Iowa DNR
Iowa DNR
ADBNet
Water Quality Assessments
Impaired Waters List

Unnamed Tributary to Black Hawk Lake (aka Wall Lake Inlet) IA 04-RAC-6635

from confluence with unnamed trib in SW 1/4 S 23 T-86N R-36W Sac Co. to headwaters in NW 1/4 NW 1/4 S7 T-85N R-35W Carroll Co.

Cycle
2016
Release Status
Final
Overall IR
3 - Insufficient data exist to determine whether any designated uses are met.
Trend
Unknown
Created
11/10/2016 4:13:39 PM
Updated
11/15/2016 1:45:05 PM
Use Support
Class A1
Recreation - Primary contact
Not Assessed
Class BWW1
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 and presumptive Class B(WW1) aquatic life uses are considered "not assessed" (IR 3a) due to the lack of monitoring data upon which to base an assessment.  The only water quality data available for the 2012-2014 monitoring period for the 2016 IR cycle are data showing low levels of chloride and sulfate. This parameter coverage is not sufficient for determining support of the presumptive Class B(WW1) aquatic life uses. The source of data for this assessment is the results of monitoring by Iowa DNR at three monitoring stations: (1) station 13140001 (Site BLH-14) at Granite Avenue approximately 1 mile N of Breda monitored from May 2012 to September 2014, (2) station 13810004 at 100th Street (Site BHL-13) approximately 2 miles N of Breda monitored from May 2012 to October 2014, and (3) station 14000119 at 380th Street (Site BHL-09) approximately 4 miles N of Breda.

Assessment Explanation

The presumptive Class A1 uses are considered "not assessed" due to the lack of water quality information upon which to base an assessment.  Monitoring from May 2012 to September 2014 at station 13140001 did not include analysis for indicator bacteria.  

Results of chemical/physical monitoring at station 13140001 show no violations of Class B(WW1) criteria for chloride and sulfate in the 19 samples analyzed. Mean, median, and maximum levels of chloride were 25.4, 26, and 50 mg/l, respectively.  Similarly, results of monitoring at stations 13810004 and 41000119 show no violations of Class B(WW1) criteria for chloride and sulfate. Mean, median, and maximum levels of chloride in the in the 28 samples analyzed at station 13810005 were 38.9, 27.5, and 220 mg/l, respectively.  Mean, median, and maximum levels of chloride in the in the 9 samples analyzed at station 14000119 were 17.2, 13, and 47 mg/l, respectively.  Parameter coverage at these monitoring stations is too limited to allow development of a meaningful water quality assessment of the degree to which the Class B(WW1) aquatic life uses are supported.  

Monitoring and Methods
Assessment Key Dates
5/8/2012
Fixed Monitoring Start Date
10/1/2014
Fixed Monitoring End Date
Methods
240
Non-fixed station physical/chemical (conventional + toxicants)