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 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: 8/12/2020 3:15:22 PM
Updated: 10/14/2020 11:39:50 AM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class C

Drinking Water -

Not Assessed

Class HH

Human Health -

Partially Supported

Fish Consumption Advisory: Mercury

Support Level

Partially 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

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use is assessed (monitored) as “fully supported”. The Class BLW use is assessed (monitored) as “fully supported”. The Class C (drinking water) use remains “not assessed” due to a lack of information upon which to base an assessment. Class HH uses are assessed (monitored) as “partially supported” due to the issuance of a fish consumption advisory at this lake.

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 2016-2018	21590001	Red Haw Beach (Red Haw State Park)
Iowa DNR	6	WQ	CY 2014-2018	22590002	Red Haw Lake
Iowa DNR		FT	See Below	99	Red Haw 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
21590001	6	30 / 3	11.08	9.76	14.4	No	1	3%	NO	Monitored	Full

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
22590002	6	15 / 5	9.1	8.3	8.4	1	7%	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	70	58	NO	Monitored	Full
22590002	6	Secchi TSI	15 / 5	46	65	60	NO	Monitored	Full
22590002	6	Total Phosphorus TSI	15 / 5	51	67	60	NA	NA	NA
22590002	6	Inorganic suspended solids	15 / 5	0.3	5.24	1.5	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
22590002	6	Ammonia	15 / 5	0.046	0.01	0.01	0 / 0	0% / 0%	NO	Monitored	Full
22590002	6	Dissolved oxygen	15 / 5	12.69	8.75	8.3	NA / 0	NA / 0%	NO	Monitored	Full
22590002	6	pH	15 / 5	9.1	8.3	8.4	1 / NA	7% / NA	NO	Monitored	Full
22590002	6	Temperature	15 / 5	29.8	24.4	25.4	0 / 0	0% / 0%	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 Wet Mass = 75th Percentile	Assessment Type	Support Level
22590002	6	11	92.642	98.5 %	4.367	76.6 %	NO	Evaluated	NA

Class C - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
22590002	6	Inorganic nitrogen (nitrate and nitrite)	15 / 5	0.035	0.027	0.03	0	0%	NO	Monitored	Full

The Class C uses are not assessed due to the lack of data sufficient for developing a valid assessment of support of the Class C uses.

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

8/15/07

largemouth bass

Fillet

0.516

Yes

Evaluated

Partial

8/18/08

largemouth bass

Fillet

0.428

Yes

Evaluated

Partial

8/28/12

largemouth bass

plug

0.409

Yes

Evaluated

Partial

Monitoring and Methods

Assessment Key Dates

5/27/2014

Fixed Monitoring Start Date

8/29/2018

Fixed Monitoring End Date

8/18/2008

Fish Tissue Monitoring

8/28/2012

Fish Tissue Monitoring

8/15/2007

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