Nodaway River (aka West Nodaway R.) IA 05-NOD-1389

from confluence with East Nodaway R. (S6 T67N R36W Page Co.) to confluence with Middle Nodaway R. in S33 T71N R36W Montgomery 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: 9/17/2020 10:56:07 AM
Updated: 10/19/2020 7:03:19 AM

Assessment conducted in accordance with Iowa's 2020 IR methodology

Use Support

Class A1

Recreation

Primary contact

Presumptive Use

Not Supported

Impairments

Support Level

Not Supported

Impairment Code

5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.

Cause Magnitude

Moderate

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

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2008

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

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 presumptive Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated water quality criteria. The Class BWW1 use remains assessed as "partially supported" based on biological sampling data. The Class C and Class HH uses were assessed as “fully supported” based on 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 2014-2016, CY 2016-2018	10730001	West Nodaway River near Shambaugh
Iowa DNR	6	BIO	See Below	936	West Nodaway River	Shambaugh

Presumptive Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2014 Geo. Mean	2015 Geo. Mean	2016 Geo. Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
10730001	6	24 / 3	1505	911	1133	Yes	21	88%	Yes	Evaluated	Not

Presumptive 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
10730001	6	36 / 3	9	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
10730001	6	Ammonia	36 / 3	0.51	0.05	0.02	0 / 0	0% / 0%	No	Monitored	Full
10730001	6	Chloride	36 / 3	15	9.4	9.3	0 / 0	0% / 0%	No	Monitored	Full
10730001	6	Dissolved oxygen	36 / 3	15.1	10.7	10.8	NA / 0	NA / 0%	No	Monitored	Full
10730001	6	pH	36 / 3	9	8.2	8.2	0 / NA	0% / NA	No	Monitored	Full
10730001	6	Sulfate	36 / 3	34	18	18	0 / NA	0% / NA	No	Monitored	Full
10730001	6	Temperature	36 / 3	30.4	14.5	14.9	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
10730001	6	Aluminum	9 / 2	25	4.39	2	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Arsenic	9 / 2	3.9	2	1.7	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Cadmium	9 / 2	0.025	0.025	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Chromium	9 / 2	0.92	0.46	0.43	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Copper	9 / 2	2.5	1.1	1	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Lead	9 / 2	0.27	0.073	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Nickel	9 / 2	4.5	2.6	2.2	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Selenium	9 / 2	2	1.42	1.3	0 / 0	0% / 0%	No	Evaluated	Full
10730001	6	Zinc	9 / 2	3	1.35	1.2	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	47f BMIBI BIT	BMIBI Pass/ Fail
936	10/4/16	777	47f	MO/WW	Float ArtSub	34	Fair	54	Fail
936	10/1/13	777	47f	MO/WW	ArtSub	31	Fair	54	Fail

Overall:

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.

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
10730001	6	Chloride	36 / 3	15	9.4	9.3	0	0%	No	Monitored	Full
10730001	6	Inorganic nitrogen (nitrate and nitrite)	36 / 3	7	3.48	3.45	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
10730001	6	Alachlor	3 / 1	0.05	0.05	0.05	3	No	Evaluated	Full
10730001	6	Atrazine	3 / 1	0.05	0.05	0.05	3	No	Evaluated	Full
10730001	6	Cadmium	9 / 2	0.025	0.025	0.025	9	No	Evaluated	Full
10730001	6	Chromium	9 / 2	0.92	0.46	0.43	0	No	Evaluated	Full
10730001	6	Lead	9 / 2	0.27	0.073	0.025	5	No	Evaluated	Full
10730001	6	Silver	9 / 2	0.025	0.025	0.025	9	No	Evaluated	Full
10730001	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
10730001	6	Copper	9 / 2	2.5	1.1	1	0	No	Evaluated	Full
10730001	6	Nickel	9 / 2	4.5	2.6	2.2	0	No	Evaluated	Full
10730001	6	Selenium	9 / 2	2	1.42	1.3	0	No	Evaluated	Full
10730001	6	Zinc	9 / 2	3	1.35	1.2	0	No	Evaluated	Full

Monitoring and Methods

Assessment Key Dates

1/7/2014

Fixed Monitoring Start Date

12/6/2016

Fixed Monitoring End Date

10/1/2013

Biological Monitoring

10/4/2016

Biological Monitoring

1/4/2016

Fixed Monitoring Start Date

12/4/2018

Fixed Monitoring End Date

Methods

150

Monitoring data more than 5 years old

230

Fixed station physical/chemical (conventional plus toxic pollutants)

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

420

Indicator bacteria monitoring