Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Maquoketa River IA 01-MAQ-19

upper end of Quaker Mill Pond to Forestville Dam at Backbone Lake (SE 1/4 S15 T90N R6W Delaware Co.).

Cycle
2020
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Improving
Trend Comment
Monitoring data from 2012-2014 suggest a significant (order of magnitude) decline in levels of indicator bacteria compared to levels in the mid-2000s.
Created
8/13/2020 10:02:47 AM
Updated
11/23/2020 3:56:00 PM
Use Support
Class A1
Recreation - Primary contact
Partially Supported
Support Level
Partially Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2010
Impairment Rationale
Geometric mean criterion exceeded
Data Source
Special project/study
TMDL Priority
Tier III
Class BWW1
Aquatic Life - Warm Water Type 1
Fully Supported
Class HH
Human Health -
Not Assessed
General Use
General Use water -
Not Assessed
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 use was assessed as “partially supported” due to levels of indicator bacteria (E.coli) that slightly exceeded state water quality criteria. The Class BWW1 use was assessed as “fully supported” based on biological sampling data. All other designated uses were "not assessed".

Assessment Explanation

Sources of Data:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2012-2013

15280002

Maquoketa River

Mid Maquoketa

Iowa DNR

6

BIO

See Below

1014

Maquoketa River

N of Manchester - MQ006

Iowa DNR

6

BIO

See Below

1039

Maquoketa River

N of Manchester - MQ004


Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples / # Years

2012 Geometric Mean

2013 Geometric Mean

Annual Geometric Mean Violation

# Violations

% Violations

Significantly >10% Violations

Assessment Type

Support Level

15280002

6

14 / 2

123

154

Yes

2

14%

No

Evaluated

Partial


Class BWW1 - Biological Sampling:

Fish:

BioNet Site ID

Date

Drainage Area (mi2)

Ecoregion

Major Drainage/Thermal

Riffle Stream?

FIBI score

FIBI Class

47c FIBI BIT

FIBI Pass/ Fail

1014

8/2/18

153

47c

MS/WW

Und

68

Good

44

Pass

1039

8/1/18

153

47c

MS/WW

Und

77

Excellent

44

Pass

1014

8/23/17

153

47c

MS/WW

Und

73

Excellent

44

Pass

1039

8/22/17

153

47c

MS/WW

Und

77

Excellent

44

Pass

1014

7/22/16

153

47c

MS/WW

Und

63

Good

44

Pass

1039

7/21/16

153

47c

MS/WW

Und

60

Good

44

Pass

1014

7/29/15

153

47c

MS/WW

Und

65

Good

44

Pass

1039

7/27/15

153

47c

MS/WW

Und

61

Good

44

Pass

1014

8/12/14

153

47c

MS/WW

Und

64

Good

44

Pass

1039

8/11/14

153

47c

MS/WW

Und

71

Excellent

44

Pass

Overall Assessment:

Community

Assessment Type

Assessment Result

Support Level

Earned IR Category

Actual IR Category

Reason

Fish

Monitored

Pass (10/10)

Full

1

1

Assessment is monitored because there were five or more FIBI samples collected in the last five years.



Class HH - No Data



Monitoring and Methods
Assessment Key Dates
5/7/2012
Fixed Monitoring Start Date
11/18/2013
Fixed Monitoring End Date
7/22/2016
Biological Monitoring
7/21/2016
Biological Monitoring
8/11/2014
Biological Monitoring
8/12/2014
Biological Monitoring
7/27/2015
Biological Monitoring
7/29/2015
Biological Monitoring
8/22/2017
Biological Monitoring
8/23/2017
Biological Monitoring
8/1/2018
Biological Monitoring
8/2/2018
Biological Monitoring
Methods
315
Regional reference site approach
330
Fish surveys
420
Indicator bacteria monitoring