Little Volga River IA 01-VOL-328

mouth (north line of S2 T92N R9W Fayette Co.) to Hwy 150 bridge crossing at Maynard at south line of S14 T92N R9W Fayette 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 2018 - 2020
Stream/River Water Quality Data	CY 2018 - 2020
Lake Water Quality Data	CY 2016 - 2020
Biological Sampling Data	CY 2016 - 2020*
Fish Kill Data	CY 2016 - 2020
Fish Tissue Sampling Data	CY 2016 - 2020
Continuous Dissolved Oxygen Sampling Data	CY 2016 - 2020
*Biological sites sampled in both 2015 and 2019 were also assessed.

Open Segment Map
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Cycle: 2022
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Unknown
Created: 1/4/2022 8:31:22 AM
Updated: 1/28/2022 2:56:16 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

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

Watershed project monitoring

TMDL Priority

Tier III

Class BWW1

Aquatic Life - Warm Water Type 1

Not Supported

Fish Kill: Caused By Animal Waste

Support Level

Not Supported

Impairment Code

4d - Pollutant-caused fish kill. No TMDL needed and administrative action taken against responsible party.

Cause Magnitude

Moderate

Status

Continuing

Source

Spills/Dumping: Accidental release/spill

Source Confidence

N/A

Cycle Added

2020

Impairment Rationale

Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

Class HH

Human Health -

Not Supported

Fish Consumption Advisory: Mercury

Support Level

Not Supported

Impairment Code

5a - Pollutant-caused impairment. TMDL needed.

Cause Magnitude

Slight

Status

Continuing

Source

Unknown: Source Unknown

Source Confidence

N/A

Cycle Added

2008

Impairment Rationale

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

Data Source

Fish contaminant monitoring: Iowa DNR

TMDL Priority

Tier IV

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use remains assessed as “not supported” due to violations of Iowa water quality criteria for indicator bacteria (E. coli). The Class BWW1 use was assessed as “not supported” based on a fish kill investigation. The Class HH (fish consumption) use remains assessed as “not supported” due to the existence of a one meal per week consumption advisory for smallmouth bass in this segment.

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2012-2014	15330008	Little Volga R @ Neon Road

Presumptive Class A1 - Indicator Bacteria: Historical

Site ID	Data Source ID	# Samples / # Years	2012 Geometric Mean	2013 Geometric Mean	2014 Geometric Mean	Annual Geometric Mean Violation	# Violations	% Violations	Significantly >10% Violations	Assessment Type	Support Level
15330008	6	23 / 3	2069	784	399	Yes	20	87%	Yes	Evaluated	Not

Class BWW1 - Conventional Parameters: Historical

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
15330008	6	Ammonia	13 / 2	0.2	0.07	0.05	0 / 0	0% / 0%	No	Evaluated	Full
15330008	6	Chloride	19 / 3	39	31.5	30	0 / 0	0% / 0%	No	Evaluated	Full
15330008	6	Dissolved oxygen	23 / 3	12	8.4	8	NA / 0	NA / 0%	No	Evaluated	Full
15330008	6	pH	23 / 3	8.6	8.1	8.1	0 / NA	0% / NA	No	Evaluated	Full
15330008	6	Temperature	22 / 3	26.1	14.5	14.05	0 / 0	0% / 0%	No	Evaluated	Full

Class BWW1 - Fish Kill:

The Class BWW1 use assessment based on the 2017 fish kill placed this segment in Category 4d. The fish kill was caused by a “pollutant” or was suspected to be caused by a “pollutant”; therefore, the Class BWW1 use was considered impaired. However, because restitution for the fish killed was received, the Class BWW1 use was placed in Category 4d (impaired but TMDL not required). DNR feels that (1) TMDLs should not be required for a fish kill caused by a one-time illegal or unauthorized release of a pollutant where enforcement action was taken and (2) enforcement action is more appropriate and effective for addressing a spill-related impairment than the TMDL process.

Details about the 2017 fish kill can be found here: https://programs.iowadnr.gov/fishkill/Events/936

Class HH - Fish Tissue Sampling:

Support Level

Not

A one meal/week mercury consumption advisory for smallmouth bass 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

4/4/2012

Non-fixed Monitoring Start Date

11/5/2014

Non-fixed Monitoring End Date

8/7/2017

Fish Kill

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills

150

Monitoring data more than 5 years old

222

Non-fixed-station monitoring (conventional during key seasons and flows)

260

Fish tissue analysis

420

Indicator bacteria monitoring