Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Wolf Creek IA 05-CHA-1339

mouth (S15 T71N R21W Lucas Co.) to confluence with unnamed tributary in E 1/2 NW 1/4 S8 T70N R22W Wayne Co.

Cycle
2020
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Stable
Created
9/30/2020 1:57:40 PM
Updated
10/12/2020 1:02:00 PM
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
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2008
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Ambient monitoring: Corps of Engineers/Iowa DNR/ISU
TMDL Priority
Tier III
Class BWW2
Aquatic Life - Warm Water Type 2
Partially Supported
Support Level
Partially Supported
Impairment Code
5b-v - Biological - verified
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2008
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
TMDL Priority
Tier IV
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2016
Impairment Rationale
Significantly > 10% of days fail to meet 24-hour criteria
Data Source
Special project/study: Iowa DNR
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2016
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Special project/study: Iowa DNR
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. The Class BWW2 use remains assessed as “partially supported” based on biological sampling data and on continuous dissolved oxygen and temperature monitoring data.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

USACE

12

WQ

CY 2010-2014

15590003

Wolf Creek at CR H50/430th (Site RA-41)

USACE

12

WQ

CY 2010-2014

15930007

Wolf Creek at CR S23/100th (Site RA-44)

Iowa DNR

6

BIO

See Below

207

Wolf Creek

Chariton

Presumptive Class A1 - Indicator Bacteria: 2010-2012

Site ID

Data Source ID

# Samples / # Years

2010 Geometric Mean

2011 Geometric Mean

2012 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15590003

12

19 / 3

959

185

2469

Yes

15

79%

Yes

Evaluated

Not

15930007

12

15 / 3

470

138

632

Yes

8

53%

Yes

Evaluated

Partial

Presumptive Class A1 - pH: 2012-2014

Site ID

Data Source ID

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15590003

12

53 / 3

8

7.5

7.6

0

0%

No

Evaluated

Full

15930007

12

35 / 3

8

7.9

7.5

0

0%

No

Evaluated

Full

Class BWW2 - Conventional Parameters: 2012-2014

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

15590003

12

Ammonia

28 / 3

0.66

0.11

0.05

0 / 0

0% / 0%

No

Evaluated

Full

15930007

12

Ammonia

21 / 3

0.7

0.12

0.05

0 / 0

0% / 0%

No

Evaluated

Full

15590003

12

Chloride

34 / 3

14

6.8

6.4

0 / 0

0% / 0%

No

Evaluated

Full

15930007

12

Chloride

14 / 3

13

7.2

6.7

0 / 0

0% / 0%

No

Evaluated

Full

15590003

12

Dissolved oxygen

53 / 3

11.7

8.3

7.9

NA / 1

NA / 2%

No

Evaluated

Full

15930007

12

Dissolved oxygen

35 / 3

12.3

8.4

8.2

NA / 1

NA / 3%

No

Evaluated

Full

15590003

12

pH

53 / 3

8

7.5

7.6

0 / NA

0% / NA

No

Evaluated

Full

15930007

12

pH

35 / 3

8

7.9

7.5

0 / NA

0% / NA

No

Evaluated

Full

15590003

12

Temperature

53 / 3

27.5

17.1

17.8

0 / 0

0% / 0%

No

Evaluated

Full

15930007

12

Temperature

35 / 3

25.1

16.3

18.1

0 / 0

0% / 0%

No

Evaluated

Full

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/ Thermal

BM Sample Gear

BMIBI score

BMIBI Class

40a BMIBI BIT

BMIBI Pass/ Fail

207

9/14/15

66

40a

MO/WW

Hess

37

Fair

41

Fail

207

8/3/15

66

40a

MO/WW

Hess

43

Fair

41

Pass

207

9/12/12

66

40a

MO/WW

ArtSub

27

Poor

41

Fail

207

8/24/12

66

40a

MO/WW

ArtSub

36

Fair

41

Fail

Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/ Thermal

Riffle Stream?

FIBI score

FIBI Class

40a FIBI BIT

FIBI Pass/ Fail

207

9/14/15

66

40a

MO/WW

NA

17

Poor

33

Fail

207

9/12/12

66

40a

MO/WW

NA

23

Poor

33

Fail

Overall:

Community

Assessment Type

Assessment Result

Support Level

Earned IR Category

Actual IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (1/4)

Partial

Fish

Evaluated

Fail (0/2)

Not

Overall

Evaluated

Fail

Partial

3bc

5bv

Assessment was evaluated because it included samples not collected in the last five years.

Class BWW2 – Continuous Monitoring Data:

The results of continuous dissolved oxygen (DO) and temperature monitoring in 2012 for the DNR/SHL sampling project do suggest impairment of Class BWW2 aquatic life uses. The lowest DO concentration recorded in 69 days of continuous monitoring was 2.1 mg/L. The daily DO minimum concentration failed to meet the 24-hour DO criterion (4 mg/L) in 29 of 69 days and the 16-hour DO criterion (5 mg/L) in 9 of 69 days. The percentages exceeding the 24-hour and 16-hour DO criteria (42.0% and 13.0%, respectively) were greater than (failing) the 10% impairment threshold used to assess conventional water quality parameters. The associated statistical analysis confidence level for the 24-hour analysis result was high (>90%), while the confidence level for the 16-hour analysis result was not high (<90%). The maximum stream temperature recorded during the sensor deployment period was 34.2 degrees (C). The temperature criterion for warm water interior streams (32 C) was exceeded in 15 of 69 days. The percentage exceeding (21.7%) was greater than (failing) the 10% impairment threshold with high statistical confidence (>90%). Based on these data, the BWW2 aquatic life use was assessed as impaired for DO and temperature. The assessment type is “evaluated” because it is based on data collected from a single year within the current data assessment period. In order to meet the requirements for a “monitored” assessment, the DNR’s continuous monitoring assessment methodology requires monitoring data from two or more years within the assessment period.


Monitoring and Methods
Assessment Key Dates
3/15/2012
Fixed Monitoring Start Date
10/21/2014
Fixed Monitoring End Date
9/12/2012
Biological Monitoring
8/3/2015
Biological Monitoring
7/4/2012
Non-fixed Monitoring Start Date
9/10/2012
Non-fixed Monitoring End Date
9/14/2015
Biological Monitoring
3/22/2010
Fixed Monitoring Start Date
10/22/2012
Fixed Monitoring End Date
8/24/2012
Biological Monitoring
Methods
150
Monitoring data more than 5 years old
210
Fixed station physical/chemical monitoring (conventional pollutants only)
222
Non-fixed-station monitoring (conventional during key seasons and flows)
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
420
Indicator bacteria monitoring