Unnamed Tributary to Snyder Creek IA 02-IOW-6401
mouth (S36 T79N R6W Johnson Co.) to headwaters in NE1/4 S18 T79N R5W Johnson Co.
- Cycle
- 2024
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:14:10 AM
- Updated
- 1/17/2024 1:04:38 PM
The General Use was assessed as "not supported" due to impacts of poorly-treated wastewater discharged to the stream that resulted in a violation of Iowa’s narrative water quality criteria (IAC 61.3(2)). The basis for assessment is the results of a Use Attainability Analysis (UAA) conducted by Iowa DNR staff in 2006. All other designated uses were "not assessed."
The assessment of support of the general use of this stream segment remains based on results of observations and biological monitoring conducted by DNR staff on September 21, 2006 as part of a UAA for an Unnamed Tributary to Snyder Creek in Johnson County near the outfall of the Sunrise Mobile Home Park WWTP. The following comments from the UAA regarding the predominant substrate of this stream segment are relevant to this assessment (see http://programs.iowadnr.gov/uaa/search.aspx) “There was a layer of approximately 12 inches of “floc” throughout the majority of the assessed reach that had a sewage odor.” These comments suggest poor water quality conditions and potential violations of several of Iowa's narrative water quality standards (IAC 61.3(2)) designed to protect general uses of Iowa's surface waters (e.g., livestock and wildlife watering, aquatic life and non-contact recreation): --such waters shall be free from substances from point source dischargers that will settle to form sludge deposits; --such waters shall be free from floating debris, oil, grease, scum and other materials from wastewater discharges or agricultural practices in amounts sufficient to create a nuisance; --such waters shall be free from materials from wastewater discharges or agricultural practices producing objectionable color, odor, or other aesthetically objectionable conditions; --such waters shall be free from substance attributable to wastewater discharges or agricultural practices in concentrations or combinations which are acutely toxic to human, animal, or plant life. Based on the information from the September 2006 UAA, the general use of this stream segment was assessed as "not supported" due to water quality impacts from poorly-treated domestic sewage. Waters assessed as “not supported” are considered appropriate for addition to Iowa’s Section 303(d) list of impaired waters.