Lower Pine Lake IA 02-IOW-758

Hardin County S4T87NR19W 0.5 mi E of Eldora.

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.

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Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trophic: Hypereutrophic
Trend: Stable
Created: 11/1/2023 8:12:51 AM
Updated: 2/2/2024 10:47:07 AM

Use Support

Class A1

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Moderate

Cycle Added

2006

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Beach monitoring: Iowa DNR WQMA

TMDL Priority

Tier II

Algal Growth: Chlorophyll a

Support Level

Not Supported

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Agriculture

Source Confidence

Moderate

Cycle Added

1998

Impairment Rationale

Narrative criteria violation: aesthetically objectionable conditions

Data Source

Ambient monitoring: Iowa DNR-lakes

Algal Growth: Noxious Aquatic Plants - Algae

Support Level

Not Supported

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Agriculture

Source Confidence

Moderate

Cycle Added

2008

Impairment Rationale

Narrative criteria violation: aesthetically objectionable conditions

Data Source

Biological monitoring: Iowa DNR Fisheries

Class BWW1

Aquatic Life - Warm Water Type 1

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 (monitored) as “not supported” due to high levels of indicator bacteria that exceeded Iowa’s water quality standards and also due to aesthetically objectionable conditions caused by algae blooms. The level of inorganic suspended solids was relatively low and does not suggest water quality problems due to non-algal turbidity. The Class BWW1 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 organic enrichment at Lower Pine Lake was prepared by DNR and approved by EPA in 2002; thus, this lake was placed into IR Category 4a (TMDL approved) for the 2004 assessment/listing cycle. Because the Section 303(d) impairment due to indicator bacteria (aka, "pathogens") was not addressed in the TMDL, this waterbody was moved from IR Category 4a to Category 5a (impaired; TMDL required) for the 2006 assessment/listing cycle and remains in Category 5a for the current assessment/listing cycle.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2020-2022	14000172	LPINELK 1
Iowa DNR	6	WQ	CY 2020-2020	14000362	LPINELK 2
Iowa DNR	6	WQ	CY 2020-2022	21420001	Pine Lake South Beach
Iowa DNR	6	WQ	CY 2018-2022	22420001	Lower Pine Lake
Iowa DNR	6	FT	See Below	1191	Lower Pine Lake	Near Eldora

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

14000172

4/3/4

0 / NA

Evaluated

Full

14000362

4/3/4

0 / NA

Evaluated

Full

21420001

16/15/15

136

109

YES

3 / 4

4 / 4

3 / 4

YES

Mon

Not

22420001

7/3/4

0 / 3

0 / NA

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
22420001	6	21 / 5	7.86	9	8.46	0	5	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
22420001	6	Chlorophyll a TSI	15 / 5	46	81	67	YES	Mon	Not
22420001	6	Secchi TSI	22 / 5	53	83	72	YES	Mon	Not
22420001	6	Total Phosphorus TSI	15 / 5	37	88	70	NA	NA	NA
22420001	6	Fixed suspended solids	15 / 5	0.6	42.7	5	NA	NA	NA

Class BWW1 - 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
22420001	6	Dissolved Oxygen	22 / 5	5	15.4	9.9	0	NA / NA	5	NO	Mon	Full
22420001	6	pH	21 / 5	7.86	9	8.46	0	NA / NA	5	NO	Mon	Full
22420001	6	Temperature	22 / 5	16.6	29.6	23.5	0	NA / NA	5	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
22420001	6	6	20.15931559	73%	3.967483612	34%	NO	Evaluated	NA

Class BWW1 - 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
22420001	6	Ammonia	15 / 5	0.241	0.08	0.04	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)
1191	tissue plug	2017	largemouth bass	3	36.3	0.093
Support Level	Full

Monitoring and Methods

Assessment Key Dates

6/19/2018

Monitoring Start

9/6/2022

Monitoring End

7/12/2017

Fish Tissue Monitoring

5/13/2003

TMDL Completed

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

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