Silver Creek IA 01-TRK-192
mouth (S16 T94N R5W Clayton Co.) to confluence with unnamed tributary in S32 T95N R5W Clayton 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 8:12:33 AM
- Updated
- 1/16/2024 10:45:28 AM
| Cycle Added | Class | Cause | Data Source | Rationale |
|---|---|---|---|---|
| 2014 | Class BWW2 | Organic Enrichment: Low Dissolved Oxygen | Ambient monitoring: Iowa DNR-rivers | New data: WQ improvement (chemical / physical / bacterial) |
The presumptive Class A1 use was assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW2 use was assessed as "not supported" based on biological sampling data. Note: The Iowa DNR TMDL for biology, sediment, and ammonia for this segment of Silver Creek was approved by U.S. EPA in July 2012. Because not all the impairments identified for this assessment segment were covered by the TMDL (i.e., indicator bacteria), this segment remains impaired and in IR Category 5.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2021-2022 11220014 Silver Creek at 172 ST Site SC04/SiCR1 Iowa DNR 6 BIO See Below 571 Silver Creek Monona– SiCR1 Iowa DNR 6 BIO See Below 973 Silver Creek Luana 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 11220014 6 0/4/6 NA 695 1068 YES NA 4 / NA 5 / NA YES Eval Not 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 11220014 6 10 / 2 7.71 8.39 8.01 0 3 NO Mon Full 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 11220014 6 Dissolved Oxygen 10 / 2 3.43 12.52 7.58 1 NA / NA 3 NO Mon Full 11220014 6 pH 10 / 2 7.71 8.39 8.01 0 NA / NA 3 NO Mon Full 11220014 6 Temperature 10 / 2 7.2 23.8 16.5 0 NA / NA 3 NO Mon Full BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 52b BMIBI BIT BMIBI Pass/Fail 571 8/20/18 27 52b MS/WW Surb 61 Good 61 Pass 571 8/14/14 27 52b MS/WW Surb 55 Fair 61 Fail 973 8/14/14 17 52b MS/WW Surb 44 Fair 61 Fail BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal Riffle Stream? FIBI score FIBI Class 52b FIBI BIT FIBI Pass/Fail 571 8/20/18 27 52b MS/WW NA 44 Fair 52 Fail 571 8/14/14 27 52b MS/WW NA 46 Fair 52 Fail 973 8/14/14 17 52b MS/WW NA 41 Fair 52 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic Macroinvertebrates Evaluated Fail (1/3) Not Assessment was evaluated because the samples used to complete Fish Evaluated Fail (0/3) Not the assessment were not collected in a recent five-year period. Overall Evaluated Fail Not 4a Impairment is covered by 2012 TMDL.
Presumptive Class A1 - Indicator Bacteria:
Presumptive Class A1 - pH:
Class BWW2 - Binomial Parameters:
Class BWW2 - Biological Sampling:
Benthic Macroinvertebrates:
Fish:
Overall: