Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Mississippi River IA 01-NEM-61

from Iowa R. (Louisa Co.) to Lock & Dam 15 at Davenport Scott Co.

Cycle
2024
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
11/1/2023 8:13:12 AM
Updated
2/2/2024 10:22:41 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
N/A
Cycle Added
2016
Impairment Rationale
Listing by adjacent state
Data Source
Ambient monitoring: adjacent state
TMDL Priority
Tier IV
Class BWW1
Aquatic Life - Warm Water Type 1
WINOFI
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Slight
Status
Continuing
Source
Natural
Source Confidence
Moderate
Cycle Added
2016
Impairment Rationale
Potential Impairment
Data Source
Fish kill investigation: Iowa DNR
Class HH
Human Health -
Fully Supported
Impairment Delistings
Cycle Added Class Cause Data Source Rationale
2018 Class BWW1 Metals: Aluminum Ambient monitoring: adjacent state New data: WQ improvement (chemical / physical / bacterial)
Documentation
Assessment Summary

The Class A1 use was assessed as "not supported" due to high levels of indicator bacteria (fecal coliforms) reported by the Illinois EPA. The Class BWW1 use was assessed as "WINOFI" due to a fish kill attributed to natural causes. The Class HH use was assessed as "fully supported" based on the results of fish tissue and water quality monitoring data. The results of interstate consultation via the UMRBA Water Quality Task Force were also used to develop this assessment. The water quality monitoring data collected at the IEPA site L-04 were also used to assess segment IA 02-ICM-619.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

IEPA

10

WQ

CY 2020-2022

99990020

Mississippi River

IEPA Site L-04

Iowa DNR

6

FT

See Below

1130

Mississippi River

downstream of Muscatine

Iowa DNR

6

FT

See Below

1168

Mississippi River

at Linwood

Iowa DNR

6

FT

See Below

1359

Mississippi River Pool 16

Montpelier


Class A1 - Indicator Bacteria: No Data

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

99990020

10

11 / 3

7.4

8.3

8

0

3

NO

Mon

Full


Class BWW1 - Binomial 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

99990020

10

Chloride

12 / 3

21.6

41.4

28.6

NA

0 / 0

4

NO

Mon

Full

99990020

10

Dissolved Oxygen

11 / 3

7.4

14.6

11.5

0

NA / NA

3

NO

Mon

Full

99990020

10

pH

11 / 3

7.4

8.3

8

0

NA / NA

3

NO

Mon

Full

99990020

10

Sulfate

12 / 3

15.4

33.3

24.7

0

NA / NA

4

NO

Mon

Full

99990020

10

Temperature

11 / 3

1.8

25.3

11.9

0

NA / NA

3

NO

Mon

Full


Class BWW1 - Toxic Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Maximum Value

Mean Value

Median Value

# Acute / Chronic Violations

>1 Acute / Chronic Violation

Assessment Type

Support Level

99990020

10

Aluminum

12 / 3

1000

372.5

353

0 / 1

NO

Mon

Full

99990020

10

Ammonia

11 / 3

0.14

0.07

0.05

0 / 0

NO

Mon

Full

99990020

10

Arsenic

12 / 3

1.31

0.87

0.94

0 / 0

NO

Mon

Full

99990020

10

Cadmium

12 / 3

1.5

1.5

1.5

0 / 0

NO

Mon

Full

99990020

10

Chromium

12 / 3

2.5

1.9

2.5

0 / 0

NO

Mon

Full

99990020

10

Copper

12 / 3

4.69

2.71

2.5

0 / 0

NO

Mon

Full

99990020

10

Cyanide

12 / 3

1

0.95

1

0 / 0

NO

Mon

Full

99990020

10

Lead

12 / 3

2.5

2.5

2.5

0 / 0

NO

Mon

Full

99990020

10

Nickel

12 / 3

2.5

1.7

1.7

0 / 0

NO

Mon

Full

99990020

10

Selenium

12 / 3

3.5

2.6

2.5

0 / 0

NO

Mon

Full

99990020

10

Silver

12 / 3

1.5

1.5

1.5

0 / 0

NO

Mon

Full

99990020

10

Zinc

12 / 3

5

3.3

2.5

0 / 0

NO

Mon

Full


Class BWW1 - Fish kill Assessment:


The Class BWW1 use assessment based on the 2015 fish kill placed this segment in Category 3b. Because the cause of the fish kill was not identified, or the fish kill was attributed to a non-pollutant cause (e.g., winterkill), the assessment type is “evaluated.” Segments assessed using “evaluated” assessments are placed in Category 3b and are added to the state list of waters in need of further investigation (WINOFI). If no additional fish kills are reported in the segment for a 10-year period (2025), the Category will be changed from 3b to 3a (not assessed).


