Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Little Turkey River IA 01-TRK-163

from south line of S11 T90N R3W (Delaware Co.) to confluence with unnamed tributary in the S 1/2 of S15 T90N R3W Delaware Co.

Cycle
2024
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
11/1/2023 8:14:02 AM
Updated
12/14/2023 10:56:55 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.
Cause Magnitude
High
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2012
Impairment Rationale
Geometric mean criterion exceeded
Data Source
TMDL monitoring: Iowa DNR
TMDL Priority
Tier III
Class BWW2
Aquatic Life - Warm Water Type 2
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use remains assessed as “not supported” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). All other designated uses were “not assessed.”

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2010

11280003

Little Turkey River @ Colesburg

Site ltr2


Presumptive Class A1 - Indicator Bacteria: Historical

Site ID

Data Source ID

# Samples / # Years

2010 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11280003

6

8 / 1

914

Yes

7

88%

Yes

Evaluated

Not


Class BWW2 – No Data

Class HH - No Data

Monitoring and Methods
Assessment Key Dates
3/10/2010
Monitoring Start
7/26/2010
Monitoring End
Methods
150
Monitoring data more than 5 years old
420
Indicator bacteria monitoring