Muddy Creek IA 02-IOW-2043

from mouth (S33 T80N R6W Johnson Co.) to headwaters in SW 1/4 S12 T80N R7W Johnson Co.

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 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.

Open Segment Map
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Cycle: 2020
Release Status: Final
Overall IR: 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend: Unknown
Created: 9/21/2020 1:47:20 PM
Updated: 10/12/2020 8:46:42 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

4a - Pollutant-caused impairment. TMDL has been completed.

Cause Magnitude

High

Status

Delisted

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Cycle Delisted

2020

Delisting Rationale

TMDL preparation and approval

Data Source

Special project/study

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

WINOFI

Biological: low fish IBI

Support Level

Further Investigation Needed

Impairment Code

3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2008

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use remains assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded Iowa’s water quality criteria. The presumptive Class BWW1 use remains assessed as “partially supported” based on biological sampling data. Note: A TMDL covering the bacteria impairments for all segments, with the segment code prefix "IA 02-IOW" in the Iowa River Basin, was approved by EPA in 2018. Due to the completion of the TMDL, the IR category for the Class A1 use was changed from 5p (impaired; TMDL needed) to 4a (impaired; TMDL approved).

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
USGS	11	WQ	CY 2016-2018	5454050	Muddy Cr abv Trtmnt Outfall at North Liberty, IA
USGS	11	WQ	CY 2016-2018	5454052	Muddy Cr blw Trtmnt Outfall at North Liberty, IA
USGS	11	WQ	CY 2016-2018	5454090	Muddy Creek at Coralville, IA
Iowa DNR	6	WQ	CY 2012-2013	15520002	Muddy Creek at Golf View Dr (MCB)
Iowa DNR	6	WQ	CY 2012-2013	15520003	Muddy Creek at 1st Ave (MC3)
Iowa DNR	6	WQ	CY 2012-2013	16520003	Muddy Creek (MCR1)
Iowa DNR	6	WQ	CY 2012-2013	16520004	Muddy Creek (MCR2)
Iowa DNR	6	BIO	See Below	630	Muddy Creek	North Liberty – DS WWTP

Presumptive Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2012 Geometric Mean	2013 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15520002	6	21 / 2	1126	1520	Yes	19	90%	Yes	Evaluated	Not
15520003	6	21 / 2	897	848	Yes	21	100%	Yes	Evaluated	Partial
16520003	6	21 / 2	724	1205	Yes	19	90%	Yes	Evaluated	Not
16520004	6	21 / 2	949	707	Yes	19	90%	Yes	Evaluated	Partial

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
5454050	11	14 / 3	7.7	7.5	7.5	0	0%	No	Monitored	Full
5454052	11	14 / 3	8	7.6	7.6	0	0%	No	Monitored	Full
5454090	11	14 / 3	8.2	7.9	7.9	0	0%	No	Monitored	Full

Presumptive 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
5454050	11	Dissolved oxygen	14 / 3	13.5	8.8	8	NA / 0	NA / 0%	No	Monitored	Full
5454052	11	Dissolved oxygen	14 / 3	11.7	9	8.4	NA / 0	NA / 0%	No	Monitored	Full
5454090	11	Dissolved oxygen	14 / 3	14.4	10.3	9.4	NA / 0	NA / 0%	No	Monitored	Full
5454050	11	pH	14 / 3	7.7	7.5	7.5	0 / NA	0% / NA	No	Monitored	Full
5454052	11	pH	14 / 3	8	7.6	7.6	0 / NA	0% / NA	No	Monitored	Full
5454090	11	pH	14 / 3	8.2	7.9	7.9	0 / NA	0% / NA	No	Monitored	Full
5454050	11	Temperature	14 / 3	21.4	11.4	14.3	0 / 0	0% / 0%	No	Monitored	Full
5454052	11	Temperature	14 / 3	21.5	16.6	18	0 / 0	0% / 0%	No	Monitored	Full
5454090	11	Temperature	14 / 3	22	12	14	0 / 0	0% / 0%	No	Monitored	Full

Presumptive 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
630	10/12/09	4	47f	MS/WW	ArtSub	54	Fair	51	Pass

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/ Thermal	Riffle Stream?	FIBI score	FIBI Class	47f FIBI BIT	FIBI Pass/ Fail
630	9/29/10	4	47f	MS/WW	NA	30	Fair	36	Fail
630	10/12/09	4	47f	MS/WW	NA	13	Poor	36	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (1/1)	Full
Fish	Evaluated	Fail (0/2)	Partial
Overall	Evaluated	Fail	Partial	3bu	3bu	Assessment is evaluated because the drainage area of the sampling site was smaller than the calibrated range.

Monitoring and Methods

Assessment Key Dates

10/12/2009

Biological Monitoring

9/29/2010

Biological Monitoring

5/1/2012

Non-fixed Monitoring Start Date

8/30/2013

Non-fixed Monitoring End Date

8/1/2016

Non-fixed Monitoring Start Date

8/1/2018

Non-fixed Monitoring End Date

3/9/2018

TMDL Completed

Methods

150

Monitoring data more than 5 years old

220

Non-fixed station physical/chemical monitoring (conventional pollutant only)

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring