Wolf Creek IA 05-CHA-1339

mouth (S15 T71N R21W Lucas Co.) to confluence with unnamed tributary in E 1/2 NW 1/4 S8 T70N R22W Wayne 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 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.

Open Segment Map
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Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Stable
Created: 11/1/2023 8:12:27 AM
Updated: 2/2/2024 1:55:18 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

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: Corps of Engineers/Iowa DNR/ISU

TMDL Priority

Tier III

Class BWW2

Aquatic Life - Warm Water Type 2

Not Supported

Biological: low fish & invert IBIs- cause unknown

Support Level

Not Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2008

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

TMDL Priority

Tier IV

Organic Enrichment: Low Dissolved Oxygen

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2016

Impairment Rationale

Potential Impairment

Data Source

Special project/study: Iowa DNR

Temperature: Thermal Modifications

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2016

Impairment Rationale

Potential Impairment

Data Source

Special project/study: Iowa DNR

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 was assessed as “not supported” based on biological sampling data and on continuous dissolved oxygen and temperature monitoring data.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
USACE	12	WQ	CY 2010-2014	15590003	Wolf Creek at CR H50/430th (Site RA-41)
USACE	12	WQ	CY 2010-2014	15930007	Wolf Creek at CR S23/100th (Site RA-44)
Iowa DNR	6	BIO	See Below	207	Wolf Creek	Chariton

Presumptive Class A1 - Indicator Bacteria: 2010-2012

Site ID	Data Source ID	# Samples / # Years	2010 Geometric Mean	2011 Geometric Mean	2012 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15590003	12	19 / 3	959	185	2469	Yes	15	79%	Yes	Evaluated	Not
15930007	12	15 / 3	470	138	632	Yes	8	53%	Yes	Evaluated	Not

Presumptive Class A1 - pH: 2012-2014

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15590003	12	53 / 3	8	7.5	7.6	0	0%	No	Evaluated	Full
15930007	12	35 / 3	8	7.9	7.5	0	0%	No	Evaluated	Full

Class BWW2 - Binomial Parameters: 2012-2014

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
15590003	12	Ammonia	28 / 3	0.66	0.11	0.05	0 / 0	0% / 0%	No	Evaluated	Full
15930007	12	Ammonia	21 / 3	0.7	0.12	0.05	0 / 0	0% / 0%	No	Evaluated	Full
15590003	12	Chloride	34 / 3	14	6.8	6.4	0 / 0	0% / 0%	No	Evaluated	Full
15930007	12	Chloride	14 / 3	13	7.2	6.7	0 / 0	0% / 0%	No	Evaluated	Full
15590003	12	Dissolved oxygen	53 / 3	11.7	8.3	7.9	NA / 1	NA / 2%	No	Evaluated	Full
15930007	12	Dissolved oxygen	35 / 3	12.3	8.4	8.2	NA / 1	NA / 3%	No	Evaluated	Full
15590003	12	pH	53 / 3	8	7.5	7.6	0 / NA	0% / NA	No	Evaluated	Full
15930007	12	pH	35 / 3	8	7.9	7.5	0 / NA	0% / NA	No	Evaluated	Full
15590003	12	Temperature	53 / 3	27.5	17.1	17.8	0 / 0	0% / 0%	No	Evaluated	Full
15930007	12	Temperature	35 / 3	25.1	16.3	18.1	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW2 - Biological Sampling:

Benthic Macroinvertebrates:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	40a BMIBI BIT	BMIBI Pass/Fail
207	9/11/19	65.7	40a	MO	Surber	37	Fair	41	Fail
207	9/14/15	65.7	40a	MO	Hess	37	Fair	41	Fail
207	8/3/15	65.7	40a	MO	Hess	43	Fair	41	Pass

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	40a FIBI BIT	FIBI Pass/Fail
207	9/11/19	65.7	40a	MO	NA	45	Fair	33	Pass
207	9/14/15	65.7	40a	MO	NA	17	Poor	33	Fail

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (1/3)	Not
Fish	Evaluated	Fail (1/2)	Not	5bv	Assessment was evaluated because some of the samples used to complete
Overall	Evaluated	Fail	Not		the assessment were not collected in the last five years.

Class BWW2 – Continuous Monitoring Data:

The results of continuous dissolved oxygen (DO) and temperature monitoring in 2012 for the DNR/SHL sampling project do suggest impairment of Class BWW2 aquatic life uses. The lowest DO concentration recorded in 69 days of continuous monitoring was 2.1 mg/L. The daily DO minimum concentration failed to meet the 24-hour DO criterion (4 mg/L) in 29 of 69 days and the 16-hour DO criterion (5 mg/L) in 9 of 69 days. The percentages exceeding the 24-hour and 16-hour DO criteria (42.0% and 13.0%, respectively) were greater than (failing) the 10% impairment threshold used to assess Binomial water quality parameters. The associated statistical analysis confidence level for the 24-hour analysis result was high (>90%), while the confidence level for the 16-hour analysis result was not high (<90%). The maximum stream temperature recorded during the sensor deployment period was 34.2 degrees (C). The temperature criterion for warm water interior streams (32 C) was exceeded in 15 of 69 days. The percentage exceeding (21.7%) was greater than (failing) the 10% impairment threshold with high statistical confidence (>90%). Based on these data, the BWW2 aquatic life use was assessed as impaired for DO and temperature. The assessment type is “evaluated” because it is based on data collected from a single year within the current data assessment period. In order to meet the requirements for a “monitored” assessment, the DNR’s continuous monitoring assessment methodology requires monitoring data from two or more years within the assessment period.

Monitoring and Methods

Assessment Key Dates

3/15/2012

Monitoring Start

10/21/2014

Monitoring End

9/11/2019

Biological Monitoring

8/3/2015

Biological Monitoring

9/14/2015

Biological Monitoring

3/22/2010

Monitoring Start

10/22/2012

Monitoring End

Methods

150

Monitoring data more than 5 years old

200

Physical/Chemical Monitoring

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring