Kent Park Lake IA 02-IOW-694

Johnson County S24T80NR8W 2.5 mi. W of Tiffin.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
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Cycle: 2024
Release Status: Final
Overall IR: 1 - All designated uses are met.
Trophic: Eutrophic
Trend: Stable
Created: 11/1/2023 8:12:48 AM
Updated: 2/2/2024 2:17:37 PM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class HH

Human Health -

Fully Supported

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use was assessed as “fully supported.” The Class BLW use was assessed as “fully supported.” The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data. Note: A TMDL for the algae and pH impairments at Kent Park Lake was prepared by Iowa DNR and was approved by U.S.EPA in June 2015.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2020-2020	21520002	F.W. Kent Park Beach
Iowa DNR	6	WQ	CY 2019-2022	22520005	Kent Park Lake
Iowa DNR	6	FT	See Below	1304	Kent Park Lake	Kent Park NW of Tiffin

Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2020/ 2021/2022)

2020 Geometric Mean

2021 Geometric Mean

2022 Geometric Mean

Violates Annual Geometric Mean?

# 2020 SSM violations / SSM Violations needed for impairment

# 2021 SSM violations / SSM Violations needed for impairment

# 2022 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

21520002

12/0/0

1 / 4

Mon

Full

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
22520005	6	12 / 4	7.9	8.9	8.3	0	4	NO	Mon	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
22520005	6	Chlorophyll a TSI	12 / 4	26	61	50	NO	Mon	Full
22520005	6	Secchi TSI	12 / 4	40	66	57	NO	Mon	Full
22520005	6	Total Phosphorus TSI	12 / 4	35	62	54	NA	NA	NA
22520005	6	Fixed suspended solids	12 / 4	0.6	7	1.7	NA	NA	NA

DNR's assessment methodology indicates that a TSI value less than or equal to 63 is necessary to suggest de-listing of an impairment. The chlorophyll a TSI value for the 2010 assessment listing cycle was 65, which based on DNR's assessment/listing methodology indicated an impairment based on the narrative criteria protecting against aesthetically objectionable conditions. Because the TSI value for the 2024 assessment/listing cycle is less than or equal to the delisting threshold of 63 (median TSI value for chlorophyll a was 50), based on DNR's methodology, these values suggest "full support" of the Class A1 uses protecting against aesthetically objectionable conditions and the impairment (5a) for chlorophyll a is suggested for delisting for the 2024 assessment/listing cycle.

Class BLW - 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
22520005	6	Dissolved Oxygen	12 / 4	5.7	15.1	9.1	0	NA / NA	4	NO	Mon	Full
22520005	6	pH	12 / 4	7.9	8.9	8.3	0	NA / NA	4	NO	Mon	Full
22520005	6	Temperature	12 / 4	18.9	28.2	24.5	0	NA / NA	4	NO	Mon	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
22520005	6	3	14.37540528	96%	2.571630774	58%	NO	Evaluated	NA

Class BLW - 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
22520005	6	Ammonia	12 / 4	0.06	0.01	0.01	0 / 0	NO	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)
1304	fillet	2013	channel catfish	3	47.8	0.05	<0.2	<0.6
1304	tissue plug	2013	largemouth bass	5	31.7	0.107
Support Level	Full

Monitoring and Methods

Assessment Key Dates

6/17/2019

Monitoring Start

9/27/2022

Monitoring End

8/9/2013

Fish Tissue Monitoring

6/26/2015

TMDL Completed

Methods

150

Monitoring data more than 5 years old

200

Physical/Chemical Monitoring

260

Fish tissue analysis

340

Primary producer surveys (phytoplankton/periphyton/macrophyton)

420

Indicator bacteria monitoring