2022 Final assessment for Nodaway River (aka West Nodaway R.)

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

2022

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 2018 - 2020
Stream/River Water Quality Data	CY 2018 - 2020
Lake Water Quality Data	CY 2016 - 2020
Biological Sampling Data	CY 2016 - 2020*
Fish Kill Data	CY 2016 - 2020
Fish Tissue Sampling Data	CY 2016 - 2020
Continuous Dissolved Oxygen Sampling Data	CY 2016 - 2020
*Biological sites sampled in both 2015 and 2019 were also assessed.

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

Created: 12/27/2021 2:08:32 PM
Updated: 1/13/2022 2:34:37 PM

Assessment conducted in accordance with Iowa's 2022 IR methodology

Use Support

Class A1

Presumptive Use

Not Supported

Bacteria: Indicator Bacteria- E. coli

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

WINOFI

Biological: low aquatic macroinvertebrate IBI

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

Fully Supported

Class HH

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use was assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated water quality criteria. The Class BWW1 use was assessed as "WINOFI" based on biological sampling data. The Class C use as assessed as “fully supported” based on water quality monitoring data. All other designated uses were "not assessed."

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2014-2016, CY 2018-2020	10730001	West Nodaway River near Shambaugh
Iowa DNR	6	BIO	See Below	936	West Nodaway River	Shambaugh

Presumptive Class A1 - Indicator Bacteria: 2014-2016

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

Class A - pH

Site ID	Data Source ID	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	# Violations	Violations needed for impairment	Violates Significantly >10% Rule?	Assessment Type	Support Level
10730001	6	36 / 3	7.1	8.8	8	0	7	NO	Monitored	Full

Class BWW1 - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	# Violations	# Acute / Chronic Violations	Violations needed for impairment	Violates Significantly >10% Rule?	Assessment Type	Support Level
10730001	6	Ammonia	36 / 3	0.02	0.56	0.06	NA	0 / 0	7	NO	Monitored	Full
10730001	6	Chloride	36 / 3	5.8	15	9.9	NA	0 / 0	7	NO	Monitored	Full
10730001	6	Dissolved Oxygen	36 / 3	6.9	15.1	10.8	0	NA / NA	7	NO	Monitored	Full
10730001	6	pH	36 / 3	7.1	8.8	8	0	NA / NA	7	NO	Monitored	Full
10730001	6	Sulfate	36 / 3	4	34	17	0	NA / NA	7	NO	Monitored	Full
10730001	6	Temperature	36 / 3	0	30.4	13	0	NA / NA	7	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	>1 Acute / Chronic Violation	Assessment Type	Support Level
10730001	6	Aluminum	14 / 3	25	4.82	1.85	0 / 0	NO	Monitored	Full
10730001	6	Arsenic	13 / 3	3.9	1.8	1.5	0 / 0	NO	Monitored	Full
10730001	6	Cadmium	13 / 3	0.025	0.025	0.025	0 / 0	NO	Monitored	Full
10730001	6	Chromium	13 / 3	0.76	0.5	0.53	0 / 0	NO	Monitored	Full
10730001	6	Lead	13 / 3	0.36	0.11	0.08	0 / 0	NO	Monitored	Full
10730001	6	Nickel	13 / 3	4.5	3	3	0 / 0	NO	Monitored	Full
10730001	6	Silver	13 / 3	0.025	0.025	0.025	0 / 0	NO	Monitored	Full
10730001	6	Zinc	13 / 3	7	2.3	2.3	0 / 0	NO	Monitored	Full

Class C - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	Median Value	# Violations	Violates Significantly >10% Rule?	Assessment Type	Support Level
10730001	6	Chloride	36 / 3	5.8	15	9.9	9.8	0	NO	Monitored	Full
10730001	6	Inorganic nitrogen (nitrate and nitrite)	36 / 3	0.05	7	2.7	2.65	0	NO	Monitored	Full
10730001	6	pH	36 / 3	7.1	8.8	8	8	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	11 / 3	0.05	0.05	0.05	11	NO	Monitored	Full
10730001	6	Atrazine	11 / 3	0.4	0.1	0.05	7	NO	Monitored	Full
10730001	6	Simazine	11 / 3	0.05	0.05	0.05	11	NO	Monitored	Full

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47f BMIBI BIT	BMIBI Pass/Fail
936	8/12/20	777	47f	MO	Floating Art Sub	38	Fair	54	Fail
936	10/4/16	777	47f	MO	Floating Art Sub	34	Fair	54	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (0/2)	Not		Assessment was evaluated because the drainage area of the sample site
Overall	Evaluated	Fail	WINOFI	3bu	was larger than the calibrated range.

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

1/7/2014	Fixed Monitoring Start Date
12/6/2016	Fixed Monitoring End Date
10/4/2016	Biological Monitoring
1/8/2018	Fixed Monitoring Start Date
12/1/2020	Fixed Monitoring End Date
8/12/2020	Biological Monitoring

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

Water Quality Assessments

Impaired Waters List

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

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods