Boyer River IA 06-BOY-1502
from confluence with Willow Cr. (S28 T78N R44W Harrison Co.) to the Harrison-Crawford county line.
- Assessment Cycle
- 2020
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 9/18/2020 12:03:00 PM
- Updated
- 10/13/2020 2:26:49 PM
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 was assessed as "not supported" based on water quality monitoring data (violations of the chronic selenium criteria) and "partially supported" based on biological sampling data. The Class HH use was assessed as "fully supported" based on water quality monitoring data.
Assessment Explanation
Sources
of Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2014-2016, CY 2016-2018 10430001 Boyer River near Missouri Valley Iowa DNR 6 BIO See Below 912 Boyer River Missouri Valley Class
A1 - Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2014 Geometric Mean 2015 Geometric Mean 2016 Geometric Mean Annual Geometric Mean
Violation # Violations % Violations Significantly >10%
Violations Assessment Type Support Level 10430001 6 24 / 3 487 1138 539 Yes 18 75% Yes Evaluated Not Class
A1 - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10430001 6 35 / 3 8.5 8.2 8.3 0 0% No Monitored Full Class
BWW1 - Conventional Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations Significantly >10% Violations Assessment Type Support Level 10430001 6 Ammonia 35 / 3 0.69 0.06 0.02 0 / 0 0% / 0% No Monitored Full 10430001 6 Chloride 36 / 3 110 20 17 0 / 0 0% / 0% No Monitored Full 10430001 6 Dissolved oxygen 36 / 3 14.3 10.1 10 NA / 0 NA / 0% No Monitored Full 10430001 6 pH 35 / 3 8.5 8.2 8.3 0 / NA 0% / NA No Monitored Full 10430001 6 Sulfate 36 / 3 50 35 35 0 / NA 0% / NA No Monitored Full 10430001 6 Temperature 36 / 3 25.2 12.2 11.5 0 / 0 0% / 0% No Monitored Full Class
BWW1 - Toxic Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 10430001 6 Aluminum 9 / 2 16 4.86 3.8 0 / 0 0% / 0% No Evaluated Full 10430001 6 Arsenic 9 / 2 4.4 2.9 2.5 0 / 0 0% / 0% No Evaluated Full 10430001 6 Cadmium 9 / 2 0.05 0.028 0.025 0 / 0 0% / 0% No Evaluated Full 10430001 6 Chromium 9 / 2 1.4 0.95 1 0 / 0 0% / 0% No Evaluated Full 10430001 6 Copper 9 / 2 2.3 1.22 1.1 0 / 0 0% / 0% No Evaluated Full 10430001 6 Lead 9 / 2 0.23 0.081 0.07 0 / 0 0% / 0% No Evaluated Full 10430001 6 Nickel 9 / 2 5 3 2.7 0 / 0 0% / 0% No Evaluated Full 10430001 6 Selenium 9 / 2 11 6.6 6.1 0 / 8 0% / 89% Yes Evaluated Not 10430001 6 Zinc 9 / 2 9.6 2.05 0.71 0 / 0 0% / 0% No Evaluated Full Class
BWW1 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 47m BMIBI BIT BMIBI Pass/ Fail 912 8/13/18 928 47m MO/WW Float ArtSub 56 Good 54 Pass 912 9/24/14 928 47m MO/WW Float ArtSub 49 Fair 54 Fail Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (1/2) Partial 3bu 3bu Assessment
is evaluated because the drainage area of the sample site was larger than the
calibrated range. Class
HH-F - Toxic Parameters: 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 Cadmium 9 / 2 0.05 0.028 0.025 8 No Evaluated Full 10430001 6 Chromium 9 / 2 1.4 0.95 1 0 No Evaluated Full 10430001 6 Copper 9 / 2 2.3 1.22 1.1 0 No Evaluated Full 10430001 6 Nickel 9 / 2 5 3 2.7 0 No Evaluated Full 10430001 6 Selenium 9 / 2 11 6.6 6.1 0 No Evaluated Full 10430001 6 Zinc 9 / 2 9.6 2.05 0.71 0 No Evaluated Full
Assessment Key Dates
1/5/2016 | Fixed Monitoring Start Date |
12/5/2018 | Fixed Monitoring End Date |
8/13/2018 | Biological Monitoring |
9/24/2014 | Biological Monitoring |
1/7/2014 | Fixed Monitoring Start Date |
12/7/2016 | Fixed Monitoring End Date |
Methods
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |