Mississippi River IA 01-NEM-62

from Lock &Dam 15 at Davenport (Scott Co.) to Lock & Dam 14 at Le Claire (Scott Co.) (= Pool 15) (Davenport water supply intake is located near river mile 484.)

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 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2024
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 11/1/2023 8:13:12 AM
Updated: 2/2/2024 10:26:50 AM

Use Support

Class A1

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- fecal coliform

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2016

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Ambient monitoring: adjacent state

TMDL Priority

Tier IV

Class BWW1

Aquatic Life - Warm Water Type 1

Fully Supported

Class C

Drinking Water -

Fully Supported

Class HH

Human Health -

Not Supported

Fish Consumption Advisory: PCBs

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Moderate

Status

Continuing

Source

Industrial

Source Confidence

Moderate

Cycle Added

2016

Impairment Rationale

Fish consumption advisory in effect: no more than 1 meal/week

Data Source

Fish contaminant monitoring: federal agency

TMDL Priority

Tier IV

Impairment Delistings

Cycle Added	Class	Cause	Data Source	Rationale
2006	Class BWW1	Metals: Aluminum	Ambient monitoring: adjacent state	New data: WQ improvement (chemical / physical / bacterial)

Documentation

Assessment Summary

The Class A1 use remains assessed as "not supported" due to high levels of indicator bacteria (fecal coliforms) reported by the Illinois EPA. The Class BWW1 use was assessed as "fully supported" based on water quality monitoring data. The Class C use was assessed as “fully supported” based on water quality monitoring data and drinking water compliance monitoring required by the DNR. The Class HH use was assessed as "not supported” due to high levels of PCBs in fish tissue and the existing of a one meal per week consumption advisory. The results of interstate consultation via the UMRBA Water Quality Task Force were also used to develop this assessment.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
IEPA	10	WQ	CY 2020-2022	99990016	Mississippi River
PWS	27	WQ	CY 2020-2022	99990181	Mississippi River	Iowa-American Water Co - Davenport
Iowa DNR	6	FT	See Below	1047	Mississippi River	at Davenport

Class A1 - Indicator Bacteria:

The Class A1 use remains assessed as “not supported” based on the impairment of primary contact recreation use identified for this segment of the Upper Mississippi River by the Illinois EPA for the 2016 IR cycle. The Illinois EPA identified an impairment of primary contact recreation use in this river segment due to high levels of indicator bacteria (fecal coliforms). This assessment was developed as a result of interstate consultation on Section 303(d) listing conducted through the Upper Mississippi River Basin Association’s “Water Quality Task Force.”

Class A1 – 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
99990016	10	13 / 2	7.5	8.5	7.9	0	4	NO	Mon	Full
99990181	27	1096 / 3	7.4	9.1	8.1	13	123	NO	Mon	Full

Class BWW1 - Binomial 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
99990016	10	Chloride	22 / 3	12.3	23.6	18.1	NA	0 / 0	5	NO	Mon	Full
99990016	10	Dissolved Oxygen	13 / 2	6.2	14.6	10.4	0	NA / NA	4	NO	Mon	Full
99990016	10	pH	13 / 2	7.5	8.5	7.9	0	NA / NA	4	NO	Mon	Full
99990181	27	pH	1096 / 3	7.4	9.1	8.12	13	NA / NA	123	NO	Mon	Full
99990016	10	Sulfate	22 / 3	11.8	46.7	23.1	0	NA / NA	5	NO	Mon	Full
99990016	10	Temperature	13 / 2	0.6	26.6	13	0	NA / NA	4	NO	Mon	Full
99990181	27	Temperature	1094 / 3	0.8	28.9	14.03	0	NA / NA	123	NO	Mon	Full

Class BWW1 - 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
99990016	10	4,4-DDT	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Aldrin	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Aluminum	22 / 3	750	380.9	325	0 / 0	NO	Mon	Full
99990016	10	Ammonia	12 / 2	0.24	0.09	0.05	0 / 0	NO	Mon	Full
99990181	27	Ammonia	107 / 3	0.231	0.07	0.06	0 / 0	NO	Mon	Full
99990016	10	Arsenic	22 / 3	1.81	0.89	0.94	0 / 0	NO	Mon	Full
99990016	10	Cadmium	22 / 3	1.5	1.5	1.5	0 / 0	NO	Mon	Full
99990016	10	Chloropyrifos	22 / 3	0.05	0.05	0.05	0 / 0	NO	Mon	Full
99990016	10	Chromium	22 / 3	2.5	1.1	0.7	0 / 0	NO	Mon	Full
99990016	10	Copper	22 / 3	2.5	2.4	2.5	0 / 0	NO	Mon	Full
99990016	10	Cyanide	22 / 3	1	0.89	1	0 / 0	NO	Mon	Full
99990016	10	Dieldrin	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Endrin	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	gamma-BHC (Lindane)	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Heptachlor	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Heptachlor epoxide	22 / 3	0.005	0.005	0.005	0 / 0	NO	Mon	Full
99990016	10	Lead	22 / 3	2.5	2.4	2.5	0 / 0	NO	Mon	Full
99990016	10	Nickel	22 / 3	2.5	1.5	1.1	0 / 0	NO	Mon	Full
99990016	10	Parathion	22 / 3	0.05	0.05	0.05	0 / 0	NO	Mon	Full
99990016	10	Pentachlorophenol (PCP)	22 / 3	0.2	0.2	0.2	0 / 0	NO	Mon	Full
99990016	10	Polychlorinated Biphenyls (PCBs)	22 / 3	0.05	0.05	0.05	0 / 0	NO	Mon	Full
99990016	10	Selenium	22 / 3	2.5	2.5	2.5	0 / 0	NO	Mon	Full
99990016	10	Silver	22 / 3	1.5	1.5	1.5	0 / 0	NO	Mon	Full
99990016	10	Toxaphene	22 / 3	0.5	0.5	0.5	0 / 0	NO	Mon	Full
99990016	10	Zinc	22 / 3	5	3.2	2.5	0 / 0	NO	Mon	Full

