North Fork Yellow River IA 01-YEL-448
mouth (S13 T96N R7W Winneshiek Co.) to confluence with unnamed tributary in S3 T96N R7W Winneshiek 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 8:14:06 AM
- Updated
- 2/6/2024 1:22:04 PM
The presumptive Class A1 use remains assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use remains assessed as "not supported" due to violations of criteria for dissolved oxygen. Based on DNR's assessment methodology, two consecutive assessment/listing cycles without significantly greater than 10% of the samples violating the standard are necessary to justify the de-listing of the impairment due to low dissolved oxygen. Note: A TMDL for the bacteria impairment for streams in the Yellow River basin was prepared by Iowa DNR in 2012 and was approved by U.S. EPA in February 2013. Due to completion of the TMDL, the Integrated Report category for the Class A1 recreational use was changed from 5p (impaired; TMDL needed) to 4a (impaired; TMDL approved). Because not all impairments identified for this assessment segment are covered by the TMDL (biological impairment of the aquatic life use due to low dissolved oxygen), this segment remains in Category 5a of Iowa's Integrated Report (impaired and TMDL required).
Data
Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2011, 2014 15960034 North Fork Yellow River at 111th Ave Site 1 Site ID Data Source ID # Samples / # Years 2014 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15960034 6 20 / 1 5621 Yes 19 95% Yes Evaluated Not Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations Significantly >10% Violations Assessment Type Support Level 15030011 6 Ammonia 8 / 1 0.25 0.07 0.05 0 / 0 0% / 0% No Evaluated Full 15030011 6 Chloride 14 / 1 33 33 33 0 / 0 0% / 0% No Evaluated Full 15030011 6 Dissolved oxygen 14 / 1 13.6 8.4 7.25 NA / 0 NA / 0% No Evaluated Full 15030011 6 Temperature 14 / 1 22.2 13.8 14.3 0 / 0 0% / 0% No Evaluated Full The
Class BWW2 aquatic life use remains assessed as “not supported” due to
violations of aquatic life criteria for dissolved oxygen at station 15960001
during the 2004-06 monitoring period. Based on DNR's assessment methodology,
two consecutive assessment/listing cycles without significantly greater than
10% of the samples violating the standard are necessary to justify the
de-listing of the impairment due to low dissolved oxygen.
Presumptive Class A1 - Indicator Bacteria: 2014
Class BWW2 - Binomial Parameters: 2011