Black Hawk Creek IA 02-CED-545
mouth (S22 T89N R13W Black Hawk Co.) to Hwy 58 in E 1/2 S27 T88N R14W Black Hawk Co.)
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:53 AM
- Updated
- 2/1/2024 7:15:10 AM
Assessment Summary
The Class A1 use was assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on water quality monitoring data and biological sampling data. The class HH use was assessed as "fully supported" based on water quality monitoring data. Note: A TMDL for indicator bacteria in this segment of Black Hawk Creek was prepared by DNR and approved by EPA in 2006. Because all Section 303(d) impairments identified for this assessment/listing cycle (indicator bacteria) were addressed by the TMDL, this waterbody was placed in IR Category 4a (impaired; TMDL approved) of the current Integrated Report.
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2020-2022 10070004 Black
Hawk Creek at Waterloo
CRWQ 23 WQ CY 2020-2022 99990060 Black
Hawk Creek
Iowa DNR 6 BIO See Below 1155 Black
Hawk Creek Ridgeway
Ave SW of Waterloo 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 10070004 6 8/8/8 99 216 568 YES 3 / 3 4 / 3 6 / 3 YES Mon Not 99990060 23 5/5/5 185 47 103 YES 3 / NA 0 / NA 2 / NA NA Eval WINOFI 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 10070004 6 36 / 3 7.6 8.4 8.1 0 7 NO Mon Full 99990060 23 14 / 3 7.34 8.49 8.13 0 4 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 10070004 6 Chloride 36 / 3 17 30 24 NA 0 / 0 7 NO Mon Full 99990060 23 Chloride 15 / 3 18.5 27.8 22.4 NA 0 / 0 4 NO Mon Full 10070004 6 Dissolved Oxygen 36 / 3 7.5 14 10.6 0 NA / NA 7 NO Mon Full 99990060 23 Dissolved Oxygen 12 / 3 6.5 10 8.5 0 NA / NA 4 NO Mon Full 10070004 6 pH 36 / 3 7.6 8.4 8.1 0 NA / NA 7 NO Mon Full 99990060 23 pH 14 / 3 7.34 8.49 8.13 0 NA / NA 4 NO Mon Full 10070004 6 Sulfate 36 / 3 10 30 19 0 NA / NA 7 NO Mon Full 99990060 23 Sulfate 15 / 3 13.1 27.2 19.1 0 NA / NA 4 NO Mon Full 10070004 6 Temperature 36 / 3 0.1 24.8 11.1 0 NA / NA 7 NO Mon Full 99990060 23 Temperature 15 / 3 5.5 26.3 19.5 0 NA / NA 4 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 10070004 6 Ammonia 36 / 3 0.3 0.05 0.02 0 / 0 NO Mon Full 10070004 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10070004 6 Chromium 20 / 3 4 0.73 0.51 0 / 0 NO Mon Full 10070004 6 Lead 20 / 3 1 0.92 1 0 / 0 NO Mon Full 10070004 6 Nickel 20 / 3 2.3 1.1 0.9 0 / 0 NO Mon Full 10070004 6 Selenium 18 / 2 2 0.9 1 0 / 0 NO Mon Full 10070004 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10070004 6 Zinc 20 / 3 7.6 1.5 0.5 0 / 0 NO Mon Full
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates: Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47c BMIBI BIT BMIBI Pass/Fail 1155 8/21/19 332 47c MS Art Sub 74 Good 52 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (1/1) Full
Overall Evaluated Pass Full 1 Assessment was evaluated
because it was based on a single sample. Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value Number of Non - Detects Mean Value > Criterion or MCL Assessment Type Support Level 10070004 6 Selenium 18 / 2 2 0.9 1 8 NO Mon Full
Overall:
Assessment Key Dates
1/9/2020 | Monitoring Start |
12/8/2022 | Monitoring End |
11/9/2006 | TMDL Completed |
8/21/2019 | Biological Monitoring |
Methods
200 | Physical/Chemical Monitoring |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |
860 | Other Agencies/Organizations provided monitoring data |