Boyer River IA 06-BOY-1502
from confluence with Willow Cr. (S28 T78N R44W Harrison Co.) to the Harrison-Crawford county line.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 11/1/2023 8:13:02 AM
- Updated
- 12/22/2023 8:52:49 AM
Assessment Summary
The Class A1 use remains assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use remains assessed as "not supported" based on water quality monitoring data (violations of the chronic selenium criteria). The Class HH use was assessed as "fully supported" based on water quality monitoring data.
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 10430001 Boyer
River near Missouri Valley
Iowa DNR 6 BIO See Below 912 Boyer
River Missouri
Valley 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 10430001 6 6/7/4 242 544 386 YES 3 / NA 3 / 3 3 / NA YES Mon 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 10430001 6 36 / 3 7.2 8.6 8.1 0 7 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 10430001 6 Chloride 36 / 3 15 37 23 NA 0 / 0 7 NO Mon Full 10430001 6 Dissolved Oxygen 36 / 3 7.2 13.4 9.9 0 NA / NA 7 NO Mon Full 10430001 6 pH 36 / 3 7.2 8.6 8.1 0 NA / NA 7 NO Mon Full 10430001 6 Sulfate 36 / 3 24 58 40 0 NA / NA 7 NO Mon Full 10430001 6 Temperature 36 / 3 0 27.3 11.5 0 NA / NA 7 NO Mon 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 10430001 6 Ammonia 36 / 3 0.54 0.06 0.02 0 / 0 NO Mon Full 10430001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10430001 6 Chromium 20 / 3 4 1.04 0.61 0 / 0 NO Mon Full 10430001 6 Lead 20 / 3 1 0.9 1 0 / 0 NO Mon Full 10430001 6 Nickel 20 / 3 3.3 2.1 1.8 0 / 0 NO Mon Full 10430001 6 Selenium 18 / 2 8 5 5 0 / 7 YES Mon Not 10430001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10430001 6 Zinc 20 / 3 4.4 1.1 0.5 0 / 0 NO Mon Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47m BMIBI BIT BMIBI Pass/Fail 912 8/13/18 928 47m MO Floating Art Sub 56 Good 54 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (1/1) Full Assessment was evaluated because the
drainage area Overall Evaluated Pass Full 1 of the sample site was larger than the
calibrated range. 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 10430001 6 Selenium 18 / 2 8 5 5 0 NO Mon Full
Class A1 - Indicator Bacteria:
Class A1 – pH:
Class BWW1 - Binomial Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Overall:
Class HH-F - Toxic Parameters:
Assessment Key Dates
| 1/7/2020 | Monitoring Start |
| 12/13/2022 | Monitoring End |
| 8/13/2018 | Biological Monitoring |
Methods
| 200 | Physical/Chemical Monitoring |
| 315 | Regional reference site approach |
| 320 | Benthic macroinvertebrate surveys |
| 420 | Indicator bacteria monitoring |