Iowa DNR
Iowa DNR

ADBNet

Water Quality Assessments
Impaired Waters List

Lake Of Three Fires IA 05-PLA-1476

Taylor County S12T68NR34W 2 mi NNE of Bedford.

Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trophic
Hypereutrophic
Trend
Stable
Created
1/3/2022 7:47:22 AM by
Updated
2/17/2022 11:44:14 AM by
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
303(d) Listing Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2004
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
Support Level
Not Supported
Impairment Code
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
Moderate
303(d) Listing Status
Continuing
Source
Agriculture
Source Confidence
Moderate
Cycle Added
2014
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
Moderate
303(d) Listing Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2018
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier IV
Class BLW
Aquatic Life - Lakes and wetlands
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
High
303(d) Listing Status
Continuing
Source
Agriculture
Source Confidence
N/A
Cycle Added
2016
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier IV
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Moderate
303(d) Listing Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2018
Impairment Rationale
Significantly > 10% of samples fail to meet criterion
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier IV
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Slight
303(d) Listing Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
N/A
Cycle Added
2020
Impairment Rationale
Adverse impacts on plant/animal communities
Data Source
Ambient monitoring: Iowa DNR-lakes
Class C
Drinking Water -
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Moderate
303(d) Listing 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 IV
Class HH
Human Health -
Fully Supported
No delistings for this assessment cycle.
Documentation
Assessment Summary

The Class A1 use was assessed (monitored) as “not supported” due to aesthetically objectionable conditions caused by turbidity, aesthetically objectionable conditions caused by algae blooms, and due to frequent violations of the state criterion for pH. The Class BLW use was assessed (monitored) as “not supported" due to violations of the state's criterion for dissolved oxygen and pH. In addition, the Class BLW use was assessed (evaluated) as “WINOFI” due to cyanobacteria blooms. The Class C use was assessed (monitored) as “not supported" due to violations of the state's criterion for pH. The Class HH (fish consumption) use was assessed (monitored) as “fully supported” based on fish tissue sampling data. Note: A TMDL for impacts of siltation and nutrients at Lake of Three Fires was prepared by DNR and approved by EPA in 2002. Additionally, a TMDL for indicator bacteria at Lake of Three Fires was prepared by DNR and approved by EPA in 2010. Because not all Section 303(d) impairments identified for the current assessment/listing cycle (dissolved oxygen and pH) are addressed in the two TMDLs, this lake is placed into IR Category 5a (TMDL needed.)

Assessment Explanation

Data Sources:

Data Source

Data Source ID

Data Type

Data Age

Site ID

Site Name

Site Description

Iowa DNR

6

WQ

CY 2018-2020

21870001

Lake of Three Fires Beach (Lake of Three Fires State Park)

Iowa DNR

6

WQ

CY 2016-2019

22870001

Lake of Three Fires Max Depth

Iowa DNR

6

FT

See Below

158

Lake of Three Fires

Near Bedford

Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2018/ 2019/2020)

2018 Geometric Mean

2019 Geometric Mean

2020 Geometric Mean

Violates Annual Geometric Mean?

# 2018 SSM violations / SSM Violations needed for impairment

# 2019 SSM violations / SSM Violations needed for impairment

# 2020 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

21870001

6

11/15/15

16

11

22

NO

0 / 3

2 / 4

2 / 4

NO

Monitored

Full

Lake of Three Fires was assessed as "not supported" for the 2006 assessment/listing cycle. Based on DNR’s assessment methodology 2 consecutive assessment/listing cycles without violations of the geometric mean criterion and without significantly greater than 10% of the samples violating the single-sample maximum criterion are necessary to propose delisting based on bacteria violations. There were no violations of the geometric mean criterion and there were less than 10% of the samples exceeding the single-sample maximum criterion for the 2020 or current 2022 assessment listing cycles. Therefore, the impairment for indicator bacteria is suggested for delisting (from 4a) for the 2022 assessment/listing cycle.

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

22870001

6

12 / 4

7.5

9.7

8.6

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

22870001

6

Chlorophyll a TSI

12 / 4

35

82

60

NO

Monitored

Full

22870001

6

Secchi TSI

12 / 4

53

73

68

YES

Monitored

Not

22870001

6

Total Phosphorus TSI

12 / 4

54

78

72

NA

NA

NA

22870001

6

Inorganic suspended solids

12 / 4

0.6

7

3.8

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

22870001

6

Ammonia

12 / 4

0.0003

0.228

0.05

NA

0 / 0

4

NO

Monitored

Full

22870001

6

Dissolved Oxygen

12 / 4

3.1

19.3

8.4

3

NA / NA

4

NO

Monitored

Full

22870001

6

pH

12 / 4

7.5

9.7

8.6

4

NA / NA

4

YES

Monitored

Not

22870001

6

Temperature

12 / 4

21.9

30.4

25.2

0

NA / NA

4

NO

Monitored

Full

According to DNR's methodology, a lake must meet water quality standards for two consecutive cycles to suggest de-listing. Therefore, Lake of Three Fires will remain listed for the 2022 cycle as "not supported" its Class BLW uses due to dissolved oxygen.

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

22870001

6

6

44.90

99.3%

28.45

88.0%

YES

Evaluated

3b

Class C - Conventional Parameters:

Site ID

Data Source ID

Parameter Name

# Samples / # Years

Minimum Value

Maximum Value

Mean Value

Median Value

# Violations

Violates Significantly >10% Rule?

Assessment Type

Support Level

22870001

6

Inorganic nitrogen (nitrate and nitrite)

12 / 4

0.02

1.12

0.26

0.03

0

NO

Monitored

Full

22870001

6

pH

12 / 4

7.5

9.7

8.6

9

4

YES

Monitored

Not

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)

158

tissue plug

2019

largemouth bass

10

32.6

0.196

158

tissue plug

2017

largemouth bass

3

41.9

0.28

Support Level

Full

Monitoring and Methods
Assessment Key Dates
6/17/2014
Fixed Monitoring Start Date
8/31/2020
Fixed Monitoring End Date
5/19/2017
Fish Tissue Monitoring
7/1/2019
Fish Tissue Monitoring
1/30/2003
TMDL Completed
4/1/2011
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)
420
Indicator bacteria monitoring