Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Five Island Lake IA 04-UDM-1300

Palo Alto County S18T96NR32W at Emmetsburg.

Cycle
2022
Release Status
Final
Overall IR
4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trophic
Hypereutrophic
Trend
Stable
Created
12/30/2021 10:56:21 AM
Updated
1/6/2022 6:55:17 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
Natural: Internal Nutrient Recycling (Primarily Lakes)
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
4a - Pollutant-caused impairment. TMDL has been completed.
Cause Magnitude
High
Status
Continuing
Source
Other: Sediment Resuspension
Source Confidence
High
Cycle Added
2004
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
Class BLW
Aquatic Life - Lakes and wetlands
WINOFI
Impairment Code
3b - Use potentially impaired based on an evaluated assessment.
Cause Magnitude
Moderate
Status
Continuing
Source
Natural: Internal Nutrient Recycling (Primarily Lakes)
Source Confidence
Low
Cycle Added
2016
Impairment Rationale
Adverse impacts on plant/animal communities
Data Source
Ambient monitoring: Iowa DNR-lakes
Class HH
Human Health -
Fully Supported
Impairment Delistings
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 poor water transparency due to both non-algal turbidity and algae. The Class BLW use was assessed (evaluated) as "WINOFI” due to a large population of cyanobacteria. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data. Note: A TMDL for algae and turbidity at Five Island Lake was prepared by DNR and approved by EPA in 2006. Because all Section 303(d) impairments identified for the current assessment/listing cycle (algal growth and turbidity) are addressed by the TMDL, this waterbody remains in IR Category 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

WQ

CY 2016-2019

22740001

Five Island Lake

Iowa DNR

6

FT

See Below

190

Five Island Lake

at Emmetsburg

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

22740001

6

12 / 4

8

8.8

8.4

0

4

NO

Monitored

Full

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

22740001

6

Chlorophyll a TSI

12 / 4

36

75

66

YES

Monitored

Not

22740001

6

Secchi TSI

12 / 4

49

83

73

YES

Monitored

Not

22740001

6

Total Phosphorus TSI

12 / 4

54

81

71

NA

NA

NA

22740001

6

Inorganic suspended solids

12 / 4

0.4

23.5

6.7

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

22740001

6

Ammonia

12 / 4

0.0003

0.175

0.04

NA

0 / 0

4

NO

Monitored

Full

22740001

6

Dissolved Oxygen

12 / 4

5

10.85

8.86

0

NA / NA

4

NO

Monitored

Full

22740001

6

pH

12 / 4

8

8.8

8.4

0

NA / NA

4

NO

Monitored

Full

22740001

6

Temperature

12 / 4

16

28.3

23

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

22740001

6

6

153.19

99.4%

39.10

94.7%

YES

Evaluated

3b

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)

190

fillet

2012

channel catfish

5

43

0.022

0.03

0.09

190

tissue plug

2012

walleye

5

37.1

0.037

Support Level

Full

Monitoring and Methods
Assessment Key Dates
5/31/2016
Fixed Monitoring Start Date
9/4/2019
Fixed Monitoring End Date
10/1/2012
Fish Tissue Monitoring
7/27/2012
Fish Tissue Monitoring
9/29/2006
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)