Lime Creek IA 02-CED-524

mouth (SW 1/4 S4 T86N R10W Benton Co.) to confluence with unnamed tributary in S1 T87N R10W Buchanan 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: 12/16/2021 6:58:05 AM
Updated: 12/22/2021 12:36:41 PM

Assessment conducted in accordance with Iowa's 2022 IR methodology

Use Support

Class A1

Recreation

Primary contact

Presumptive Use

Not Supported

Impairments

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

2014

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Special project/study

TMDL Priority

Tier III

Class BWW1

Aquatic Life

Warm Water Type 1

Fully Supported

Class HH

Human Health

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 violated state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and 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
CRWQ	23	WQ	CY 2018-2020	99990091	Lime Creek
Iowa DNR	6	BIO	See Below	154	Lime Creek	Lime Creek Park - Brandon

Presumptive Class - 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

99990091

5/5/5

922

407

275

YES

5 / NA

4 / NA

2 / NA

Evaluated

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
99990091	23	13 / 3	6.73	9.05	7.85	1	4	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
99990091	23	Chloride	15 / 3	14.1	27.3	19.8	NA	0 / 0	4	NO	Monitored	Full
99990091	23	Dissolved Oxygen	15 / 3	7.8	11.3	9	0	NA / NA	4	NO	Monitored	Full
99990091	23	pH	13 / 3	6.73	9.05	7.85	1	NA / NA	4	NO	Monitored	Full
99990091	23	Sulfate	15 / 3	10.2	20.4	15.1	0	NA / NA	4	NO	Monitored	Full
99990091	23	Temperature	15 / 3	9.2	21.3	17.7	0	NA / NA	4	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	47c BMIBI BIT	BMIBI Pass/ Fail
154	9/23/20	32.5	47c	MS	Hess	75	Good	70	Pass
154	7/22/19	32.5	47c	MS	Hess	72	Good	70	Pass
154	8/2/18	32.5	47c	MS	Hess	83	Excellent	70	Pass
154	8/17/17	32.5	47c	MS	Hess	75	Good	70	Pass
154	7/28/16	32.5	47c	MS	Hess	68	Good	70	Fail

Fish:

Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47c FIBI BIT	FIBI Pass/ Fail
154	9/23/20	32.5	47c	MS	Yes	90	Excellent	65	Pass
154	7/22/19	32.5	47c	MS	Yes	90	Excellent	65	Pass
154	8/2/18	32.5	47c	MS	Yes	85	Excellent	65	Pass
154	8/17/17	32.5	47c	MS	Yes	92	Excellent	65	Pass
154	7/28/16	32.5	47c	MS	Yes	84	Excellent	65	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	IR Category	Reason
Benthic Macroinvertebrates	Monitored	Pass (4/5)	Full
Fish	Monitored	Pass (5/5)	Full	1	Assessment was monitored because the assessment used multiple
Overall	Monitored	Pass	Full		samples collected in the last five years.

Class HH – No Data

Monitoring and Methods

Assessment Key Dates

5/17/2018

Non-fixed Monitoring Start Date

7/28/2016

Biological Monitoring

9/29/2020

Non-fixed Monitoring End Date

8/17/2017

Biological Monitoring

8/2/2018

Biological Monitoring

7/22/2019

Biological Monitoring

9/23/2020

Biological Monitoring

Methods

220

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

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

380

Quantitative physical habitat assessment

420

Indicator bacteria monitoring