Honey Creek IA 01-MAQ-6560

from Rutherford Branch (T90N R5W Sec26 Delaware Co.) to headwaters (T90N R5W Sec2 Delaware 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 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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Cycle: 2016
Release Status: Final
Overall IR: 5 - Water is impaired or threatened and a TMDL is needed.
Trend: Declining
Created: 2/25/2016 9:46:37 AM
Updated: 5/5/2020 11:13:44 AM

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

Low

Cycle Added

2014

Impairment Rationale

Geometric mean criterion exceeded

Data Source

Special project/study: Iowa DNR

TMDL Priority

Tier III

Class BWW1

Presumptive Use

Aquatic Life - Warm Water Type 1

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 (primary contact recreation) uses are assessed (monitored) as “not supported” (IR 5p) due to violations of Iowa water quality criteria for indicator bacteria. The Class B(WW1) aquatic life uses remain “not assessed” (IR 3a) due to the lack of water quality information upon which to base an assessment. The source of data for this assessment is the results of monitoring at two sites conducted as part of a Clean Water Act Section 319 water quality project from April through July 2014: (1) STORET station 15280018: Honey Creek at 200th Ave (Site Honey Creek 5) and (2) STORET station 15280020: Honey Creek at Jet Rd (Site Honey Creek 7).

Assessment Explanation

The presumptive Class A1 uses are assessed (monitored) as “not supported" (IR 5p) due to levels of indicator bacteria (E. coli) that exceed the Class A1 geometric mean criterion. The geometric means of indicator bacteria (E. coli) in the eight samples collected at Honey Creek 5 during the recreational season of 2014 was 3,684 orgs/100 ml. All nine samples exceeded the Class A1 single sample maximum criterion of 235 orgs/100 ml. The geometric mean of indicator bacteria (E. coli) in the eight samples collected at Honey Creek 7 during the recreational season of 2014 was 3,338 orgs/100 ml. Again all eight samples exceeded the Class A1 single sample maximum criterion of 235 orgs/100 ml.

Both of these recreation season geometric means far exceed Iowa’s Class A1 geometric mean criterion of 126 E. coli orgs/100 ml, thus indicating nonsupport of the Class A1 primary contact recreation uses. According to U.S. EPA guidelines for Section 305(b) reporting and DNR’s assessment/listing methodology, if a recreation season geometric mean is greater than the respective criterion (126 orgs/100 ml for Class A1, the primary contact recreation uses should be assessed as "not supported" (see pgs 3-33 to 3-35 of U.S. EPA 1997b). In addition, the percentages of samples with levels of E. coli that exceeded Iowa single-sample maximum criteria indicate impairment of Class A1 uses at this monitoring site.

Monitoring and Methods

Assessment Key Dates

4/1/2014

Fixed Monitoring Start Date

7/15/2014

Fixed Monitoring End Date

Methods

420

Indicator bacteria monitoring