Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Jordan Creek IA 05-CHA-1330

mouth (S1 T70N R21W Wayne Co.) to confluence with unnamed tributary in E 1/2 NW 1/4 S26 T70N R21W Wayne Co.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Stable
Created
12/29/2021 9:34:28 AM
Updated
1/28/2022 1:36:16 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
High
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
Not Supported
Support Level
Not Supported
Impairment Code
5b-t - Biological - tentative
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2006
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
High
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2016
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Biological monitoring: Iowa DNR WQMA
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
Biological monitoring: Iowa DNR WQMA
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The presumptive Class A1 use was 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 “not supported” based on biological sampling data and 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

15930004

Jordan Creek at CR J32 (Site RA-37)

Iowa DNR

6

BIO

See Below

907

Jordan Creek

Millerton


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

15930004

12

16 / 3

1317

251

656

Yes

14

88%

Yes

Evaluated

Not


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

15930004

12

36 / 3

8.3

7.7

7.7

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

15930004

12

Ammonia

22 / 3

0.67

0.09

0.05

0 / 0

0% / 0%

No

Evaluated

Full

15930004

12

Chloride

15 / 3

16

7.7

7.6

0 / 0

0% / 0%

No

Evaluated

Full

15930004

12

Dissolved oxygen

36 / 3

13.5

9.2

9

NA / 0

NA / 0%

No

Evaluated

Full

15930004

12

pH

36 / 3

8.3

7.7

7.7

0 / NA

0% / NA

No

Evaluated

Full

15930004

12

Temperature

36 / 3

28.2

17.3

18.9

0 / 0

0% / 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

40a BMIBI BIT

BMIBI Pass/Fail

907

9/12/12

18

40a

MO

ArtSub

13

Poor

41

Fail


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

40a FIBI BIT

FIBI Pass/Fail

907

9/12/12

18

40a

MO

NA

24

Poor

33

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/1)

Not

Fish

Evaluated

Fail (0/1)

Not

Overall

Evaluated

Fail

Not

5bt

Assessment was evaluated because it was based on an old single sample.


Class BWW2 – Continuous Monitoring Data:

The results of additional continuous monitoring for dissolved oxygen (DO) and temperature suggested impairment of the Class BWW2 use. Continuous monitoring data collected in 2012 by DNR/SHL for TMDL/SI purposes were examined for DO and stream temperature criteria violations. The lowest DO concentration recorded in 29 days of continuous monitoring was 1.6 mg/L. The daily DO minimum concentration failed to meet the 24-hour DO criterion (4 mg/L) in 19 of 29 days and the 16-hour DO criterion (5 mg/L) in 9 of 29 days. The percentages exceeding the 24-hour and 16-hour DO criteria (65.5% and 31.0%, respectively) were greater than (failing) the 10% impairment threshold used to assess conventional water quality parameters. The associated statistical analysis confidence level was high (>90%). The maximum stream temperature recorded during the sensor deployment period was 34.9 degrees (C). The temperature criterion for warmwater interior streams (32 C) was exceeded in 14 of 29 days. The percentage exceeding (48.3%) was greater than (failing) the 10% impairment threshold with high statistical confidence (>90%). Based on these data, the BWW2 aquatic life use is 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
3/14/2012
Fixed Monitoring Start Date
10/21/2014
Fixed Monitoring End Date
9/12/2012
Biological Monitoring
7/3/2012
Non-fixed Monitoring Start Date
7/31/2012
Non-fixed Monitoring End Date
3/6/2010
Fixed Monitoring Start Date
10/22/2012
Fixed Monitoring End Date
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