Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Yellow River IA 01-YEL-437

from N. Fk. Yellow R. (S13 T96N R7W Allamakee Co.) to confluence with unnamed tributary in SE 1/4 S8 T96N R7W Winneshiek Co.

Cycle
2020
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
8/27/2020 2:10:28 PM
Updated
10/16/2020 7:04:45 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2008
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Special project/study: Iowa DNR
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2016
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Special project/study: Iowa DNR
TMDL Priority
Tier IV
Class BWW2
Aquatic Life - Warm Water Type 2
Partially Supported
Support Level
Partially Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2014
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Special project/study: Iowa DNR
TMDL Priority
Tier III
Support Level
Partially Supported
Impairment Code
5b-t - Biological - tentative
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2004
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
TMDL Priority
Tier IV
General Use
General Use water -
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 levels of indicator bacteria (E. coli) that exceeded state water quality criteria and "partially supported" due to pH levels that exceeded the upper pH water quality criterion. The Class BWW2 use remains assessed as “partially supported” based on biological sampling data and also based on violations of the Class BWW2 criterion for pH. Note: A TMDL for the bacterial impairment for Yellow River basin streams was prepared by Iowa DNR in 2012 and was approved by U.S. EPA in February 2013. Due to TMDL completion, the Integrated Report category for the Class A1 recreational use was changed from 5p to 4a.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY2011 & CY2014

11960006

Yellow River near Castalia

Site YeRi3

Iowa DNR

6

WQ

CY2011 & CY2014

15960002

Yellow River at 107 Ave

Iowa DNR

6

BIO

See Below

568

Yellow River

Postville – Site YeRi1

Iowa DNR

6

BIO

See Below

579

Yellow River

Castalia – Site YeRi3

Iowa DNR

6

BIO

See Below

580

Yellow River

Castalia – Site YeRi4

Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples / # Years

2014 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11960006

6

20 / 1

601

Yes

15

75%

Yes

Evaluated

Partial

15960002

6

20 / 1

1661

Yes

17

85%

Yes

Evaluated

Not

Class A - pH:

Site ID

Data Source ID

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11960006

6

14 / 1

9.6

8.6

8.6

4

29%

Yes

Evaluated

Partial

15960002

6

14 / 1

9.2

8.43

8.45

1

7%

No

Evaluated

Full

Class BWW2 - Conventional 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

11960006

6

Ammonia

8 / 1

0.09

0.06

0.05

0 / 0

0% / 0%

No

Evaluated

Full

11960006

6

Dissolved Oxygen

14 / 1

16

9

8.3

0 / 0

0% / 0%

No

Evaluated

Full

11960006

6

pH

14 / 1

9.6

8.6

8.6

4 / 0

29% / 0%

Yes

Evaluated

Partial

11960006

6

Temperature

14 / 1

21.7

14.3

14.7

NA / 0

NA / 0%

No

Evaluated

Full

15960002

6

Ammonia

8 / 1

016

0.08

0.05

0 / 0

0% / 0%

No

Evaluated

Full

15960002

6

Dissolved Oxygen

14 / 1

15

8.4

7.5

0 / 0

0% / 0%

No

Evaluated

Full

15960002

6

pH

14 / 1

9.2

8.43

8.45

1 / 0

7% / 0%

No

Evaluated

Full

15960002

6

Temperature

14 / 1

23.6

14.7

15.4

NA / 0

NA / 0%

No

Evaluated

Full

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

52b BMIBI BIT

BMIBI Pass/ Fail

568

7/25/07

20

52b

MS/WW

Hess

70

Good

61

Pass

568

8/1/06

20

52b

MS/WW

Hess

74

Good

61

Pass

Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

52b FIBI BIT

FIBI Pass/ Fail

580

7/26/07

10

52b

MS/WW

NA

58

Good

52

Pass

568

7/25/07

20

52b

MS/WW

NA

48

Fair

52

Fail

579

7/25/07

13

52b

MS/WW

NA

49

Fair

52

Fail

568

8/1/06

20

52b

MS/WW

NA

46

Fair

52

Fail

Overall:

Community

Assessment Type

Assessment Result

Support Level

Earned IR Category

Actual IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (2/2)

Full

Fish

Evaluated

Fail (1/4)

Partial

Overall

Evaluated

Fail

Partial

3bc

5bt

Assessment is evaluated because the samples included in the assessment weren’t collected in the last five years.

Monitoring and Methods
Assessment Key Dates
8/1/2006
Biological Monitoring
7/25/2007
Biological Monitoring
4/18/2011
Fixed Monitoring Start Date
10/25/2011
Fixed Monitoring End Date
4/24/2014
Fixed Monitoring Start Date
10/8/2014
Fixed Monitoring End Date
7/26/2007
Biological Monitoring
2/1/2013
TMDL Completed
Methods
150
Monitoring data more than 5 years old
220
Non-fixed station physical/chemical monitoring (conventional pollutant only)
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
420
Indicator bacteria monitoring