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
- 2022
- Release Status
- Final
- 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
- 12/22/2021 12:59:23 PM
- Updated
- 12/22/2021 1:02:14 PM
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. All other designated uses were "not assessed." 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 2018-2020 10070004 Black Hawk Creek at Waterloo
CRWQ 23 WQ CY 2018-2020 99990060 Blackhawk Creek
Iowa DNR 6 BIO See Below 1155 Black
Hawk Creek Ridgeway
Ave SW of Waterloo Site ID Data Source ID # Samples per Year (2018/ 2019/2020) 2018 Geometric Mean 2019 Geometric Mean 2020 Geometric Mean Violates Annual Geometric Mean? # 2018 SSM violations / SSM Violations
needed for impairment # 2019 SSM violations / SSM Violations
needed for impairment # 2020 SSM violations / SSM Violations
needed for impairment Violates Annual SSM Significantly >10%
Rule? Assessment Type Support Level 10070004 6 7/8/8 571 302 99 YES 6 / 3 4 / 3 3 / 3 YES Monitored Not 99990060 23 5/5/5 826 159 185 YES 4 / NA 1 / NA 3 / NA NA Evaluated 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 10070004 6 36 / 3 7.1 8.4 8 0 7 NO Monitored Full 99990060 23 14 / 3 7.34 8.44 7.96 0 4 NO Monitored 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 10070004 6 Ammonia 36 / 3 0.025 0.2 0.04 NA 0 / 0 7 NO Monitored Full 10070004 6 Chloride 36 / 3 14 33 21 NA 0 / 0 7 NO Monitored Full 99990060 23 Chloride 15 / 3 12.6 25 20.1 NA 0 / 0 4 NO Monitored Full 10070004 6 Dissolved Oxygen 36 / 3 7.7 13.8 10.4 0 NA / NA 7 NO Monitored Full 99990060 23 Dissolved Oxygen 15 / 3 6.5 12.7 8.6 0 NA / NA 4 NO Monitored Full 10070004 6 pH 36 / 3 7.1 8.4 8 0 NA / NA 7 NO Monitored Full 99990060 23 pH 14 / 3 7.34 8.44 7.96 0 NA / NA 4 NO Monitored Full 10070004 6 Sulfate 36 / 3 8.8 29 17.1 0 NA / NA 7 NO Monitored Full 99990060 23 Sulfate 15 / 3 6.7 27.2 17 0 NA / NA 4 NO Monitored Full 10070004 6 Temperature 36 / 3 0.1 24.8 11.3 0 NA / NA 7 NO Monitored Full 99990060 23 Temperature 15 / 3 9.1 24.4 19.6 0 NA / NA 4 NO Monitored Full 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 Aluminum 14 / 3 4.2 1 0.6 0 / 0 NO Monitored Full 10070004 6 Arsenic 13 / 3 0.96 0.66 0.65 0 / 0 NO Monitored Full 10070004 6 Cadmium 13 / 3 0.11 0.04 0.02 0 / 0 NO Monitored Full 10070004 6 Chromium 13 / 3 1.2 0.8 0.8 0 / 0 NO Monitored Full 10070004 6 Lead 13 / 3 0.24 0.1 0.1 0 / 0 NO Monitored Full 10070004 6 Nickel 13 / 3 2.9 2.2 2.3 0 / 0 NO Monitored Full 10070004 6 Silver 13 / 3 0.025 0.025 0.025 0 / 0 NO Monitored Full 10070004 6 Zinc 13 / 3 4.4 2.3 2.2 0 / 0 NO Monitored Full 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 Overall: 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.
Class A1 - Indicator Bacteria:
Class A – pH:
Class BWW1 - Conventional Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Class
HH – No Data
Assessment Key Dates
1/8/2018 | Fixed Monitoring Start Date |
12/7/2020 | Fixed Monitoring End Date |
11/9/2006 | TMDL Completed |
8/21/2019 | Biological Monitoring |
Methods
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |