overall IR
2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trend
Unknown
Created
7/30/2019 10:56:29 AM
Updated
7/30/2019 10:58:25 AM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
Aquatic Life - Warm Water Type 1
Not Assessed
Class HH
Human Health -
Fully Supported
General Use
General Use water -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 (primary contact recreation) uses and the Class B(WW1) aquatic life uses remain "not assessed" due to the lack of water quality information upon which to base an assessment. Fish consumption uses remain assessed as "fully supported" based on results of U.S. EPA/DNR fish tissue monitoring in 2001 downstream from the Linn Grove dam. Because the data upon which this assessment is based are now older than ten years, the assessment types is considered "evaluated" (a lower confidence assessment).

Assessment Explanation

Fish consumption uses remain assessed (evaluated) as “fully supported” based on results of U.S.EPA/DNR fish contaminant monitoring near Linn Grove Dam in 2001. The composite samples of fillets from channel catfish and walleye had low levels of contaminants. The existence of, or potential for, a fish consumption advisory is the basis for Section 305(b) assessments of the degree to which Iowa’s lakes and rivers support their fish consumption uses. Prior to 2006, DNR used action levels published by the U.S Food and Drug Administration to determine whether consumption advisories should be issued for fish caught as part of recreational fishing in Iowa. In an effort to make Iowa’s consumption more compatible with the various protocols used by adjacent states, the Iowa Department of Public Health, in cooperation with Iowa DNR, developed a risk-based advisory protocol. This protocol went into effect in January 2006. Because the revised (2006) protocol is more restrictive than the previous protocol based on FDA action levels; fish contaminant data that previously suggested “full support” may now suggest either a threat to, or impairment of, fish consumption uses. This scenario, however, does not apply to the fish contaminant data generated from the 2001 RAFT sampling conducted in this segment of the Little Sioux River the levels of contaminants do not exceed any of the new (2006) advisory trigger levels, thus suggesting no justification for issuance of a consumption advisory for this waterbody.

Monitoring and Methods
Assessment Key Dates
8/24/2001
Fish Tissue Monitoring
Methods
150
Monitoring data more than 5 years old
260
Fish tissue analysis