Turkey River IA 01-TRK-149

from confluence with Volga R. (Clayton Co.) to west line of S9 T93N R5W Clayton Co. (two stream miles downstream from Big Spring Trout Hatchery).

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: 8/10/2020 9:55:06 AM
Updated: 12/3/2021 10:31:30 AM

Use Support

Class A1

Recreation - Primary contact

Not Supported

Bacteria: Indicator Bacteria- E. coli

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

2016

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Watershed project monitoring

TMDL Priority

Tier III

Class BWW1

Aquatic Life - Warm Water Type 1

Fully Supported

Class HH

Human Health -

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class A1 primary contact recreation use was assessed as "not supporting" based on violations of indicator bacteria criteria from 2012-2014. The Class BWW1 aquatic life use remains assessed monitored as "fully supported" based on results of 2012-2014 water quality monitoring. All other designated uses were "not assessed."

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 2012-2014	15220045	Turkey River at HWY 13	TR28

Class A1 - Indicator Bacteria:

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
15220045	6	24 / 3	109	413	62	Yes	7	29%	Yes	Evaluated	Not

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
15220045	6	23 / 3	8.7	8.26	8.26	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
15220045	6	Ammonia	14 / 2	0.21	0.07	0.5	0 / 0	0% / 0%	No	Evaluated	Full
15220045	6	Chloride	16 / 3	33	31.1	31.5	0 / 0	0% / 0%	No	Evaluated	Full
15220045	6	Dissolved Oxygen	21 / 3	12	10.2	10	NA / 0	NA / 0%	No	Evaluated	Full
15220045	6	pH	23 / 3	8.7	8.26	8.26	0 / NA	0% / NA	No	Evaluated	Full
15220045	6	Temperature	24 / 3	25.6	16.6	17.2	0 / 0	0% / 0%	No	Evaluated	Full

Monitoring and Methods

Assessment Key Dates

4/4/2012

Fixed Monitoring Start Date

11/5/2014

Fixed Monitoring End Date

Methods

220

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

420

Indicator bacteria monitoring