2022 Final assessment for White Breast Creek

White Breast Creek IA 04-LDM-1059

from mouth (S10 T76N R19W Marion Co.) to confluence with Little White Breast Cr. in S11 T73 R22 Lucas Co.

Assessment Cycle

2022

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 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.

Overall IR Category: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown

Created: 12/27/2021 9:59:02 AM
Updated: 1/7/2022 11:18:05 AM

Assessment conducted in accordance with Iowa's 2022 IR methodology

Use Support

Class A1

Not Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: Iowa DNR-rivers

TMDL Priority

Tier III

Class BWW1

Fully Supported

Class HH

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use was assessed as "not supported" due to levels of indicator bacteria that violated state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and on water quality monitoring data. All other designated uses were "not assessed."

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2018-2020	10630003	Whitebreast Creek near Dallas
Iowa DNR	6	BIO	See Below	1150	Whitebreast Creek	10 miles SW of Knoxville

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

10630003

7/7/8

367

1033

241

YES

4 / 3

7 / 3

4 / 3

YES

Monitored

Not

Class A - 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
10630003	6	35 / 3	6.8	8.5	7.8	0	7	NO	Monitored	Full

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
10630003	6	Ammonia	35 / 3	0.02	0.46	0.06	NA	0 / 0	7	NO	Monitored	Full
10630003	6	Chloride	36 / 3	10	140	34	NA	0 / 0	7	NO	Monitored	Full
10630003	6	Dissolved Oxygen	36 / 3	5.8	13.3	10.3	0	NA / NA	7	NO	Monitored	Full
10630003	6	pH	35 / 3	6.8	8.5	7.8	0	NA / NA	7	NO	Monitored	Full
10630003	6	Sulfate	36 / 3	17	76	41	0	NA / NA	7	NO	Monitored	Full
10630003	6	Temperature	36 / 3	0	30.4	12.7	0	NA / NA	7	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	>1 Acute / Chronic Violation	Assessment Type	Support Level
10630003	6	Aluminum	14 / 3	12	1.6	0.4	0 / 0	NO	Monitored	Full
10630003	6	Arsenic	13 / 3	2	1.19	1.1	0 / 0	NO	Monitored	Full
10630003	6	Cadmium	13 / 3	0.15	0.07	0.02	0 / 0	NO	Monitored	Full
10630003	6	Chromium	13 / 3	1	0.57	0.59	0 / 0	NO	Monitored	Full
10630003	6	Lead	13 / 3	0.31	0.15	0.15	0 / 0	NO	Monitored	Full
10630003	6	Nickel	13 / 3	8.6	4.4	4.1	0 / 0	NO	Monitored	Full
10630003	6	Silver	13 / 3	2.3	0.2	0.025	0 / 0	NO	Monitored	Full
10630003	6	Zinc	13 / 3	2.9	1.7	1.8	0 / 0	NO	Monitored	Full

Class BWW1 - 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
1150	7/20/17	336	40a	MS	Hess	54	Fair	41	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Pass (1/1)	Full
Overall	Evaluated	Pass	Full	1	Assessment was evaluated because it was based on a single sample.

Class BWW1 – Fishkill Assessment:

The Class BWW1 use previously resided in IR Category 3b based on the assessment developed for the 2010 fish kill. Because no additional fish kills were reported in this segment for at least 10 years post fish kill (2020), the IR Category for the fish kill assessment was changed from 3b to 3a (not assessed). DNR believes that any impact from the fish kill from which the impairment was based has likely dissipated.

Details about the 2010 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/824.

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

1/2/2018	Fixed Monitoring Start Date
12/1/2020	Fixed Monitoring End Date
7/20/2017	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

White Breast Creek IA 04-LDM-1059

Assessment Summary

Assessment Explanation

Assessment Key Dates

Methods