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

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: 6/4/2020 8:55:16 AM
Updated: 10/16/2020 8:48:01 AM

Assessment conducted in accordance with Iowa's 2020 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

General Use

General Use water

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. All other designated uses were "not assessed".

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY2010-2011	11100001	Lime Creek near Brandon	LiCr2
Iowa DNR	6	WQ	CY2010-2011	15100010	Lime Creek	At 290 St.
Iowa DNR	6	WQ	CY2010-2011	15100011	Lime Creek	At Finley Ave.
Iowa DNR	6	BIO	See Below	154	Lime Creek	Lime Creek Park - Brandon

Presumptive Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2010 Geometric Mean	2011 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11100001	6	22 / 2	1426	1874	Yes	21	95%	Yes	Evaluated	Not
15100010	6	22 / 2	1615	1322	Yes	21	95%	Yes	Evaluated	Not
15100011	6	22 / 2	1963	1819	Yes	21	95%	Yes	Evaluated	Not

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	BM Sample Gear	BMIBI score	BMIBI Class	47c BMIBI BIT	BMIBI Pass/ Fail
154	8/2/18	33	47c	MS/WW	Hess	83	Excellent	70	Pass
154	8/17/17	33	47c	MS/WW	Hess	75	Good	70	Pass
154	7/28/16	33	47c	MS/WW	Hess	68	Good	70	Fail

Fish:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage	Riffle Stream?	FIBI score	FIBI Class	47c FIBI BIT	FIBI Pass/ Fail
154	8/2/18	33	47c	MS/WW	Yes	85	Excellent	65	Pass
154	8/17/17	33	47c	MS/WW	Yes	92	Excellent	65	Pass
154	7/28/16	33	47c	MS/WW	Yes	84	Excellent	65	Pass

Overall:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Monitored	Pass (2/3)	Full
Fish	Monitored	Pass (2/2)	Full
Overall	Monitored	Pass	Full	1	1	Assessment is monitored because all samples used were collected in the last five years.

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

5/29/2010

Non-fixed Monitoring Start Date

7/28/2016

Biological Monitoring

7/29/2011

Non-fixed Monitoring End Date

8/17/2017

Biological Monitoring

8/2/2018

Biological Monitoring

Methods

150

Monitoring data more than 5 years old

220

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

315

Regional reference site approach

320

Benthic macroinvertebrate surveys

330

Fish surveys

420

Indicator bacteria monitoring