Big Sioux River IA 06-BSR-1526
from confluence with Ninemile Cr. (S25 T100N R49W Lyon Co.) to the Iowa / Minnesota state line at N line of S4 T100N R49W Lyon Co.
- Cycle
- 2024
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Stable
- Created
- 11/1/2023 8:13:14 AM
- Updated
- 1/11/2024 8:13:03 AM
The Class A1 use was assessed as “not supported” due to violations of Iowa’s water quality criteria for indicator bacteria (E. coli). The Class BWW1 use was assessed as "fully supported" based on the results of ambient chemical/physical water quality monitoring. All other designated uses were “not assessed.” Note: A TMDL for pathogen indicators in this segment of the Big Sioux River was prepared by DNR and the South Dakota Dept. of Environment & Natural Resources; this TMDL was approved by EPA in January 2008. Because all Section 303(d) impairments identified for the current assessment/listing cycle were addressed by the TMDL, this waterbody remains in IR Category 4a (impaired; TMDL approved).
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description SDAK 16 WQ CY 2020-2022 460831 Big
Sioux River
Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples per Year (2020/ 2021/2022) 2020 Geometric Mean 2021 Geometric Mean 2022 Geometric Mean Violates Annual Geometric Mean? # 2020 SSM violations / SSM Violations needed for impairment # 2021 SSM violations / SSM Violations needed for impairment # 2022 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 460831 16 5/5/5 53 67 193 YES 0 / NA 1 / NA 2 / NA YES Evaluated Not Class A1 - pH Site ID Data Source ID # Samples / # Years Minimum Value Maximum Value Mean Value # Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 460831 16 36 / 3 7.8 9.1 8.4 1 7 NO Mon Full Class BWW1 - Binomial Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value # Violations # Acute / Chronic Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 460831 16 Dissolved Oxygen 35 / 3 5.82 20.19 13.37 0 NA / NA 7 NO Mon Full 460831 16 pH 36 / 3 7.8 9.1 8.4 1 NA / NA 7 NO Mon Full 460831 16 Temperature 36 / 3 0 29.4 12.5 0 NA / NA 7 NO Mon Full Class BWW1 - Toxic Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 460831 16 Ammonia 36 / 3 0.34 0.05 0.02 0 / 0 NO Mon Full
Class HH - No Data