Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Mud Creek IA 06-BSR-1546

mouth (S26 T98N R46W Lyon Co.) to the IA-MN state line

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
12/28/2021 9:34:42 AM
Updated
1/10/2022 10:04:52 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2008
Impairment Rationale
Geometric mean criterion exceeded
Data Source
TMDL monitoring: Iowa DNR
TMDL Priority
Tier III
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
New
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2022
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Ambient monitoring: adjacent state
TMDL Priority
Tier IV
Class BWW2
Aquatic Life - Warm Water Type 2
Not Supported
Support Level
Not Supported
Impairment Code
5b - Biological impairment or pollutant-caused fish kill - unknown source. No administrative action.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2006
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
TMDL Priority
Tier IV
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
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
New
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2022
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Ambient monitoring: adjacent state
TMDL Priority
Tier IV
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 use was assessed as "not supported" due to levels of indicator bacteria and pH that violated state water quality criteria. The Class BWW2 use was assessed as “not supported” based on biological sampling data, the occurrence of a fish kill and due to violations of the pH water quality criteria.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

MNPCA

15

WQ

CY 2018-2019

99990103

Mud Creek

Iowa DNR

6

BIO

See Below

399

Mud Creek

Lester – REMAP #136

Iowa DNR

6

BIO

See Below

504

Mud Creek

Alvord – REMAP #175

Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2018/ 2019/2020)

2018 Geometric Mean

2019 Geometric Mean

2020 Geometric Mean

Violates Annual Geometric Mean?

# 2018 SSM violations / SSM Violations needed for impairment

# 2019 SSM violations / SSM Violations needed for impairment

# 2020 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

99990103

15

6/5/0

748

1397

NA

YES

5 / NA

4 / NA

NA

NA

Evaluated

Not

Class A1 – pH:

Site ID

Data Source ID

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

99990103

15

11 / 2

6.24

9.12

8.52

3

3

YES

Monitored

Not

Class BWW2 - Conventional Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

# Violations

# Acute / Chronic Violations

Violations needed for impairment

Violates Significantly >10% Rule?

Assessment Type

Support Level

99990103

15

Dissolved Oxygen

11 / 2

6.92

12.25

9.65

0

NA / NA

3

NO

Monitored

Full

99990103

15

pH

11 / 2

6.24

9.12

8.52

3

NA / NA

3

YES

Monitored

Not

99990103

15

Temperature

11 / 2

5.2

17.4

14.1

0

NA / NA

3

NO

Monitored

Full


Class BWW2 - Biological Sampling:


Benthic Macroinvertebrates:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

47a BMIBI BIT

BMIBI Pass/Fail

504

8/29/05

126

47a

MO

Hess

26

Poor

54

Fail

399

7/21/04

80

47a

MO

Art Sub

58

Good

54

Pass

Fish:

Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47a FIBI BIT

FIBI Pass/Fail

504

8/29/05

126

47a

MO

NA

13

Poor

43

Fail

399

7/21/04

80

47a

MO

NA

20

Poor

43

Fail

Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (1/2)

Not

Fish

Evaluated

Fail (0/2)

Full

Assessment was evaluated because the samples used to complete the

Overall

Evaluated

Fail

Not

5bt

assessment were not collected in a recent five year period.


Class BWW2 – Fish kill Assessment:

The Class BWW2 aquatic life use assessment based on the 2003 fish kill placed this segment in Category 5b. The fish kill was caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the Class BWW2 use was considered impaired. Because the source of the pollutant was not identified and/or the enforcement actions taken against the responsible party have not been resolved, the Class BWW2 use was placed in Category 5b. Due to uncertainty regarding the recovery of the aquatic life following the fish kill, any existing fish kill 5b impairment will remain in Category 5b until more recent sampling has shown recovery of the aquatic community or the responsible party has paid restitution.


More details about the 2003 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/574

Monitoring and Methods
Assessment Key Dates
4/25/2018
Fixed Monitoring Start Date
8/28/2019
Fixed Monitoring End Date
9/10/2003
Fish Kill
7/21/2004
Biological Monitoring
8/29/2005
Biological Monitoring
Methods
140
Incidence of spills and/or fish kills
150
Monitoring data more than 5 years old
210
Fixed station physical/chemical monitoring (conventional pollutants only)
315
Regional reference site approach
320
Benthic macroinvertebrate surveys
330
Fish surveys
420
Indicator bacteria monitoring