2020 Final assessment for Upper Iowa River

Upper Iowa River IA 01-UIA-237

from Lane's Bridge (NW 1/4 S31 T100N R4W Allamakee Co.) to confluence with Canoe Cr. in S25 T99N R7W Winneshiek 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: Unknown

Created: 8/21/2020 2:43:04 PM
Updated: 12/6/2021 8:15:27 AM

Assessment conducted in accordance with Iowa's 2020 IR methodology

Use Support

Class A1

Partially Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Partially Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2004

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: Iowa DNR-rivers

TMDL Priority

Tier III

Class BWW1

Fully Supported

Class HH

Partially Supported

Fish Consumption Advisory: Mercury

Support Level

Partially Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2006

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

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use was assessed as “partially supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data. The Class HH use remains assessed as “partially supported” based on 2010 fish tissue sampling data and on the continuance of a fish consumption advisory for this segment of the Upper Iowa River.

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	10030001	Upper Iowa River near Dorchester
Iowa DNR	6	BIO	See Below	288	Upper Iowa River	Dorchester
Iowa DNR	6	FT	See Below	113	Upper Iowa River	SE of Dorchester

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
10030001	6	20 / 3	125.38	132.36	322.01	Yes	9	45%	Yes	Monitored	Partial

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
10030001	6	36 / 3	8.5	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
10030001	6	Ammonia	36 / 3	0.43	0.04	0.02	0 / 0	0% / 0%	No	Monitored	Full
10030001	6	Chloride	36 / 3	20	15.8	16	0 / 0	0% / 0%	No	Monitored	Full
10030001	6	Dissolved oxygen	36 / 3	14.3	11	11	NA / 0	NA / 0%	No	Monitored	Full
10030001	6	pH	36 / 3	8.5	8.2	8.2	0 / NA	0% / NA	No	Monitored	Full
10030001	6	Sulfate	36 / 3	22	16	16	0 / NA	0% / NA	No	Monitored	Full
10030001	6	Temperature	36 / 3	24.3	11.2	11.5	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
10030001	6	Aluminum	9 / 2	8.3	1.483	0.26	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Arsenic	9 / 2	0.97	0.62	0.68	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Cadmium	9 / 2	0.025	0.025	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Chromium	9 / 2	1.3	1.04	1	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Copper	9 / 2	1.4	0.72	0.54	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Lead	9 / 2	0.33	0.091	0.07	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Nickel	9 / 2	2.6	2	1.9	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Selenium	9 / 2	1.5	0.9	0.84	0 / 0	0% / 0%	No	Evaluated	Full
10030001	6	Zinc	9 / 2	4.2	1.71	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	52b BMIBI BIT	BMIBI Pass/ Fail
288	8/16/16	768	52b	MS/WW	Hess	84	Excellent	61	Pass
288	8/16/16	768	52b	MS/WW	Float ArtSub	78	Excellent	61	Pass
288	10/8/14	768	52b	MS/WW	Hess	70	Good	61	Pass
288	10/8/14	768	52b	MS/WW	Float ArtSub	81	Excellent	61	Pass

Overall Assessment:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Monitored	Pass (4/4)	Full	1	Assessment is monitored because two or more samples collected in last five years were used to complete the assessment.

Class HH – Fish Tissue Sampling:

Site ID	Date	Species Name	Biopart	# in sample	Hg result	Hg violation (>0.3)?	Assessment Type	Support Level
113	8/26/2010	golden redhorse	fillet	5	0.318	Yes	Evaluated	Partial
113	8/26/2010	smallmouth bass	fillet	5	0.392	Yes	Evaluated	Partial
A one meal/week consumption advisory for mercury exists on this Segment of the Upper Iowa River – seeIowa Consumption Advisories

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
10030001	6	Cadmium	9 / 2	0.025	0.025	0.025	9	No	All Non-Detect	Full
10030001	6	Chromium	9 / 2	1.3	1.04	1	0	No	Evaluated	Full
10030001	6	Copper	9 / 2	1.4	0.72	0.54	0	No	Evaluated	Full
10030001	6	Nickel	9 / 2	2.6	2	1.9	0	No	Evaluated	Full
10030001	6	Selenium	9 / 2	1.5	0.9	0.84	1	No	Evaluated	Full
10030001	6	Zinc	9 / 2	4.2	1.71	1.4	0	No	Evaluated	Full

Monitoring and Methods

Assessment Key Dates

8/26/2010	Fish Tissue Monitoring
1/11/2016	Fixed Monitoring Start Date
12/5/2018	Fixed Monitoring End Date
10/8/2014	Biological Monitoring
8/16/2016	Biological Monitoring

Methods

150	Monitoring data more than 5 years old
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

Water Quality Assessments

Impaired Waters List

Upper Iowa River IA 01-UIA-237

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods