Cedar River IA 02-CED-456

from confluence with McCloud Run (SW 1/4 S16 T83N R7W Linn Co.) to confluence with Bear Cr. in NE 1/4 S21 T84N R8W Linn Co. (includes East West Seminole and Northwest well fields for city of Cedar Rapids water supply).

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: 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
Trend: Unknown

Created: 8/28/2020 10:26:37 AM
Updated: 10/13/2020 6:57:54 AM

Assessment conducted in accordance with Iowa's 2020 IR methodology

Use Support

Class A1

Recreation

Primary contact

Fully Supported

Class BWW1

Aquatic Life

Warm Water Type 1

WINOFI

Further Investigation Needed

Support Level

Water in Need of Further Investigation (WINOFI)

Impairment Code

3b-u - Use potentially biologically impaired based on uncalibrated IBI metrics.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

Low

Cycle Added

2014

Impairment Rationale

Low Biotic Index

Data Source

Biological monitoring: Iowa DNR WQMA

Class C

Drinking Water

Partially Supported

Impairments

Support Level

Partially Supported

Impairment Code

4a - Pollutant-caused impairment. TMDL has been completed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

1998

Impairment Rationale

Significantly > 10% of samples fail to meet criterion

Data Source

Ambient monitoring: Iowa DNR-rivers

Class HH

Human Health

Fully Supported

General Use

General Use water

Not Assessed

Impairment Delistings

Cycle Added	Class	Cause	Data Source	Rationale
2014	Class A1	pH	Ambient monitoring: USGS	New data: WQ improvement (chemical / physical / bacterial)
2014	Class BWW1	pH	Ambient monitoring: USGS	New data: WQ improvement (chemical / physical / bacterial)

Documentation

Assessment Summary

The Class A1 use was assessed as “fully supported” based on pH monitoring data. Since this was the second consecutive cycle that pH data did not violate the pH criteria, the Class A1 pH impairment has been de-listed. The Class BWW1 use was assessed as "partially supported" based on biological sampling data. Additionally, since this was the second consecutive cycle that pH data did not violate the pH criteria, the Class BWW1 pH impairment has been de-listed. The Class C (drinking water) use was assessed as "fully supported” based on water quality monitoring; however, the Class C use will need to be assessed as "fully supported" for the next IR cycle to be moved from IR Category 4a to IR Category 1. The Class HH (fish consumption) use was assessed as "fully supported" based on water quality monitoring data. Note: A TMDL for nitrate in this segment of the Cedar River was prepared by DNR and approved by EPA in January 2007. Thus, the historic nitrate impairment in this segment is appropriate for Category 4a of Iowa’s Integrated Report.

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
USGS	11	WQ	CY 2016-2018	5464420	Cedar River at Blairs Ferry Road at Palo, IA
USGS	11	WQ	CY 2016-2016	5464480	Cedar River at Edgewood Road at Cedar Rapids, IA
CRWW	14	WQ	CY 2016-2018	99990021	Cedar River
Iowa DNR	6	BIO	See Below	951	Cedar River	Cedar Rapids – US1

Class A - pH:

Site ID	Data Source ID	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
5464420	11	27 / 3	8.9	8.1	8.1	0	0%	No	Monitored	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
5464420	11	Ammonia	27 / 3	0.61	0.08	0.02	0 / 0	0% / 0%	No	Monitored	Full
5464420	11	Chloride	11 / 3	26.2	17.07	17.5	0 / 0	0% / 0%	No	Monitored	Full
5464420	11	Dissolved oxygen	27 / 3	15.5	10.8	10.5	NA / 0	NA / 0%	No	Monitored	Full
5464420	11	pH	27 / 3	8.9	8.1	8.1	0 / NA	0% / NA	No	Monitored	Full
5464420	11	Sulfate	11 / 3	34	20	21	0 / NA	0% / NA	No	Monitored	Full
5464420	11	Temperature	27 / 3	26.2	12.1	12.7	0 / 0	0% / 0%	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	% Acute/ Chronic Violations	>1 Acute / Chronic Violation	Assessment Type	Support Level
5464420	11	Chlorpyrifos-methyl	11 / 3	0.005	0.005	0.005	0 / 0	0% / 0%	No	Monitored	Full
5464480	11	Chlorpyrifos-methyl	2 / 1	0.005	0.005	0.005	0 / 0	0% / 0%	No	Evaluated	Full
5464420	11	Dieldrin	11 / 3	0.006	0.006	0.006	0 / 0	0% / 0%	No	Monitored	Full
5464480	11	Dieldrin	2 / 1	0.006	0.006	0.006	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW1 - Biological Sampling:

