Rock Creek IA 01-MAQ-3

from unnamed tributary in SW 1/4 NE 1/4 S30 T81N R6E Clinton Co. (upstream from PCS Nitrogen) to unnamed tributary in S23T81NR5E Clinton 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
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Cycle: 2020
Release Status: Final
Overall IR: 1 - All designated uses are met.
Trend: Stable
Created: 9/11/2020 12:47:05 PM
Updated: 10/13/2020 10:32:33 AM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Fully Supported

Class BWW2

Aquatic Life - Warm Water Type 2

Fully Supported

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 use was assessed as "fully supported" based on water quality monitoring data. The Class BWW2 use was assessed as "fully supported" based on water quality monitoring data.

Assessment Explanation

Sources of Data:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
LTRMP	17	WQ	CY 2016-2018	99990002	Rock Creek, Camanche	Rock Creek above PCS-Nitrogen (Site RK03.7M) is located at County Road Z40, approximately 1.5 miles upstream from the former PCS-Nitrogen facility

Presumptive Class A1 - Indicator Bacteria: No Data

Presumptive 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
99990002	17	42 / 3	8.3	7.6	7.7	0	0%	No	Monitored	Full

Class BWW2 - 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
99990002	17	Ammonia	42 / 3	0.281	0.04	0.02	0 / 0	0% / 0%	No	Monitored	Full
99990002	17	Dissolved oxygen	42 / 3	17.4	10.9	10.3	NA / 0	NA / 0%	No	Monitored	Full
99990002	17	pH	42 / 3	8.3	7.6	7.7	0 / NA	0% / NA	No	Monitored	Full
99990002	17	Temperature	42 / 3	22.3	13.3	14.8	0 / 0	0% / 0%	No	Monitored	Full

Monitoring and Methods

Assessment Key Dates

1/11/2016

Fixed Monitoring Start Date

11/5/2018

Fixed Monitoring End Date

Methods

210

Fixed station physical/chemical monitoring (conventional pollutants only)

222

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