Bloody Run IA 01-YEL-433

mouth (Clayton Co.) to west line of S22 T95N R4W Clayton Co.

This is a DRAFT assessment

Draft assessments may change without notice

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 2022 - 2024
Stream/River Water Quality Data	CY 2022 - 2024
Lake Water Quality Data	CY 2020 - 2024
Biological Sampling Data	CY 2020 - 2024*
Fish Kill Data	CY 2020 - 2024
Fish Tissue Sampling Data	CY 2020 - 2024
Continuous Dissolved Oxygen Sampling Data	CY 2020 - 2024
*Biological sites sampled in both 2019 and 2023 were also assessed.

Open Segment Map
View 2026 assessment summary page

Cycle: 2026
Current Phase: Public Comment
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Stable
Created: 10/27/2025 3:09:32 PM
Updated: 1/2/2026 1:53:55 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

Slight

Status

Continuing

Source

Natural

Source Confidence

Moderate

Cycle Added

2010

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Special project/study: Iowa DNR

TMDL Priority

Tier III

Class A2

Recreation - Secondary contact

Fully Supported

Class BCW1

Aquatic Life - Cold Water Type 1

Not Supported

Fish Kill: Caused By Fuel Spill

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Spills/Dumping: Spills From Trucks or Trains

Source Confidence

High

Cycle Added

2022

Impairment Rationale

Potential Impairment

Data Source

Fish kill investigation: Iowa DNR

Biological: low aquatic macroinvertebrate IBI

Support Level

Not Supported

Impairment Code

5b-v - Biological - verified

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2024

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

TMDL Priority

Tier IV

Class HH

Human Health -

Fully Supported

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use was assessed as “not supported” based on levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class A2 use was assessed as “fully supported” based on the same bacteria monitoring data. The Class BCW1 use was assessed as "not supported" based on biological sampling data and "WINOFI" based on the results of a fish kill investigation. The Class HH use was assessed as "fully supported" based on water quality monitoring data.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2022-2024	10220003	Bloody Run Creek near Marquette
Iowa DNR	6	BIO	See Below	1324	Bloody Run Creek	below Beulah Falls
Iowa DNR	6	BIO	See Below	1152	Bloody Run Creek	HWY 18 bridge W of Marquette

Presumptive Class A1 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2022/ 2023/2024)

2022 Geometric Mean

2023 Geometric Mean

2024 Geometric Mean

Violates Annual Geometric Mean?

# 2022 SSM violations / SSM Violations needed for impairment

# 2023 SSM violations / SSM Violations needed for impairment

# 2024 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

10220003

8/8/8

120

3 / 3

2 / 3

YES

MONITORED

NOT

Class A2 - Indicator Bacteria:

Site ID

Data Source ID

# Samples per Year (2022/ 2023/2024)

2022 Geometric Mean

2023 Geometric Mean

2024 Geometric Mean

Violates Annual Geometric Mean?

# 2022 SSM violations / SSM Violations needed for impairment

# 2023 SSM violations / SSM Violations needed for impairment

# 2024 SSM violations / SSM Violations needed for impairment

Violates Annual SSM Significantly >10% Rule?

Assessment Type

Support Level

10220003

12/12/12

1 / 4

0 / 4

MONITORED

FULL

Presumptive Class A1 & Class A2 – 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
10220003	6	35 / 3	7.9	8.6	8.2	0	7	NO	MONITORED	FULL

Class BCW1 - 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
10220003	6	Chloride	36 / 3	10	16	12	NA	0 / 0	7	NO	MONITORED	FULL
10220003	6	Dissolved Oxygen	36 / 3	9.4	15.9	12.7	0	NA / NA	7	NO	MONITORED	FULL
10220003	6	pH	35 / 3	7.9	8.6	8.2	0	NA / NA	7	NO	MONITORED	FULL
10220003	6	Sulfate	36 / 3	10	20	15	0	NA / NA	7	NO	MONITORED	FULL
10220003	6	Temperature	36 / 3	2.4	18.4	10.5	0	NA / NA	7	NO	MONITORED	FULL

Class BCW1 - 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
10220003	6	Ammonia	35 / 3	0.12	0.03	0.02	0 / 0	NO	MONITORED	FULL
10220003	6	Cadmium	18 / 2	0.5	0.5	0.5	0 / 0	NO	MONITORED	FULL
10220003	6	Chromium	18 / 2	6	1.06	0.74	0 / 0	NO	MONITORED	FULL
10220003	6	Copper	18 / 2	4.2	0.7	0.5	0 / 0	NO	MONITORED	FULL
10220003	6	Lead	18 / 2	1	1	1	0 / 0	NO	MONITORED	FULL
10220003	6	Nickel	18 / 2	1.4	0.5	0.4	0 / 0	NO	MONITORED	FULL
10220003	6	Selenium	36 / 3	1	0.5	0.5	0 / 0	NO	MONITORED	FULL
10220003	6	Silver	18 / 2	1	1	1	0 / 0	NO	MONITORED	FULL
10220003	6	Zinc	18 / 2	3.5	0.7	0.5	0 / 0	NO	MONITORED	FULL

Class BCW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	CBI score	CBI Class	CBI BIT	CBI Pass/Fail
1324	7/29/24	10.5	52b	MS	Hess	46	NA	60	Fail
1324	9/25/23	10.5	52b	MS	Hess	41	NA	60	Fail
1324	9/6/22	10.5	52b	MS	Hess	39	NA	60	Fail
1324	9/7/21	10.5	52b	MS	Hess	57	NA	60	Fail
1152	7/15/21	35.0	52b	MS	Hess	57	NA	60	Fail

Overall Assessment:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Monitored	Fail (0/5)	Not	5bv	Assessment was monitored because it was based on two or more samples collected in a five-year period in the last six years.

Class BCW1 – Fish kill Assessment:

The Class BCW1 use assessment based on the 2020 fish kill placed this segment in Category 3b. This assessment was “evaluated” because there was a single fish kill on this segment in the last five years. Segments assessed using “evaluated” assessments are placed in Category 3b and are added to the state list of Waters In Need Of Further Investigation (WINOFI). If no additional fish kills are reported in this segment for a 5-year period (2025), the Category will be changed from 3b to 3a (not assessed).

Details about the 2020 fish kill can be found here:https://programs.iowadnr.gov/fishkill/Events/992

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
10220003	6	Copper	18 / 2	4.2	0.7	0.5	17	NO	MONITORED	FULL
Site ID	Data Source ID	Parameter Name	# Samples per Year (2022/ 2023/2024)	2022 Mean	2023 Mean	2024 Mean	# Non-Detects per Year (2022/ 2023/2024)	Support Level per Year (2022/ 2023/2024)	Assessment Type	Support Level
10220003	6	Selenium	12/12/12	0.542	0.5	0.5	11/12/12	FS/FS/FS	MONITORED	FULL

Monitoring and Methods

Assessment Key Dates

1/6/2022

Monitoring Start

12/3/2024

Monitoring End

9/6/2022

Biological Monitoring

4/20/2020

Fish Kill

9/7/2021

Biological Monitoring

7/15/2021

Biological Monitoring

9/25/2023

Biological Monitoring

7/26/2024

Biological Monitoring

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

200

Physical/Chemical Monitoring

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring