Mississippi River IA 01-NEM-75

from Lock & Dam 11 at north side of Dubuque (Dubuque Co.) to Lock & Dam 10 at Guttenberg (Clayton 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
View assessment methodology in new window

Cycle: 2020
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 9/16/2020 11:08:21 AM
Updated: 10/14/2020 9:29:39 AM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BWW1

Aquatic Life - Warm Water Type 1

Not Supported

Metals: Aluminum

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

2006

Impairment Rationale

Violations of acute criterion

Data Source

Ambient monitoring: adjacent state

TMDL Priority

Tier IV

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 was assessed as "fully supported" based on water quality monitoring data. The Class BWW1 use was assessed as “not supported” due to violations of the state water quality criteria for aluminum. The Class HH use remains assessed as "fully supported" based fish tissue sampling data and water quality monitoring data.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
IEPA	10	WQ	CY 2016-2018	99990018	Mississippi River	Illinois EPA at station M-13 at L&D 11 at Dubuque, river mile 583
Iowa DNR	6	FT	See Below	144	Mississippi River

Class A1 - Indicator Bacteria: No Data

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
99990018	10	12 / 3	8.8	7.7	7.9	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
99990018	10	Ammonia	10 / 3	0.35	0.11	0.05	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Chloride	13 / 3	22.1	17.4	16.8	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Dissolved oxygen	11 / 3	15.1	10	8.7	NA / 0	NA / 0%	No	Monitored	Full
99990018	10	pH	12 / 3	8.8	7.7	7.9	0 / NA	0% / NA	No	Monitored	Full
99990018	10	Sulfate	13 / 3	42	30.8	29.7	0 / NA	0% / NA	No	Monitored	Full
99990018	10	Temperature	12 / 3	25	15.2	19.3	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
99990018	10	Aluminum	13 / 3	2410	484.8	295	2 / 12	15% / 92%	Yes	Monitored	Not
99990018	10	Arsenic	13 / 3	2.07	1.17	1	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Cadmium	13 / 3	1.5	1.5	1.5	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Chromium	13 / 3	29.1	4.1	2.5	1 / 1	8% / 8%	No	Monitored	Full
99990018	10	Copper	13 / 3	4.5	2.12	1.87	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Cyanide	7 / 2	1.17	0.99	1	0 / 0	0% / 0%	No	Evaluated	Full
99990018	10	Lead	12 / 3	10.8	2.59	1.95	0 / 1	0% / 8%	No	Monitored	Full
99990018	10	Nickel	13 / 3	5.54	2.15	2.2	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Phenol	13 / 3	6.09	4.08	4	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Selenium	13 / 3	2.5	2.31	2.5	0 / 0	0% / 0%	No	Monitored	Full
99990018	10	Zinc	12 / 3	23.3	9.9	8.1	0 / 0	0% / 0%	No	Monitored	Full

Class HH-F - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	Number of Non - Detects	Mean Value > Criterion or MCL	Assessment Type	Support Level
99990018	10	Cadmium	13 / 3	1.5	1.5	1.5	13	No	Monitored	Full
99990018	10	Chromium	13 / 3	29.1	4.1	2.5	4	No	Monitored	Full
99990018	10	Copper	13 / 3	4.5	2.12	1.87	3	No	Monitored	Full
99990018	10	Cyanide	7 / 2	1.17	0.99	1	4	No	Evaluated	Full
99990018	10	Nickel	13 / 3	5.54	2.15	2.2	2	No	Monitored	Full
99990018	10	Phenol	13 / 3	6.09	4.08	4	4	No	Monitored	Full
99990018	10	Selenium	13 / 3	2.5	2.31	2.5	11	No	Monitored	Full
99990018	10	Zinc	12 / 3	23.3	9.9	8.1	2	No	Monitored	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

144

9/18/15

common carp

fillet

<0.02

<0.06

0.15

Monitored

Full

144

8/6/15

largemouth bass

plug

0.124

Monitored

Full

Monitoring and Methods

Assessment Key Dates

3/13/2014

Fixed Monitoring Start Date

9/21/2016

Fixed Monitoring End Date

9/18/2015

Fish Tissue Monitoring

8/6/2015

Fish Tissue Monitoring

Methods

230

Fixed station physical/chemical (conventional plus toxic pollutants)

260

Fish tissue analysis

860

Other Agencies/Organizations provided monitoring data