Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Crane Creek IA 01-TRK-211

from confluence with unnamed tributary (NE 1/4 NW 1/4 S4 T95N R11W Chickasaw Co.) to confluence with Spring Cr. in S17 T98N R12W Howard Co.

Cycle
2016
Release Status
Final
Overall IR
5 - Water is impaired or threatened and a TMDL is needed.
Trend
Unknown
Created
5/6/2016 3:31:16 PM
Updated
9/29/2016 8:24:53 AM
Use Support
Class A1
Recreation - Primary contact
Not Supported
Support Level
Not Supported
Impairment Code
5p - Impairment occurs on a waterbody with a presumptive A1 or B(WW1) use.
Cause Magnitude
Moderate
Status
Continuing
Source
Agriculture
Source Confidence
N/A
Cycle Added
2014
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 presumptive Class A1 (primary contact recreation) uses are assessed (monitored) as “not supported” (IR 5p) due to levels of indicator bacteria that exceed state water quality criteria. The Class B(WW1) aquatic life uses are assessed (monitored) as “fully supported” (IR 2a) based on results of water quality monitoring from April 2012 to November 2014. Fish consumption uses remain "not assessed" (IR 3a) due to the lack of fish contaminant monitoring in this assessment segment. The source of data for this assessment is the results of monitoring from the Turkey River Watershed project from April 2012 to November 2014 at station CRA40 at 120th Street (STORET station 15190001).

Assessment Explanation

The presumptive Class A1 (primary contact recreation) uses are assessed as "not supported" based on levels of indicator bacteria that exceeded state water quality criteria.  Based on the approximately eight monthly samples collected during the recreation seasons of 2012, 2013, and 2014, the geometric means at station CRA-40 are as follow:  601, 1,968, and 486 E. coli orgs/100 ml., respectively.  All three geometric means exceed the Class A1 criterion of 126 orgs/100 ml.  Twenty of the combined 23 samples (87%) exceeded Iowa’s single-sample maximum criterion of 235 orgs/100 ml.  According to U.S. EPA guidelines for Section 305(b) reporting and IDNR’s assessment/listing methodology, if a recreation season geometric mean exceeds the respective water quality criterion, the contact recreation uses should be assessed as "impaired" (see pgs 3-33 to 3-35 of U.S. EPA 1997b).  Thus, because at least one recreation season geometric mean exceeded criteria for Class A1 uses, these uses are assessed as “impaired.” 

Results of chemical/physical water quality monitoring conducted at station CRA-40 from April 2012 to November 2014 show no violations of Class B(WW1) water quality criteria for dissolved oxygen (24 samples), ammonia (16 samples), pH (24 samples), temperature (24 samples), or chloride (16 samples).  Thus, these monitoring results suggest that the Class B(WW1) aquatic life uses should be assessed (monitored) as “fully supported”.

The Class HH (human health/fish consumption) uses remain “not assessed” due to the lack of fish contaminant monitoring in this assessment segment.

Monitoring and Methods
Assessment Key Dates
4/4/2012
Fixed Monitoring Start Date
11/5/2014
Fixed Monitoring End Date
Methods
240
Non-fixed station physical/chemical (conventional + toxicants)
420
Indicator bacteria monitoring