Little Cedar River IA 02-CED-574

mouth (S20 T94N R14W Chickasaw Co.) to the Chickasaw/Floyd county line at W line S6 T95N R14W Chickasaw 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 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.

Open Segment Map
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Cycle: 2020
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 9/1/2020 7:48:55 AM
Updated: 10/16/2020 9:32:01 AM

Use Support

Class A1

Recreation - Primary contact

Partially Supported

Bacteria: Indicator Bacteria- E. coli

Support Level

Partially Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

Geometric mean criterion exceeded

Data Source

TMDL monitoring: Iowa DNR

TMDL Priority

Tier III

Class BWW1

Aquatic Life - Warm Water Type 1

Fully Supported

Class HH

Human Health -

Fully Supported

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 use remains assessed as "partially supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use remains assessed as "fully supported" based on water quality monitoring data. The Class HH use remains assessed as “fully supported” based on fish tissue sampling data.

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2002-2004	11190001	Little Cedar River at Ionia	Station 69
Iowa DNR	6	FT	See Below	191	Little Cedar River	At Chickasaw Park

Class A1 - Indicator Bacteria:

Site ID	Data Source ID	# Samples / # Years	2002-2004 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11190001	6	48 / 3	631	Yes	32	67%	Yes	Evaluated	Partial

Class A1 - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
11190001	6	41 / 3	8.7	8	8.1	0	0%	No	Evaluated	Full

Class BWW1 - Conventional Parameters:

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
11190001	6	Ammonia	41 / 3	0.66	0.08	0.05	0 / 0	0% / 0%	No	Evaluated	Full
11190001	6	Dissolved oxygen	41 / 3	15.4	10.1	9.8	NA / 0	NA / 0%	No	Evaluated	Full
11190001	6	pH	41 / 3	8.7	8	8.1	0 / NA	0% / NA	No	Evaluated	Full
11190001	6	Temperature	41 / 3	25	12.7	15.2	0 / 0	0% / 0%	No	Evaluated	Full

Class HH – Fish Tissue Sampling:

Site ID

Date

Species Name

Biopart

# in sample

chlordane result

chlordane violation (>0.6)?

PCBs result

PCBs violation (>0.2)?

Hg result

Hg violation (>0.3)?

Assessment Type

Support Level

191

10/8/2015

smallmouth bass

plug

0.140

Monitored

Full

191

10/8/2015

golden redhorse

fillet

<0.02

<0.06

0.14

Monitored

Full

Monitoring and Methods

Assessment Key Dates

1/8/2002

Non-fixed Monitoring Start Date

10/8/2015

Fish Tissue Monitoring

12/8/2004

Non-fixed Monitoring End Date

Methods

150

Monitoring data more than 5 years old

220

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

260

Fish tissue analysis

420

Indicator bacteria monitoring