Wapsipinicon River IA 01-WPS-6416

from north line of S20 T100N R15W Mitchell Co to Minnesota border(T100N R15W Sec7 NW)

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 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.

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Cycle: 2022
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 12/28/2021 8:46:54 AM
Updated: 1/18/2022 3:14:34 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

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

New

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2022

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: adjacent state

TMDL Priority

Tier IV

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

WINOFI

Fish Kill: Cause Unknown

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2018

Impairment Rationale

Potential Impairment

Data Source

Fish kill investigation: Iowa DNR

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 exceeded state water quality criteria. The presumptive Class BWW1 use was assessed as “WINOFI” due to a fish kill investigation.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
MNPCA	15	WQ	CY 2019-2020	99990107	Wapsipinicon River

Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2018/ 2019/2020)

2018 Geometric Mean

2019 Geometric Mean

2020 Geometric Mean

Violates Annual Geometric Mean?

# 2018 SSM violations / SSM Violations needed for impairment

# 2019 SSM violations / SSM Violations needed for impairment

# 2020 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

99990107

0/9/6

1288

947

YES

7 / 3

6 / NA

YES

Monitored

Not

Presumptive 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
99990107	15	25 / 2	6.7	8.6	7.8	0	5	NO	Monitored	Full

Presumptive 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
99990107	15	Dissolved Oxygen	25 / 2	7.93	17.67	11.75	0	NA / NA	5	NO	Monitored	Full
99990107	15	pH	25 / 2	6.7	8.6	7.8	0	NA / NA	5	NO	Monitored	Full
99990107	15	Temperature	25 / 2	10.4	25.8	18.4	0	NA / NA	5	NO	Monitored	Full

Presumptive Class BWW1 – Fish kill Assessment:

The presumptive Class BWW1 aquatic life use assessment based on the 2016 fish kill placed this segment in Category 3b. Because the cause of the fish kill was not identified, or the fish kill was attributed to a non-pollutant cause (e.g., winterkill), the assessment type is “evaluated.” Segments assessed using “evaluated” assessments are placed in Category 3b Waters In Need Of Further Investigation (WINOFI) and are added to the state list of waters in need of further investigation. If no additional fish kills are reported in the segment for a 10 year period (2026), the Category will be changed from 3b to 3a (water not assessed).

Details about the 2016 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/917

Monitoring and Methods

Assessment Key Dates

4/28/2016

Fish Kill

5/13/2019

Fixed Monitoring Start Date

9/29/2020

Fixed Monitoring End Date

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

210

Fixed station physical/chemical monitoring (conventional pollutants only)

420

Indicator bacteria monitoring