Iowa River IA 02-IOW-622

from south corporate limit of Wapello (S35 T74N R3W Louisa Co.) to Long Cr (S1 T74N R4W Louisa Co.)

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.

Open Segment Map
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Cycle: 2020
Release Status: Final
Overall IR: 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend: Unknown
Created: 9/1/2020 2:50:51 PM
Updated: 10/9/2020 8:27:34 AM

Use Support

Class A1

Recreation - Primary contact

Partially Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Partially Supported

Impairment Code

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

Cause Magnitude

Slight

Status

Delisted

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2012

Impairment Rationale

Geometric mean criterion exceeded

Cycle Delisted

2020

Delisting Rationale

TMDL preparation and approval

Data Source

Ambient monitoring: USGS

Class BWW1

Aquatic Life - Warm Water Type 1

WINOFI

Biological: low aquatic macroinvertebrate IBI

Support Level

Further Investigation Needed

Impairment Code

3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2010

Impairment Rationale

Low Biotic Index

Data Source

Beach monitoring: Iowa DNR WQMA

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 primary contact recreation use was assessed as “partially supported” due to levels of indicator bacteria that exceeded state water quality criteria. The Class BWW1 aquatic life use was assessed as "partially supported" based on 2013 and 2017 biological sampling data. The Class HH (fish consumption) use was assessed as "fully supported" based on 2014 fish tissue sampling data and 2016-2018 water quality monitoring data. All other designated uses were "not assessed". Note: A TMDL covering the bacteria impairments for all segments, with the segment code prefix "IA 02-IOW" in the Iowa River Basin, was approved by EPA in 2018. Due to the completion of the TMDL, the IR category for the Class A1 use was changed from 5a (impaired; TMDL needed) to 4a (impaired; TMDL approved).

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	10580003	Iowa River near Wapello
USGS	11	WQ	CY 2016-2018	5465500	Iowa River at Wapello, IA
Iowa DNR	6	BIO	See Below	939	Iowa River	Wapello
Iowa DNR	6	FT	See Below	169	Iowa River	E of Wapello

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
10580003	6	24 / 3	202.28	56.43	49.07	Yes	6	25%	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
10580003	6	36 / 3	9.1	8.3	8.3	2	6%	No	Monitored	Full
5465500	11	42 / 3	8.8	8.2	8.2	0	0%	No	Monitored	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
10580003	6	Ammonia	36 / 3	0.65	0.09	0.02	0 / 0	0% / 0%	No	Monitored	Full
5465500	11	Ammonia	41 / 3	0.9	0.07	0.01	0 / 0	0% / 0%	No	Monitored	Full
10580003	6	Chloride	36 / 3	53	26	23	0 / 0	0% / 0%	No	Monitored	Full
5465500	11	Chloride	42 / 3	36.6	23.41	23.9	0 / 0	0% / 0%	No	Monitored	Full
10580003	6	Dissolved oxygen	36 / 3	14.9	10.5	10.5	NA / 0	NA / 0%	No	Monitored	Full
5465500	11	Dissolved oxygen	40 / 3	13.7	10.3	10.3	NA / 0	NA / 0%	No	Monitored	Full
10580003	6	pH	36 / 3	9.1	8.3	8.3	2 / NA	6% / NA	No	Monitored	Full
5465500	11	pH	42 / 3	8.8	8.2	8.2	0 / NA	0% / NA	No	Monitored	Full
10580003	6	Sulfate	36 / 3	59	27	24	0 / NA	0% / NA	No	Monitored	Full
5465500	11	Sulfate	42 / 3	42.7	25.41	25.55	0 / NA	0% / NA	No	Monitored	Full
10580003	6	Temperature	36 / 3	26.9	13.2	13.6	0 / 0	0% / 0%	No	Monitored	Full
5465500	11	Temperature	53 / 3	27.7	15.2	17.1	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
10580003	6	Aluminum	9 / 2	4.7	1.562	1.4	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Arsenic	9 / 2	3	2	1.8	0 / 0	0% / 0%	No	Evaluated	Full
5465500	11	Arsenic	42 / 3	2.4	1.5	1.4	0 / 0	0% / 0%	No	Monitored	Full
10580003	6	Cadmium	9 / 2	0.13	0.047	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Chromium	9 / 2	2	0.86	0.79	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Copper	9 / 2	4.8	1.79	1.1	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Lead	9 / 2	4.5	0.587	0.1	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Nickel	9 / 2	5.6	2.8	2.7	0 / 0	0% / 0%	No	Evaluated	Full
10580003	6	Selenium	9 / 2	3	1.67	1.7	0 / 0	0% / 0%	No	Evaluated	Full
5465500	11	Selenium	42 / 3	1.7	1.17	1.2	0 / 0	0% / 0%	No	Monitored	Full
10580003	6	Zinc	9 / 2	14	2.81	1.4	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	72d BMIBI BIT	BMIBI Pass/ Fail
939	10/10/17	12499	72d	MS/WW	Float ArtSub	37	Fair	51	Fail
939	10/8/13	12499	72d	MS/WW	ArtSub	20	Poor	51	Fail

Overall Assessment:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (0/2)	Partial	3bu	3bu	Assessment is evaluated because the drainage area of the site was larger than the calibrated range and the assessment used samples older than five years.

Class HH-F - 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
10580003	6	Cadmium	9 / 2	0.13	0.047	0.025	6	No	Evaluated	Full
10580003	6	Chromium	9 / 2	2	0.86	0.79	0	No	Evaluated	Full
10580003	6	Copper	9 / 2	4.8	1.79	1.1	0	No	Evaluated	Full
10580003	6	Nickel	9 / 2	5.6	2.8	2.7	0	No	Evaluated	Full
10580003	6	Selenium	9 / 2	3	1.67	1.7	0	No	Evaluated	Full
5465500	11	Selenium	42 / 3	1.7	1.17	1.2	0	No	Monitored	Full
10580003	6	Zinc	9 / 2	14	2.81	1.4	0	No	Evaluated	Full

Class HH – Fish Tissue Sampling:

Site ID

Date

Species Name

Biopart

# in sample

chlordane result

chlordane violation (>0.6)?

PCBs result

PCBs violation (>0.2)?

Hg result

Hg violation (>0.3)?

Assessment Type

Support Level

169

9/8/2014

common carp

whole

0.12

<0.24

0.11

Monitored

Full

Monitoring and Methods

Assessment Key Dates

9/8/2014

Fish Tissue Monitoring

1/4/2016

Fixed Monitoring Start Date

12/6/2018

Fixed Monitoring End Date

10/10/2017

Biological Monitoring

10/8/2013

Biological Monitoring

3/9/2018

TMDL Completed

Methods

150

Monitoring data more than 5 years old

220

Non-fixed station physical/chemical monitoring (conventional pollutant only)

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

380

Quantitative physical habitat assessment

420

Indicator bacteria monitoring