2016 assessment for West Branch South Cedar Creek

West Branch South Cedar Creek IA 01-TRK-174

mouth (S31 T93N R3W Clayton Co.) to confluence with unnamed tributary in S23 T93N R4W Clayton Co

2016
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 2012 - 2014
Stream/River Water Quality Data	CY 2012 - 2014
Lake Water Quality Data	CY 2010 - 2014
Biological Sampling Data	CY 2010 - 2014*
Fish Kill Data	CY 2010 - 2014
Fish Tissue Sampling Data	CY 2010 - 2014
Continuous Dissolved Oxygen Sampling Data	CY 2010 - 2014
*Biological sites sampled in both 2009 and 2013 were also assessed.

Open Segment Map
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Overall IR

3 - Insufficient data exist to determine whether any designated uses are met.

Trend

Unknown

Created

4/11/2016 3:23:21 PM by

Updated

11/21/2016 2:15:20 PM by

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

WINOFI

Fish Kill: Caused By Animal Waste

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Moderate

303(d) Listing Status

Continuing

Source

Agriculture: Dairies

Source Confidence

N/A

Cycle Added

2006

Impairment Rationale

Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

General Use

General Use water -

Not Assessed

303(d) Delistings for this Cycle

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 (primary contact recreation) uses remain "not assessed" due to the lack of information upon which to base an assessment. The Class B(WW2) aquatic life uses of this stream remain assessed (evaluated) as “partially supported” due to a fish kill in August 2005 (IR 3b). The kill was caused by manure discharge from a dairy feeding operation. The party responsible for the kill was identified. This impairment was appropriate for Category 4d of Iowa’s 2006 through 2010 Integrated Reporting cycles and was moved to IR Category 3b of Iowa’s 2012 Integrated Report. This potential impairment remains in IR Category 3b.

Assessment Explanation

This kill occurred on or before August 19, 2005, and was caused by manure discharged from a dairy feeding operation. The kill began in Section 36 of T93N, R4W and ended in Section 36 of T93N, R3W. Approximately 1.3 miles of stream were affected; South Cedar Creek, a trout stream, did not appear to have been impacted by the event. A total of 2,226 fish were killed with an estimated value of $660. The party responsible for the kill was identified, and IDNR sought and received restitution for the value of the fish killed and the costs incurred by IDNR in the investigation of the kill.

According to DNR's assessment methodology for Section 305(b) reporting, occurrence of a single pollution-caused fish kill during an assessment period indicates "partial support" of the aquatic life uses. If, however, a consent order has been issued to the party responsible for the kill and monetary restitution has been sought for the fish killed, the affected waterbody should be placed in IR Category 4d (impaired but TMDL not required). Thus, this assessment segment was placed in Category 4d of Iowa’s 2006, 2008, and 2010 Integrated Reports. IDNR considers IR 4d fish kill waters with no subsequent kills in at least the five years subsequent to the kill as appropriate for movement to IR categories 2b or 3b (i.e., Iowa’s list of waters in need of further investigation). Thus, this 4d impairment was moved to IR Category 3b of Iowa’s 2012 Integrated Report and remains in IR Category 3b.

Monitoring and Methods

Assessment Key Dates

8/19/2005

Fish Kill

Methods

140

Incidence of spills and/or fish kills