Iowa DNR
ADBNet

Water Quality Assessments

Impaired Waters List

Long Dick Creek IA 03-SSK-2007

N. line of S34 (SE1/4) T86N R23W Hamilton Co to headwaters in NE1/4 S8 T87N R23W Hamilton Co.

Assessment Cycle
2022
Release Status
Final
Cycle Period
2018 - 2020
Overall IR Category
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
1/3/2022 10:55:16 AM
Updated
1/14/2022 3:08:17 PM
Assessment conducted in accordance with Iowa's 2022 IR methodology
Use Support
Class A1
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
2010
Impairment Rationale
Single-sample maximum criterion exceeded in significantly > 10% of samples
Data Source
TMDL monitoring: Iowa DNR
TMDL Priority
Tier IV
Class BWW1
Not Supported
Biological: low fish IBI
Support Level
Water in Need of Further Investigation (WINOFI)
Impairment Code
3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.
Cause Magnitude
Moderate
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
Cycle Added
2010
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
Fish Kill: Caused By Animal Waste
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
Agriculture: Intensive Animal Feeding Operations
Source Confidence
N/A
Cycle Added
2006
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
TMDL Priority
Tier III
Fish Kill: Caused By Pesticides
Support Level
Not Supported
Impairment Code
5b - Biological impairment or pollutant-caused fish kill - unknown source. No administrative action.
Cause Magnitude
High
Status
Continuing
Source
Agriculture: Land application
Source Confidence
N/A
Cycle Added
2014
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
TMDL Priority
Tier III
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 presumptive Class BWW1 use was assessed as “not supported” based on multiple fish kill investigations and on biological sampling 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 2008 – 2009

11400004

Long Dick Creek near Ellsworth

Site ldc-2

Iowa DNR

6

BIO

See Below

691

Long Dick Creek

Ellsworth – LDC2


Presumptive Class A1 - Indicator Bacteria: Historical

Site ID

Data Source ID

# Samples / # Years

2008 Geometric Mean

2009 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

11400004

6

26 / 2

369

175

Yes

15

58%

Yes

Evaluated

Not


Presumptive Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

BM Sample Gear

BMIBI score

BMIBI Class

47b BMIBI BIT

BMIBI Pass/Fail

691

10/6/08

16

47b

MS

Art Sub

71

Good

62

Pass


Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage

Riffle Stream?

FIBI score

FIBI Class

47b FIBI BIT

FIBI Pass/Fail

691

10/6/08

16

47b

MS

Yes

24

Poor

53

Fail


Overall:

Community

Assessment Type

Assessment Result

Support Level

IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Pass (1/1)

Full

Fish

Evaluated

Fail (0/1)

Not

Assessment was evaluated because the drainage area of the

Overall

Evaluated

Fail

WINOFI

3bu

site was smaller than the calibrated range.


Presumptive Class BWW1 – Fish kill Assessment:

The presumptive Class BWW1 aquatic life use assessment based on the 2004 and 2011 fish kills resulted in two Category 5b impairments because there were two distinct causes. The fish kills were caused by a “pollutant” or were suspected to be caused by a “pollutant”; therefore, the presumptive Class BWW1 use was considered impaired. Because the sources of the pollutants were not identified and/or the enforcement actions taken against the responsible party have not been resolved, the presumptive Class BWW1 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 2011 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/834

More details about the 2004 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/599



Monitoring and Methods
Assessment Key Dates
8/4/2011 Fish Kill
7/28/2009 Non-fixed Monitoring End Date
10/6/2008 Biological Monitoring
1/7/2008 Non-fixed Monitoring Start Date
4/19/2004 Fish Kill
Methods
140 Incidence of spills and/or fish kills
150 Monitoring data more than 5 years old
315 Regional reference site approach
320 Benthic macroinvertebrate surveys
330 Fish surveys
420 Water column surveys (e.g. fecal coliform)
120 Surveys of fish and game biologists/other professionals
220 Non-fixed station physical/chemical monitoring (conventional pollutant only)