Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Lake Miami IA 04-LDM-1016

Monroe County S20T73NR17W 5 mi. SE of Lovilia.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trophic
Hypereutrophic
Trend
Stable
Created
12/27/2021 2:43:13 PM
Updated
1/5/2022 11:46:41 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
Moderate
Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2002
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
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: Iowa DNR-lakes
TMDL Priority
Tier I
Class BLW
Aquatic Life - Lakes and wetlands
Not Supported
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
Moderate
Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2002
Impairment Rationale
Adverse impacts on plant/animal communities
Data Source
Biological monitoring: Iowa DNR Fisheries
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: Iowa DNR-lakes
TMDL Priority
Tier I
Class HH
Human Health -
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
High
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Moderate
Cycle Added
2012
Impairment Rationale
Fish consumption advisory in effect: no more than 1 meal/week
Data Source
Fish contaminant monitoring: Iowa DNR
TMDL Priority
Tier IV
Impairment Delistings
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 use was assessed (monitored) as “not supported” due to poor water clarity caused by non-algal turbidity (IR 4a) and violations of the Class A1 standard for pH (IR 5a). The Class BLW use was assessed as “not supported” (IR 4a) due to reduced water transparency related to the presence of common carp populations, sedimentation problems in the lake, and violations of the Class BLW standard for pH (IR 5a). The Class HH (fish consumption) use remains assessed (monitored) as “not supported” (IR 5a) based on the results of fish tissue monitoring and the existence of a one meal per week consumption advisory for mercury in this lake. Note: A TMDL for siltation and nutrients at Lake Miami was prepared by DNR and approved by EPA in 2001. Because the Section 303(d) impairment for pH and mercury in fish tissue was not addressed by the TMDL, this waterbody was placed in IR Category 5a (impaired; TMDL needed) for the current assessment/listing cycle.

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2016-2020

22680001

Lake Miami Max Depth

Iowa DNR

6

FT

See Below

141

Lake Miami

ESE of Lovilia

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

22680001

6

15 / 5

7.5

9.6

8.5

4

4

YES

Monitored

Not

Class A1 - Lake TSI's:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Median Value

Median TSI Violation?

Assessment Type

Support Level

22680001

6

Chlorophyll a TSI

15 / 5

36

82

61

NO

Monitored

Full

22680001

6

Secchi TSI

15 / 5

39

81

73

YES

Monitored

Not

22680001

6

Total Phosphorus TSI

15 / 5

55

85

74

NA

NA

NA

22680001

6

Inorganic suspended solids

15 / 5

0.6

15

3.1

NA

NA

NA

Class BLW - 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

22680001

6

Ammonia

15 / 5

0.0003

0.492

0.09

NA

0 / 0

4

NO

Monitored

Full

22680001

6

Dissolved Oxygen

14 / 5

3.6

21.3

10.1

1

NA / NA

4

NO

Monitored

Full

22680001

6

pH

15 / 5

7.5

9.6

8.5

4

NA / NA

4

YES

Monitored

Not

22680001

6

Temperature

15 / 5

18.2

29.9

24.9

0

NA / NA

4

NO

Monitored

Full

Class BLW - Lake Planktonic Cyanobacteria:

Site ID

Data Source ID

# Samples

Maximum Cyanobacteria Wet Mass

Maximum Cyanobacteria % Composition

Median Cyanobacteria Wet Mass

Median Cyanobacteria % Composition

Median Cyanobacteria Concentration = 75th Percentile

Assessment Type

Support Level

22680001

6

6

72.11

98.0%

14.55

81.0%

NO

Evaluated

NA

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)

141

fillet

2010

largemouth bass

5

NA

0.394

141

fillet

2009

largemouth bass

4

NA

0.353

Support Level

Not

A one meal/week mercury consumption advisory for largemouth bass exists on this segment. Based on IR Methodology, the Class HH (fish consumption) use was assessed as “not supported.”

Monitoring and Methods
Assessment Key Dates
5/25/2016
Fixed Monitoring Start Date
9/9/2020
Fixed Monitoring End Date
10/26/2009
Fish Tissue Monitoring
7/27/2010
Fish Tissue Monitoring
1/28/2002
TMDL Completed
Methods
120
Surveys of fish and game biologists/other professionals
222
Non-fixed-station monitoring (conventional during key seasons and flows)
260
Fish tissue analysis
340
Primary producer surveys (phytoplankton/periphyton/macrophyton)