Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

McKinley Lake IA 05-PLA-1470

Union County S11T72NR31W at W edge of Creston.

Cycle
2022
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trophic
Eutrophic
Trend
Unknown
Created
12/30/2021 4:13:59 PM
Updated
1/6/2022 7:58:41 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
New
Source
Multiple Sources
Source Confidence
Moderate
Cycle Added
2022
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier I
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Moderate
Status
New
Source
Other: Sediment Resuspension
Source Confidence
Moderate
Cycle Added
2022
Impairment Rationale
Narrative criteria violation: aesthetically objectionable conditions
Data Source
Ambient monitoring: Iowa DNR-lakes
TMDL Priority
Tier I
Class BLW
Aquatic Life - Lakes and wetlands
Not Assessed
Class HH
Human Health -
Not Supported
Support Level
Not Supported
Impairment Code
5a - Pollutant-caused impairment. TMDL needed.
Cause Magnitude
Slight
Status
Continuing
Source
Unknown: Source Unknown
Source Confidence
Low
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 aesthetically objectionable conditions caused by poor water transparency and nuisance blooms of algae. The Class HH (fish consumption) use remains assessed (evaluated) as "not supported" (IR 5a) based on fish tissue sampling data and due to the existence of a one meal/week PCBs consumption advisory for channel catfish on this segment. All other designated uses were “not assessed.”

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

14000244

McKinley Lake

Iowa DNR

6

FT

See Below

262

McKinley Lake

Near Creston

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

14000244

6

9 / 3

7.8

9.6

8.8

2

3

NO

Evaluated

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

14000244

6

Chlorophyll a TSI

9 / 3

54

85

66

YES

Monitored

Not

14000244

6

Secchi TSI

9 / 3

73

83

77

YES

Monitored

Not

14000244

6

Total Phosphorus TSI

9 / 3

75

93

83

NA

NA

NA

14000244

6

Inorganic suspended solids

9 / 3

2

43

17

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

14000244

6

Ammonia

9 / 3

0.001

0.598

0.15

NA

0 / 0

3

NO

Evaluated

Full

14000244

6

Dissolved Oxygen

9 / 3

4.9

13.7

8.4

1

NA / NA

3

NO

Evaluated

Full

14000244

6

pH

9 / 3

7.8

9.6

8.8

2

NA / NA

3

NO

Evaluated

Full

14000244

6

Temperature

9 / 3

16.5

29.1

24.9

0

NA / NA

3

NO

Evaluated

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)

262

fillet

2015

common carp

5

53.2

0.09

0.07

0.49

Support Level

Not

A one meal/week PCBs consumption advisory for channel catfish 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
6/26/2015
Fish Tissue Monitoring
5/21/2018
Fixed Monitoring Start Date
8/24/2020
Fixed Monitoring End Date
Methods
220
Non-fixed station physical/chemical monitoring (conventional pollutant only)
260
Fish tissue analysis