Class C - Binomial Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	Median Value	# Violations	Violates Significantly >10% Rule?	Assessment Type	Support Level
99990016	10	Chloride	22 / 3	12.3	23.6	18.1	18.2	0	NO	Mon	Full
99990016	10	Fluoride	22 / 3	50	150	110	115	0	NO	Mon	Full
99990181	27	Fluoride	101 / 3	90	390	225	220	0	NO	Mon	Full
99990016	10	Inorganic nitrogen (nitrate and nitrite)	22 / 3	0.28	2.32	1.48	1.47	0	NO	Mon	Full
99990181	27	Nitrate	108 / 3	0.1	5.06	2.3	2.42	0	NO	Mon	Full
99990016	10	pH	13 / 2	7.5	8.5	7.9	8	0	NO	Mon	Full
99990181	27	pH	1096 / 3	7.42462	9.11286	8.12	8.11	13	NO	Mon	Full

Class C - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples per Year (2020/ 2021/2022)	2020 Mean	2021 Mean	2022 Mean	# Non-Detects per Year (2020/ 2021/2022)	Support Level per Year (2020/ 2021/2022)	Assessment Type	Support Level
99990016	10	2,4,5-TP (Silvex)	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Alachlor	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Atrazine	7/9/6	0.083	0.066	0.102	6/5/5	Full/Full/Full	Mon	Full
99990016	10	Beryllium	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Cadmium	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Chromium	7/9/6	1.51	1.761	2.015	0/0/4	Full/Full/Full	Mon	Full
99990016	10	Dalapon	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Dinoseb	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Glyphosate	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Lead	7/9/6	1.736	1.829	2.328	0/2/5	Full/Full/Full	Mon	Full
99990016	10	Picloram	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Silver	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Simazine	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full

Class C - Iowa Drinking Water Compliance Report:

Compliance monitoring required by the Iowa DNR Water Supply Operations and Engineering Sections did not show violations of finished water caused by source water at the Iowa-American Water Co-Davenport facility during the 2020-22 monitoring period. The results of compliance monitoring as reported in annual compliance reports are available at the following location at the Iowa DNR’s home page: https://www.iowadnr.gov/Environmental-Protection/Water-Quality/Water-Supply-Engineering/Annual-Compliance-Report.

Class HH-FW - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples per Year (2020/ 2021/2022)	2020 Mean	2021 Mean	2022 Mean	# Non-Detects per Year (2020/ 2021/2022)	Support Level per Year (2020/ 2021/2022)	Assessment Type	Support Level
99990016	10	2,4-D	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	4,4-DDD	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	4,4-DDE	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	4,4-DDT	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Aldrin	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Barium	7/9/6	46.814	48.989	50.783	0/0/0	Full/Full/Full	Mon	Full
99990016	10	Copper	7/9/6	2.071	0	0	5/9/6	Full/Full/Full	Mon	Full
99990016	10	Cyanide	7/9/6	0.74	0.927	0	3/8/6	Full/Full/Full	Mon	Full
99990016	10	Dieldrin	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Endrin	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	gamma-BHC (Lindane)	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Heptachlor	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Heptachlor epoxide	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Hexachlorobenzene	7/9/6	0	0	0	7/6/6	Full/Full/Full	Mon	Full
99990016	10	Methoxychlor	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Nickel	7/9/6	2.326	2.67	0	0/2/6	Full/Full/Full	Mon	Full
99990016	10	Pentachlorophenol (PCP)	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Polychlorinated Biphenyls (PCBs)	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Selenium	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Toxaphene	7/9/6	0	0	0	7/9/6	Full/Full/Full	Mon	Full
99990016	10	Zinc	7/9/6	9.48	5.538	0	2/7/6	Full/Full/Full	Mon	Full

Class HH - Fish Tissue Sampling:

Site ID	Biopart	Year	Species	# in sample / # of samples	Avg Length (cm)	(Avg) Hg (ppm)	Chlordane (ppm)	Sum PCBs (ppm)
1047	fillet	2018	channel catfish	2	44.4		0.025	0.07
1047	fillet	2018	common carp	2	48.4		0.02	0.06
1047	fillet	2018	common carp	3	67.3		0.023	0.12
1047	tissue plug	2017	largemouth bass	3	33.1	0.147
1047	tissue plug	2016	white bass	5	37.1	0.222
Support Level	Not	A one meal/week PCBs consumption advisory for common carp >20" exists on this segment. Based on IR Methodology, the Class HH (fish consumption) use was assessed as “not supported.”

Monitoring and Methods

Assessment Key Dates

1/1/2020

Monitoring Start

12/31/2022

Monitoring End

10/17/2016

Fish Tissue Monitoring

10/1/2018

Fish Tissue Monitoring

8/9/2017

Fish Tissue Monitoring

Methods

200

Physical/Chemical Monitoring

260

Fish tissue analysis

860

Other Agencies/Organizations provided monitoring data