2020 Final assessment for Wapsipinicon River

Wapsipinicon River IA 01-WPS-332

mouth (Scott-Clinton county line) to confluence with Silver Cr. in NW 14 S6 T80N R4E Clinton 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: 8/12/2020 2:17:36 PM
Updated: 10/15/2020 1:29:50 PM

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

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

Data Source

Ambient monitoring: Iowa DNR-rivers

TMDL Priority

Tier III

Class BWW1

Fully Supported

Class HH

Fully Supported

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 Class A1 criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data. The Class HH use was 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	BioNet Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2016-2018	10820001		Wapsipinicon River at De Witt
LTRMP	17	WQ	CY 2016-2018	99990006		Wapsipinicon River
Iowa DNR	6	BIO	See Below		844	Wapsipinicon River at De Witt	Ambient Monthly WQ

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
10820001	6	22 / 3	268.25	185.59	241.04	Yes	11	50%	Yes	Monitored	Partial

Class A - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
10820001	6	36 / 3	8.6	8	8.1	0	0%	No	Monitored	Full
99990006	17	41 / 3	8.8	7.9	7.9	1	2%	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
10820001	6	Ammonia	36 / 3	0.65	0.06	0.02	0 / 0	0% / 0%	No	Monitored	Full
99990006	17	Ammonia	41 / 3	0.331	0.03	0.02	0 / 0	0% / 0%	No	Monitored	Full
10820001	6	Chloride	36 / 3	25	18.6	19	0 / 0	0% / 0%	No	Monitored	Full
10820001	6	Dissolved oxygen	36 / 3	14.1	10	10	NA / 0	NA / 0%	No	Monitored	Full
99990006	17	Dissolved oxygen	42 / 3	15.2	9.9	9.9	NA / 0	NA / 0%	No	Monitored	Full
10820001	6	pH	36 / 3	8.6	8	8.1	0 / NA	0% / NA	No	Monitored	Full
99990006	17	pH	41 / 3	8.8	7.9	7.9	1 / NA	2% / NA	No	Monitored	Full
10820001	6	Sulfate	36 / 3	28	17.8	18	0 / NA	0% / NA	No	Monitored	Full
10820001	6	Temperature	36 / 3	27.3	12.2	12	0 / 0	0% / 0%	No	Monitored	Full
99990006	17	Temperature	42 / 3	28.1	16.2	17.4	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
10820001	6	Aluminum	9 / 2	6.5	1.852	1.6	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Arsenic	9 / 2	1.2	0.82	0.93	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Cadmium	9 / 2	0.1	0.033	0.025	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Chromium	9 / 2	1.1	0.64	0.67	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Copper	9 / 2	4	1.37	0.81	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Lead	9 / 2	1.1	0.19	0.07	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Nickel	9 / 2	2.4	1.9	2.1	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Selenium	9 / 2	1.2	0.63	0.63	0 / 0	0% / 0%	No	Evaluated	Full
10820001	6	Zinc	9 / 2	3.9	1.28	0.8	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47f BMIBI BIT	BMIBI Pass/ Fail
844	8/6/18	2334	47f	MS	Floating Art Sub	71	Good	51	Pass
844	10/2/14	2334	47f	MS	Floating Art Sub	56	Good	51	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrate	Evaluated	Pass (2/2)	Full
Overall	Evaluated	Pass	Full	1	1	Assessment is evaluated because segment did not have two BM and/or fish samples collected in last five years and watershed size was larger than calibrated range.

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
10820001	6	Cadmium	9 / 2	0.1	0.033	0.025	8	No	Evaluated	Full
10820001	6	Chromium	9 / 2	1.1	0.64	0.67	0	No	Evaluated	Full
10820001	6	Copper	9 / 2	4	1.37	0.81	0	No	Evaluated	Full
10820001	6	Nickel	9 / 2	2.4	1.9	2.1	0	No	Evaluated	Full
10820001	6	Selenium	9 / 2	1.2	0.63	0.63	2	No	Evaluated	Full
10820001	6	Zinc	9 / 2	3.9	1.28	0.8	0	No	Evaluated	Full

Monitoring and Methods

Assessment Key Dates

1/5/2016	Fixed Monitoring Start Date
12/6/2018	Fixed Monitoring End Date
8/6/2018	Biological Monitoring
10/2/2014	Biological Monitoring

Methods

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

Wapsipinicon River IA 01-WPS-332

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods