Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Turkey River IA 01-TRK-156

from confluence with N. Br. Turkey R. (S31 T99N R11W Howard Co.) to confluence with S. Br. Turkey R. in S2 T98N R12W Howard Co.

Assessment Cycle
2024
Release Status
Pending
Data Collection Period
Overall IR Category
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
11/1/2023 8:12:46 AM
Updated
12/18/2023 11:21:32 AM
Assessment conducted in accordance with Iowa's 2024 IR methodology.
Use Support
Class A1
Presumptive Use
Not Supported
Bacteria: Indicator Bacteria- E. coli
Support Level
Not Supported
Impairment Code
5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2014
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Watershed project monitoring
TMDL Priority
Tier III
Class BWW2
Fully Supported
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use remains assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2012-2014

15450015

Turkey River @ V46

TR90

Iowa DNR

6

BIO

See Below

1022

Turkey River

US confluence with North Fork Turkey – TK008


Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples / # Years

2012 Geometric Mean

2013 Geometric Mean

2014 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15450015

6

23 / 3

284

606

163

Yes

14

61%

Yes

Evaluated

Not


Presumptive Class A1 - pH:

Site ID

Data Source ID

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15450015

6

24/ 3

8.7

8

8

0

0%

No

Evaluated

Full


Class BWW2 - Binomial Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Acute / Chronic Violations

% Acute/ Chronic Violations

Significantly >10% Violations

Assessment Type

Support Level

15450014

6

Ammonia

16 / 2

0.44

0.09

0.05

0 / 0

0% / 0%

No

Evaluated

Full

15450014

6

Chloride

17 / 3

41

31.9

33

0 / 0

0% / 0%

No

Evaluated

Full

15450014

6

Dissolved oxygen

24 / 3

11

7

7.5

NA / 2

NA / 8%

No

Evaluated

Full

15450014

6

pH

24 / 3

8.7

8

8

0 / NA

0% / NA

No

Evaluated

Full

15450014

6

Temperature

24 / 3

28

14.7

14.5

0 / 0

0% / 0%

No

Evaluated

Full


Class BWW2 - Biological Sampling:

Fish:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/ Fail

1022

8/21/19

28

47c

MS

Undetermined

65

Good

44

Pass

1022

7/31/18

28

47c

MS

Undetermined

63

Good

44

Pass

1022

8/7/17

28

47c

MS

Undetermined

64

Good

44

Pass

1022

8/16/16

28

47c

MS

Undetermined

71

Excellent

44

Pass

Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Fish

Monitored

Pass (4/4)

Full

Assessment was monitored because the assessment used multiple

Overall

Monitored

Pass

Full

1

samples collected in the last five years.


Monitoring and Methods
Assessment Key Dates
4/4/2012 Monitoring Start
11/5/2014 Monitoring End
8/21/2019 Biological Monitoring
8/16/2016 Biological Monitoring
8/7/2017 Biological Monitoring
7/31/2018 Biological Monitoring
Methods
150 Monitoring data more than 5 years old
200 Physical/Chemical Monitoring
315 Regional reference site approach
330 Fish surveys
420 Indicator bacteria monitoring