Chariton River IA 05-CHA-1308

from the Highway 2 crossing (S27 T69N R17W Appanoose Co.) to Rathbun Dam in S35 T69N R18W Appanoose Co.

Assessment Cycle

2020

Release Status

Final

Data Collection Period

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.

Overall IR Category: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Stable

Created: 6/12/2020 8:02:35 AM
Updated: 10/15/2020 11:39:43 AM

Assessment conducted in accordance with Iowa's 2020 IR methodology

Use Support

Class A1

Recreation

Primary contact

Partially Supported

Impairments

Support Level

Partially Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: Iowa DNR-rivers

TMDL Priority

Tier III

Class BWW1

Aquatic Life

Warm Water Type 1

WINOFI

Further Investigation Needed

Support Level

Water in Need of Further Investigation (WINOFI)

Impairment Code

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

Cause Magnitude

Slight

Status

New

Source

Hydromodification: Dam Release

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Non Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

Class C

Drinking Water

Fully Supported

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 use was assessed as "partially supported" based on levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "partially supported" due to a fish kill investigation. The Class C use was assessed as "fully supported" based on water quality monitoring data. The Class HH use was assessed as "fully supported" based on fish tissue sampling and water quality monitoring data.

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	10040002	Chariton River at 461st St.
USACE	12	WQ	CY 2016-2018	99990007	Rathbun Reservoir Outlet (Site RA-28)
Iowa DNR	6	BIO	See Below	914	Chariton River	Rathbun - at 461st St. Bridge
Iowa DNR	6	FT	See Below	148	Chariton River	N of Centerville

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
10040002	6	21 / 3	173.48	31.85	67.19	Yes	4	19%	Yes	Monitored	Partial

Class A - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
10040002	6	36 / 3	8.1	7.7	7.7	0	0%	No	Monitored	Full
99990007	12	5 / 2	7.83	7.7	7.73	0	0%	No	Evaluated	Full

Class BWW1 - 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
10040002	6	Ammonia	36 / 3	0.37	0.07	0.02	0 / 0	0% / 0%	No	Monitored	Full
10040002	6	Chloride	36 / 3	33	9.3	8.8	0 / 0	0% / 0%	No	Monitored	Full
10040002	6	Dissolved oxygen	36 / 3	15	9.6	9.8	NA / 0	NA / 0%	No	Monitored	Full
10040002	6	pH	36 / 3	8.1	7.7	7.7	0 / NA	0% / NA	No	Monitored	Full
99990007	12	pH	5 / 2	7.83	7.7	7.73	0 / NA	0% / NA	No	Evaluated	Full
10040002	6	Sulfate	36 / 3	22	19	20	0 / NA	0% / NA	No	Monitored	Full
10040002	6	Temperature	36 / 3	26.5	13	12.7	0 / 0	0% / 0%	No	Monitored	Full
99990007	12	Temperature	17 / 3	26.8	20.6	20.3	0 / 0	0% / 0%	No	Monitored	Full

Class BWW1 - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Acute / Chronic Violations	% Acute/ Chronic Violations	>1 Acute / Chronic Violation	Assessment Type	Support Level
10040002	6	Aluminum	9 / 2	1.3	0.6	0.5	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Arsenic	9 / 2	2.6	1.8	1.9	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Cadmium	9 / 2	0.025	0.025	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Chromium	9 / 2	0.63	0.46	0.43	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Copper	9 / 2	1.3	1.08	1.2	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Lead	9 / 2	0.09	0.047	0.025	0 / 0	0% / 0%	No	Evaluated	Full
99990007	12	Lead	1 / 1	1730	1730	1730	1 / 1	100% / 100%	NA	Evaluated	NA
99990007	12	Mercury	1 / 1	9.7	9.7	9.7	1 / 1	100% / 100%	NA	Evaluated	NA
10040002	6	Nickel	9 / 2	2.6	2.1	2	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Selenium	9 / 2	1.5	0.53	0.52	0 / 0	0% / 0%	No	Evaluated	Full
99990007	12	Selenium	1 / 1	0.4	0.4	0.4	0 / 0	0% / 0%	No	Evaluated	Full
10040002	6	Zinc	9 / 2	3.1	0.87	0.49	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/Thermal	BM Sample Gear	BMIBI score	BMIBI Class	40a BMIBI BIT	BMIBI Pass/ Fail
914	7/20/18	550	40a	MO/WW	Hess	63	Good	41	Pass
914	8/1/16	550	40a	MO/WW	Hess	53	Fair	41	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (2/2)	Full	1	1	Assessment is evaluated because the drainage area of the sample site was larger than the calibrated range.

