Loch Ayr IA 05-GRA-1381

Ringgold County S30T69NR29W 2 miles N of Mt. Ayr.

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
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Cycle: 2020
Release Status: Final
Overall IR: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trophic: Hypereutrophic
Trend: Unknown
Created: 8/21/2020 3:05:55 PM
Updated: 10/14/2020 2:54:57 PM

Use Support

Class A1

Recreation - Primary contact

Not Assessed

Class BLW

Aquatic Life - Lakes and wetlands

Not Assessed

Class C

Drinking Water -

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 C (drinking water) use remains “fully supported” based on results of atrazine monitoring from 2010-12. All other designated uses are “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 2018-2018	22800002	Loch Ayr

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
22800002	6	3 / 1	8.6	8.4	8.3	0	0%	NA	Evaluated	NA

Class A1 - Lake TSI's

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Median Value	Median TSI Violation	Assessment Type	Support Level
22800002	6	Chlorophyll a TSI	3 / 1	37	75	60	NA	Evaluated	NA
22800002	6	Secchi TSI	3 / 1	50	70	65	NA	Evaluated	NA
22800002	6	Total Phosphorus TSI	3 / 1	57	83	78	NA	NA	NA
22800002	6	Inorganic suspended solids	3 / 1	0.6	0.6	0.6	NA	NA	NA

Class BLW - 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
22800002	6	Ammonia	3 / 1	0.044	0.03	0.03	0 / 0	0% / 0%	NA	Evaluated	NA
22800002	6	Dissolved oxygen	3 / 1	8.6	6.8	6.1	NA / 0	NA / 0%	NA	Evaluated	NA
22800002	6	pH	3 / 1	8.6	8.4	8.3	0 / NA	0% / NA	NA	Evaluated	NA
22800002	6	Temperature	3 / 1	27.2	25.4	26.8	0 / 0	0% / 0%	NA	Evaluated	NA

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
22800002	6	Inorganic nitrogen (nitrate and nitrite)	3 / 1	0.4	0.15	0.02	0	0%	NA	Evaluated	NA

Class C - Toxic Parameters: Syngenta “Iowa Voluntary Atrazine Monitoring Program” from 2010 through 2012

Parameter Name	# Samples / # Years	Maximum Value	Mean Value	% Violations	Number of Non - Detects	Mean Value > Criterion or MCL	Assessment Type	Support Level
Atrazine	25 / 3	0.92	NA	0%	NA	No	Monitored	Full

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

10/5/2010

Fixed Monitoring Start Date

10/2/2012

Fixed Monitoring End Date

5/21/2018

Fixed Monitoring Start Date

8/13/2018

Fixed Monitoring End Date

Methods

270

PWS chemical monitoring (ambient water)