Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

North Fork Maquoketa River IA 01-NMQ-91

confluence with Bear Cr (S31 T89NR2W Dubuque Co.) to confluence with unnamed tributary in S18 T90N R1W Dubuque Co.

Cycle
2020
Release Status
Final
Overall IR
4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend
Unknown
Created
6/10/2020 12:33:45 PM
Updated
10/14/2020 2:50:18 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW2
Aquatic Life - Warm Water Type 2
Not Supported
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
High
Status
Continuing
Source
Agriculture
Source Confidence
N/A
Cycle Added
1998
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
High
Status
Continuing
Source
Agriculture
Source Confidence
N/A
Cycle Added
1998
Impairment Rationale
Pollutant-caused fish kill
Data Source
Fish kill investigation: Iowa DNR
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
High
Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2020
Impairment Rationale
Low Biotic Index
Data Source
Biological monitoring: Iowa DNR WQMA
General Use
General Use water -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class BWW2 aquatic life use remains assessed as “not supported” due to: (1) biological sampling data and (2) the multiple fish kill investigations. All other designated uses were "not assessed". Note: A TMDL for this biological impairment was approved by U.S. EPA in April 2007. Due to completion and approval of the TMDL, the Category for the Class BWW2 use was changed from 5a (impaired; TMDL needed) to 4a (impaired; TMDL approved).

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

BIO

See Below

262

North Fork Maquoketa River

Dyersville – TMDL #28

Iowa DNR

6

BIO

See Below

263

North Fork Maquoketa River

New Vienna – TMDL #29

Presumptive Class A1 – No Data

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

BM Sample Gear

BMIBI score

BMIBI Class

47c BMIBI BIT

BMIBI Pass/ Fail

262

7/25/05

39

47c

MS/WW

Hess

25

Poor

70

Fail

263

7/28/05

26

47c

MS/WW

Hess

45

Fair

70

Fail

Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/ Fail

262

7/27/05

39

47c

MS/WW

No

36

Fair

44

Fail

263

7/28/05

26

47c

MS/WW

No

37

Fair

44

Fail

Overall Assessment:

Community

Assessment Type

Assessment Result

Support Level

Earned IR Category

Actual IR Category

Reason

Benthic Macroinvertebrates

Evaluated

Fail (0/2)

Partial

Fish

Evaluated

Fail (0/2)

Partial

Overall

Evaluated

Fail

Partial

3bc

4a

Assessment is evaluated because samples were not collected in multiple years in the last five year period.

Class BWW2 - Fish kill Assessment:

The 2018 Class BWW2 use assessment based on the four fish kills from 2004-2008 placed this segment in Category 5b. The fish kills were caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the Class BWW2 use was considered impaired. 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. However, because a TMDL was completed for the biological impairment in this stream segment, the fish kill Class BWW2 assessments were placed in Category 4a for the 2008 assessment/listing cycle and remain in Category 4a.

Monitoring and Methods
Assessment Key Dates
7/6/2004
Fish Kill
7/25/2005
Biological Monitoring
7/25/2006
Fish Kill
1/29/2007
Fish Kill
9/15/2008
Fish Kill
7/28/2005
Biological Monitoring
7/27/2005
Biological Monitoring
4/30/2007
TMDL Completed
Methods
120
Surveys of fish and game biologists/other professionals
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