Class BWW1 – Fish kill Assessment:

The Class BWW1 use assessment based on the 2018 fish kill placed this segment in Category 3b. Because the cause of the fish kill was not identified, or

the fish kill was attributed to a non-pollutant cause (e.g., winterkill), the assessment type is “evaluated.” Segments assessed using “evaluated” assessments

are placed in Category 3b and are added to the state list of waters in need of further investigation. If no additional fish kills are reported in the segment for

a 10 year period (2028), the Category will be changed from 3b to 3a (water not assessed).

Details about the 2018 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/952

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
10040002	6	Chloride	36 / 3	33	9.3	8.8	0	0%	No	Monitored	Full
10040002	6	Inorganic nitrogen (nitrate and nitrite)	36 / 3	0.92	0.32	0.19	0	0%	No	Monitored	Full

Class C - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	Number of Non - Detects	Mean Value > Criterion or MCL	Assessment Type	Support Level
10040002	6	Alachlor	3 / 1	0.05	0.05	0.05	3	No	Evaluated	Full
99990007	12	Alachlor	1 / 1	0.01	0.01	0.01	1	No	Evaluated	Full
10040002	6	Atrazine	3 / 1	0.6	0.5	0.5	0	No	Evaluated	Full
99990007	12	Atrazine	9 / 3	0.96	0.5	0.52	0	No	Evaluated	Full
10040002	6	Cadmium	9 / 2	0.025	0.025	0.025	9	No	Evaluated	Full
10040002	6	Chromium	9 / 2	0.63	0.46	0.43	0	No	Evaluated	Full
99990007	12	Glyphosate	1 / 1	0.1	0.1	0.1	1	No	Evaluated	Full
10040002	6	Lead	9 / 2	0.09	0.047	0.025	5	No	Evaluated	Full
99990007	12	Lead	1 / 1	1730	1730	1730	0	NA	Evaluated	NA
10040002	6	Silver	9 / 2	0.025	0.025	0.025	9	No	Evaluated	Full
10040002	6	Simazine	3 / 1	0.05	0.05	0.05	3	No	Evaluated	Full

Class HH-FW - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	Number of Non - Detects	Mean Value > Criterion or MCL	Assessment Type	Support Level
10040002	6	Copper	9 / 2	1.3	1.08	1.2	0	No	Evaluated	Full
99990007	12	Copper	1 / 1	4	4	4	1	No	Evaluated	Full
99990007	12	Mercury	1 / 1	9.7	9.7	9.7	0	NA	Evaluated	NA
10040002	6	Nickel	9 / 2	2.6	2.1	2	0	No	Evaluated	Full
10040002	6	Selenium	9 / 2	1.5	0.53	0.52	4	No	Evaluated	Full
99990007	12	Selenium	1 / 1	0.4	0.4	0.4	1	No	Evaluated	Full
10040002	6	Zinc	9 / 2	3.1	0.87	0.49	0	No	Evaluated	Full

Class HH – Fish Tissue Sampling:

Site ID	Date	Species Name	Biopart	# in sample	Hg result	Hg violation (>0.3)?	Assessment Type	Support Level
148	7/31/2013	white crappie	plug	5	0.195	No	Evaluated	Full
148	8/19/2011	white crappie	plug	5	0.316	Yes	Evaluated	Partial

Monitoring and Methods

Assessment Key Dates

1/11/2016

Fixed Monitoring Start Date

12/4/2018

Fixed Monitoring End Date

7/31/2013

Fish Tissue Monitoring

8/19/2011

Fish Tissue Monitoring

8/1/2016

Biological Monitoring

3/4/2018

Fish Kill

7/20/2018

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

230

Fixed station physical/chemical (conventional plus toxic pollutants)

260

Fish tissue analysis

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring