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 2016 - 2018
Stream/River Water Quality Data	CY 2016 - 2018
Lake Water Quality Data	CY 2014 - 2018
Biological Sampling Data	CY 2014 - 2018*
Fish Kill Data	CY 2014 - 2018
Fish Tissue Sampling Data	CY 2014 - 2018
Continuous Dissolved Oxygen Sampling Data	CY 2014 - 2018
*Biological sites sampled in both 2013 and 2017 were also assessed.

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Cycle: 2020
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trophic: Eutrophic
Trend: Stable
Created: 7/24/2020 1:57:53 PM
Updated: 10/14/2020 9:46:24 AM

Use Support

Class A1

Recreation - Primary contact

Partially Supported

Algal Growth: Chlorophyll a

Support Level

Partially Supported

Impairment Code

4a - Pollutant-caused impairment. TMDL has been completed.

Cause Magnitude

Moderate

Status

Continuing

Source

Agriculture

Source Confidence

Low

Cycle Added

2010

Impairment Rationale

Narrative criteria violation: aesthetically objectionable conditions

Data Source

Ambient monitoring: Iowa DNR-lakes

Bacteria: Indicator Bacteria- E. coli

Support Level

Partially Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Multiple Sources

Source Confidence

N/A

Cycle Added

2014

Impairment Rationale

Single-sample maximum criterion exceeded in significantly > 10% of samples

Data Source

Beach monitoring: Iowa DNR city/county

TMDL Priority

Tier II

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

New

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Significantly > 10% of samples fail to meet criterion

Data Source

Ambient monitoring: Iowa DNR-lakes

Class BLW

Aquatic Life - Lakes and wetlands

WINOFI

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

New

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Significantly > 10% of samples fail to meet criterion

Data Source

Ambient monitoring: Iowa DNR-lakes

Organic Enrichment: Low Dissolved Oxygen

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

New

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Significantly > 10% of samples fail to meet criterion

Data Source

Ambient monitoring: Iowa DNR-lakes

Class HH

Human Health -

Fully Supported

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 uses are assessed (monitored) as “partially supported” due to violations of Iowa’s water quality criterion for indicator bacteria and due to high levels of algae that violate Iowa's narrative criteria protecting against aesthetically objectionable conditions. The level of inorganic suspended solids was low at Kent Park Lake, and does not suggest water quality problems due to non-algal turbidity. Additionally, the Class A1 uses are assessed (evaluated) as "partially supported" due to violations of the criterion for pH The Class BLW uses are assessed (evaluated) as “partially supported” due to due to violations of the criterion for pH and Dissolved Oxygen. Class HH uses are assessed as "fully supporting" based on fish tissue monitoring. 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. Not all of the section 303(d) impairments identified for the current (2018) assessment/listing cycle (indicator bacteria), however, are addressed in the TMDL. Thus, this waterbody remains in Category 5a (impaired; TMDL required) for this assessment/listing cycle.

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2016-2016	21520002	F. W. Kent Park Beach
Iowa DNR	6	WQ	CY 2014-2016	22520005	Kent Park Lake
Iowa DNR		FT	See Below	306	Kent Park Lake

Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2016 Geometric Mean	2017 Geometric Mean	2018 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
21520002	6	14 / 1	20.37	NA	NA	NO	2	14%	NO	Monitored	Full

According to DNR's methodology, a lake must meet water quality standards for two consecutive cycles to suggest de-listing. Therefore, Kent Park Lake will remain listed for the 2020 cycle as "partially supported" its Class A1 uses due to indicator bacteria.

Class A1 - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
22520005	6	9 / 3	9.22	8.63	8.7	1	11%	YES	Evaluated	Partial

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	9 / 3	63	75	69	YES	Monitored	Not
22520005	6	Secchi TSI	9 / 3	63	77	67	YES	Monitored	Not
22520005	6	Total Phosphorus TSI	9 / 3	64	79	70	NA	NA	NA
22520005	6	Inorganic suspended solids	9 / 3	0.7	3.2	1.6	NA	NA	NA

Class BLW - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Acute / Chronic Violations	% Acute/ Chronic Violations	Significantly >10% Violations	Assessment Type	Support Level
22520005	6	Ammonia	9 / 3	0.283	0.06	0.02	0 / 0	0% / 0%	NO	Evaluated	Full
22520005	6	Dissolved oxygen	9 / 3	12.58	10.03	11.3	NA / 1	NA / 11%	YES	Evaluated	Partial
22520005	6	pH	9 / 3	9.22	8.63	8.7	1 / NA	11% / NA	YES	Evaluated	Partial
22520005	6	Temperature	9 / 3	28.3	24.34	25.62	0 / 0	0% / 0%	NO	Evaluated	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 Wet Mass = 75th Percentile	Assessment Type	Support Level
22520005	6	9	133.373	99 %	21.536	93.5 %	NO	Evaluated	NA

Class HH – Fish Tissue Sampling

Site ID

Date

Species Name

Biopart

# in sample

chlordane result

chlordane violation?

PCBs result

PCBs violation?

Hg result

Hg violation?

Assessment Type

Support Level

306

8/9/13

channel catfish

fillet

<0.2

<0.6

<0.05

Evaluated

Full

306

8/9/13

largemouth bass

plug

0.107

Evaluated

Full

Monitoring and Methods

Assessment Key Dates

6/23/2014

Fixed Monitoring Start Date

9/18/2016

Fixed Monitoring End Date

8/9/2013

Fish Tissue Monitoring

6/26/2015

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