Details about the 2015 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/918


Class HH-F - Toxic Parameters:

Site ID

Data Source ID

Parameter Name

# Samples per Year (2020/ 2021/2022)

2020 Mean

2021 Mean

2022 Mean

# Non-Detects per Year (2020/2021/2022)

Support Level per Year (2020/2021/2022)

Assessment Type

Support Level

99990020

10

Arsenic

4/4/4

1.635

1.168

1.015

0/0/2

Full/Full/Full

Mon

Full

99990020

10

Cadmium

4/4/4

1.698

0

0

3/4/4

Full/Full/Full

Mon

Full

99990020

10

Chromium

4/4/4

2.325

1.485

1.768

2/1/2

Full/Full/Full

Mon

Full

99990020

10

Chromium

4/4/4

2.325

1.485

1.768

2/1/2

Full/Full/Full

Mon

Full

99990020

10

Copper

4/4/4

2.57

0

3.048

1/4/3

Full/Full/Full

Mon

Full

99990020

10

Cyanide

4/4/4

0

0.84

0

4/3/4

Full/Full/Full

Mon

Full

99990020

10

Nickel

4/4/4

1.928

3.895

2.518

0/2/3

Full/Full/Full

Mon

Full

99990020

10

Selenium

4/4/4

2.758

0

0

3/4/4

Full/Full/Full

Mon

Full

99990020

10

Zinc

4/4/4

6.432

6.425

9.132

2/3/2

Full/Full/Full

Mon

Full


Class HH - Fish Tissue Sampling:

Site ID

Biopart

Year

Species

# in sample / # of samples

Avg Length (cm)

(Avg) Hg (ppm)

Chlordane (ppm)

Sum PCBs (ppm)

1168

whole

2016

common carp

3

43.1

0.05

0.06

0.06

1168

fillet

2018

channel catfish

3

42.7

0.03

0.06

1168

fillet

2018

common carp

3

57.2

0.02

0.08

1130

fillet

2018

channel catfish

3

44.1

0.02

0.07

1130

fillet

2018

common carp

3

64.9

0.02

0.07

1130

fillet

2018

common carp

1

50.4

0.02

0.15

1359

tissue plug

2019

walleye

2

50.3

0.179

1359

tissue plug

2020

bluegill

20

18.6

0.093

1359

tissue plug

2020

crappie spp.

20

29.8

0.132

1359

tissue plug

2020

flathead catfish

3

40.3

0.169

1359

tissue plug

2020

freshwater drum

20

43.3

0.219

1359

tissue plug

2019

largemouth bass

20

32.6

0.176

1359

tissue plug

2020

northern pike

13

63.9

0.14

1359

tissue plug

2020

walleye

14

47.9

0.207

1359

tissue plug

2020

white bass

20

28.9

0.14

1359

tissue plug

2021

northern pike

7

59.2

0.118

1359

tissue plug

2021

flathead catfish

7

52.8

0.142

Support Level

Full



Monitoring and Methods
Assessment Key Dates
7/1/2019
Fish Tissue Monitoring
1/29/2015
Fish Kill
3/3/2020
Monitoring Start
12/15/2022
Monitoring End
7/21/2016
Fish Tissue Monitoring
7/1/2020
Fish Tissue Monitoring
10/29/2018
Fish Tissue Monitoring
6/1/2021
Fish Tissue Monitoring
6/9/2021
Fish Tissue Monitoring
Methods
120
Surveys of fish and game biologists/other professionals
140
Incidence of spills and/or fish kills
200
Physical/Chemical Monitoring
260
Fish tissue analysis
420
Indicator bacteria monitoring
860
Other Agencies/Organizations provided monitoring data