Benthic Macroinvertebrates:

BioNet Site ID	Date	Drainage Area (mi2)	Ecoregion	Major Drainage/Thermal	BM Sample Gear	BMIBI score	BMIBI Class	47c BMIBI BIT	BMIBI Pass/ Fail
951	10/9/14	6450	47c	MS/WW	Float ArtSub	51	Fair	52	Fail
951	9/19/13	6450	47c	MS/WW	ArtSub	44	Fair	52	Fail
951	9/28/12	6450	47c	MS/WW	ArtSub	41	Fair	52	Fail

Overall Assessment:

Community	Assessment Type	Assessment Result	Support Level	Earned IR Category	Actual IR Category	Reason
Benthic Macroinvertebrates	Evaluated	Fail (0/3)	Partial	3bu	3bu	Assessment is evaluated because the drainage area of the sample site is larger than calibrated range.

Class C - Conventional Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
5464420	11	Chloride	11 / 3	26.2	17.07	17.5	0	0%	No	Monitored	Full
5464420	11	Fluoride	11 / 3	210	179	180	0	0%	No	Monitored	Full
5464420	11	Inorganic nitrogen (nitrate and nitrite)	27 / 3	10.9	5.86	6.02	1	4%	No	Monitored	Full
99990021	14	Inorganic nitrogen (nitrate and nitrite)	153 / 3	12.4	6.6	6.53	12	8%	No	Monitored	Full
The Class C drinking water use was assessed as “fully supported”. Should this segment be assessed as “fully supported” for the next IR cycle, the Class C impairment will be moved from Category 4a to Category 1.

Class C - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	Number of Non – Detects (ND)	Mean Value > Criterion or MCL	Assessment Type	Support Level
5464420	11	Alachlor	11 / 3	0.004	0.004	0.004	11	No	All ND	Full
5464480	11	Alachlor	3 / 1	0.025	0.011	0.004	3	No	All ND	Full
5464420	11	Atrazine	11 / 3	8.14	0.955	0.086	0	No	Monitored	Full
5464480	11	Atrazine	3 / 1	4.16	1.44	0.11	0	No	Evaluated	Full
5464420	11	Carbofuran	11 / 3	0.03	0.03	0.03	11	No	All ND	Full
5464480	11	Carbofuran	2 / 1	0.03	0.03	0.03	2	No	All ND	Full
5464420	11	Simazine	11 / 3	0.004	0.004	0.003	11	No	All ND	Full
5464480	11	Simazine	3 / 1	0.025	0.0152	0.013	2	No	Evaluated	Full

Class HH-FW - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	Number of Non – Detects (ND)	Mean Value > Criterion or MCL	Assessment Type	Support Level
5464420	11	Dieldrin	11 / 3	0.006	0.006	0.006	11	No	All ND	Full
5464480	11	Dieldrin	2 / 1	0.006	0.006	0.006	2	No	All ND	Full

Monitoring and Methods

Assessment Key Dates

9/28/2012

Biological Monitoring

1/5/2016

Fixed Monitoring Start Date

12/26/2018

Fixed Monitoring End Date

9/19/2013

Biological Monitoring

10/9/2014

Biological Monitoring

1/1/2007

TMDL Completed

2/1/2010

TMDL Completed

Methods

150

Monitoring data more than 5 years old

230

Fixed station physical/chemical (conventional plus toxic pollutants)

270

PWS chemical monitoring (ambient water)

315

Regional reference site approach

320

Benthic macroinvertebrate surveys