2020 Final assessment for Nutting Creek

Nutting Creek IA 01-TRK-205

mouth (S19 T95N R7W Fayette Co.) to confluence with unnamed tributary in S2 T95N R8W Fayette 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: 8/21/2020 10:00:21 AM
Updated: 10/15/2020 12:56:42 PM

Assessment conducted in accordance with Iowa's 2020 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

High

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

TMDL monitoring: Iowa DNR

TMDL Priority

Tier III

Class BWW2

Fully Supported

General Use

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use remains assessed as "fully supported" based on biological sampling data.

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2006-2007	11330001	Nutting Creek	Site NuCr1
Iowa DNR	6	BIO	See Below	554	Nutting Creek	Clermont – NuCr1

Presumptive Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2006/07 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11220014	6	14 / 2	4087	Yes	10	71%	Yes	Evaluated	Not

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/ Thermal	BM Sample Gear	BMIBI score	BMIBI Class	52b BMIBI BIT	BMIBI Pass/ Fail
554	9/13/10	27	52b	MS/WW	Hess	77	Excellent	61	Pass
554	9/21/09	27	52b	MS/WW	Hess	74	Good	61	Pass

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/ Thermal	Riffle Stream?	FIBI score	FIBI Class	52b FIBI BIT	FIBI Pass/ Fail
554	9/13/10	27	52b	MS/WW	NA	65	Good	52	Pass
554	9/21/09	27	52b	MS/WW	NA	66	Good	52	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (2/2)	Full
Fish	Evaluated	Pass (2/2)	Full
Overall	Evaluated	Pass	Full	1	1	Assessment is evaluated because the samples used to complete the assessment were not collected in the last five years.

Monitoring and Methods

Assessment Key Dates

6/29/2006	Fixed Monitoring Start Date
6/20/2007	Fixed Monitoring End Date
9/21/2009	Biological Monitoring
9/13/2010	Biological Monitoring

Methods

150	Monitoring data more than 5 years old
315	Regional reference site approach
320	Benthic macroinvertebrate surveys
330	Fish surveys
420	Indicator bacteria monitoring

Water Quality Assessments

Impaired Waters List

Nutting Creek IA 01-TRK-205

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods