Red Haw Lake IA 04-LDM-1073

Lucas County S28T71NR21W 2 mi SE of Chariton.

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 2018 - 2020
Stream/River Water Quality Data	CY 2018 - 2020
Lake Water Quality Data	CY 2016 - 2020
Biological Sampling Data	CY 2016 - 2020*
Fish Kill Data	CY 2016 - 2020
Fish Tissue Sampling Data	CY 2016 - 2020
Continuous Dissolved Oxygen Sampling Data	CY 2016 - 2020
*Biological sites sampled in both 2015 and 2019 were also assessed.

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Cycle: 2022
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trophic: Eutrophic
Trend: Stable
Created: 12/28/2021 10:06:22 AM
Updated: 1/5/2022 1:11:52 PM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class C

Drinking Water -

Fully Supported

Class HH

Human Health -

Not Supported

Fish Consumption Advisory: Mercury

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Atmospheric Deposition

Source Confidence

Low

Cycle Added

2008

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 “fully supported”. The Class BLW use was assessed (monitored) as “fully supported”. The Class C use was assessed (monitored) as “fully supported”. The Class HH (fish consumption) use was assessed as “not supported” based on fish tissue sampling data and due to the existence of a one meal per week mercury fish consumption advisory for this lake.

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	21590001	Red Haw Beach (Red Haw State Park)
Iowa DNR	6	WQ	CY 2016-2020	22590002	Red Haw Lake
Iowa DNR	6	FT	See Below	99	Red Haw Lake	ESE of Chariton

Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2018/ 2019/2020)

2018 Geometric Mean

2019 Geometric Mean

2020 Geometric Mean

Violates Annual Geometric Mean?

# 2018 SSM violations / SSM Violations needed for impairment

# 2019 SSM violations / SSM Violations needed for impairment

# 2020 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

21590001

5/8/9

0 / NA

0 / 3

1 / 3

Monitored

Full

22590002

3/3/3

0 / NA

Evaluated

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
22590002	6	15 / 5	7.2	8.7	7.9	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
22590002	6	Chlorophyll a TSI	15 / 5	31	69	50	NO	Monitored	Full
22590002	6	Secchi TSI	15 / 5	46	70	60	NO	Monitored	Full
22590002	6	Total Phosphorus TSI	15 / 5	51	86	58	NA	NA	NA
22590002	6	Inorganic suspended solids	15 / 5	0.3	10.4	1.7	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
22590002	6	Ammonia	15 / 5	0.0003	0.1537	0.03	NA	0 / 0	4	NO	Monitored	Full
22590002	6	Dissolved Oxygen	14 / 5	3.8	10.1	7.6	2	NA / NA	4	NO	Monitored	Full
22590002	6	pH	15 / 5	7.2	8.7	7.9	0	NA / NA	4	NO	Monitored	Full
22590002	6	Temperature	15 / 5	16.8	29.5	23.8	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
22590002	6	6	4.37	88.3%	2.74	33.6%	NO	Evaluated	NA

Class C - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	Median Value	# Violations	Violates Significantly >10% Rule?	Assessment Type	Support Level
22590002	6	Inorganic nitrogen (nitrate and nitrite)	15 / 5	0.02	0.04	0.02	0.02	0	NO	Monitored	Full
22590002	6	pH	15 / 5	7.2	8.7	7.9	7.9	0	NO	Monitored	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)
99	tissue plug	2012	largemouth bass	5	32.86	0.409
Support Level	Not	A one meal/week mercury consumption advisory for largemouth bass 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

5/23/2016

Fixed Monitoring Start Date

9/9/2020

Fixed Monitoring End Date

8/28/2012

Fish Tissue Monitoring

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