2024 Pending assessment for Wapsipinicon River

Wapsipinicon River IA 01-WPS-343

from Harter Cr. at Independence (NW 1/4 S34 T89N R9W Buchanan Co.) to confluence with Little Wapsipinicon R. near Littleton in S9 T89N R10W Buchanan Co.

Assessment Cycle

2024

Release Status

Pending

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 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

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

Created: 11/1/2023 8:12:25 AM
Updated: 1/22/2024 1:45:41 PM

Assessment conducted in accordance with Iowa's 2024 IR methodology.

Use Support

Class A1

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not 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

Single-sample maximum criterion exceeded in significantly > 10% of samples

Data Source

Ambient monitoring: Iowa DNR-rivers

TMDL Priority

Tier III

Class BWW1

WINOFI

Fish Kill: Cause Unknown

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

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2024

Impairment Rationale

Potential Impairment

Data Source

Fish kill investigation: Iowa DNR

Class HH

Not Supported

Fish Consumption Advisory: Mercury

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2022

Impairment Rationale

Fish consumption advisory in effect: no more than 1 meal/week

Data Source

Fish contaminant monitoring: Iowa DNR

TMDL Priority

Tier IV

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use was assessed as “not supported” based on levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "WINOFI" based on the occurrence of a single fish kill in this segment. The Class HH (fish consumption) use was assessed as “not supported” based on fish tissue monitoring data and on the historical existence of a one meal/week mercury consumption advisory for walleye on this segment.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2020-2022	10100001	Wapsipinicon River near Independence (US1)
Iowa DNR	6	BIO	See Below	949	Wapsipinicon River	Independence
Iowa DNR	6	FT	See Below	1366	Wapsipinicon River	Otterville Bridge
Iowa DNR	6	FT	See Below	1379	Wapsipinicon River	Otterville WMA Boat Ramp

Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2020/ 2021/2022)

2020 Geometric Mean

2021 Geometric Mean

2022 Geometric Mean

Violates Annual Geometric Mean?

# 2020 SSM violations / SSM Violations needed for impairment

# 2021 SSM violations / SSM Violations needed for impairment

# 2022 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

10100001

7/7/8

103

243

YES

1 / 3

0 / 3

3 / 3

YES

Mon

Not

Class A1 – 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
10100001	6	36 / 3	7.4	8.6	8	0	7	NO	Mon	Full

Class BWW1 - Binomial 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
10100001	6	Chloride	36 / 3	7.1	27	19.9	NA	0 / 0	7	NO	Mon	Full
10100001	6	Dissolved Oxygen	36 / 3	6	14.3	10.5	0	NA / NA	7	NO	Mon	Full
10100001	6	pH	36 / 3	7.4	8.6	8	0	NA / NA	7	NO	Mon	Full
10100001	6	Sulfate	36 / 3	6.3	31	20.2	0	NA / NA	7	NO	Mon	Full
10100001	6	Temperature	36 / 3	0.1	28.1	11.9	0	NA / NA	7	NO	Mon	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
10100001	6	Aluminum	21 / 3	2200	358	100	0 / 1	NO	Mon	Full
10100001	6	Ammonia	36 / 3	0.68	0.06	0.02	0 / 0	NO	Mon	Full
10100001	6	Cadmium	20 / 3	0.5	0.5	0.5	0 / 0	NO	Mon	Full
10100001	6	Chromium	20 / 3	1	0.47	0.38	0 / 0	NO	Mon	Full
10100001	6	Lead	20 / 3	1	0.91	1	0 / 0	NO	Mon	Full
10100001	6	Nickel	20 / 3	2.3	1.1	0.9	0 / 0	NO	Mon	Full
10100001	6	Selenium	18 / 2	1	0.6	0.5	0 / 0	NO	Mon	Full
10100001	6	Silver	20 / 3	1	0.902	1	0 / 0	NO	Mon	Full
10100001	6	Zinc	20 / 3	2.5	0.8	0.5	0 / 0	NO	Mon	Full

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47c BMIBI BIT	BMIBI Pass/Fail
949	8/26/21	909	47c	MS	Art Sub	65	Good	52	Pass
949	10/3/17	909	47c	MS	Art Sub	63	Good	52	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrate	Evaluated	Pass (2/2)	Full		Assessment was evaluated because the drainage area of the sample site was
Overall	Evaluated	Pass	Full	1	greater than the calibrated range.

Class BWW1 – Fish kill Assessment:

The Class BWW1 aquatic life use assessment based on the 2021 fish kill placed this segment in Category 3b. This assessment was “evaluated” because there was a single fish kill on this segment in the last five years. Segments assessed using “evaluated” assessments are placed in Category 3b and are added to the state list of Waters In Need Of Further Investigation (WINOFI). If no additional fish kills are reported in this segment for a 5-year period (2026), the Category will be changed from 3b to 3a (not assessed).

Details about the 2021 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/1015

Class HH - Fish Tissue Sampling:

Site ID	Biopart	Year	Species	# in sample / # of samples	Avg Length (cm)	(Avg) Hg (ppm)	Chlordane (ppm)	Sum PCBs (ppm)
1379	tissue plug	2021	smallmouth bass	20	26.6	0.113
1366	tissue plug	2020	northern pike	10	69	0.294
1366	tissue plug	2020	walleye	1	49.8	0.4
1366	tissue plug	2019	walleye	9	48.5	0.384
Support Level	Not	A historic one meal/week mercury consumption advisory for walleye exists on this segment. Based on IR Methodology, the Class HH (fish consumption) use was assessed as “not supported.”

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
10100001	6	Selenium	18 / 2	1	0.6	0.5	16	NO	Mon	Full

Monitoring and Methods

Assessment Key Dates

1/9/2020	Monitoring Start
12/8/2022	Monitoring End
10/3/2017	Biological Monitoring
9/3/2019	Fish Tissue Monitoring
4/7/2020	Fish Tissue Monitoring
8/26/2021	Biological Monitoring
6/17/2021	Fish Tissue Monitoring
7/26/2021	Fish Kill

Methods

120	Surveys of fish and game biologists/other professionals
140	Incidence of spills and/or fish kills
200	Physical/Chemical Monitoring
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

Wapsipinicon River IA 01-WPS-343

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods