East Nishnabotna River IA 05-NSH-1415
from confluence with Fisher Cr. (S27 T69N R40W Fremont Co.) to Page/Montgomery 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
- 9/17/2020 1:30:41 PM
- Updated
- 10/19/2020 8:43:32 AM
Assessment Summary
The Class A1 use remains assessed as "partially supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "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 2016-2018 10360001 East Nishnabotna River near Shenandoah
(US1) Iowa DNR 6 BIO See Below 221 East Nishnabotna River Shenandoah
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 10360001 6 24 / 3 991 772 561 Yes 17 71% Yes Evaluated Partial 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 10360001 6 36 / 3 8.6 8.1 8.2 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 10360001 6 Ammonia 36 / 3 0.31 0.04 0.02 0 / 0 0% / 0% No Monitored Full 10360001 6 Chloride 36 / 3 41 14 13 0 / 0 0% / 0% No Monitored Full 10360001 6 Dissolved oxygen 36 / 3 14.5 10.2 9.9 NA / 0 NA / 0% No Monitored Full 10360001 6 pH 36 / 3 8.6 8.1 8.2 0 / NA 0% / NA No Monitored Full 10360001 6 Sulfate 36 / 3 40 22 22 0 / NA 0% / NA No Monitored Full 10360001 6 Temperature 36 / 3 29.3 14.1 13.7 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 10360001 6 Aluminum 9 / 2 13 4.48 2.2 0 / 0 0% / 0% No Evaluated Full 10360001 6 Arsenic 9 / 2 3.2 2.2 2.1 0 / 0 0% / 0% No Evaluated Full 10360001 6 Cadmium 9 / 2 0.26 0.055 0.025 0 / 0 0% / 0% No Evaluated Full 10360001 6 Chromium 9 / 2 1.7 0.67 0.6 0 / 0 0% / 0% No Evaluated Full 10360001 6 Copper 9 / 2 1.7 0.99 0.87 0 / 0 0% / 0% No Evaluated Full 10360001 6 Lead 9 / 2 0.15 0.082 0.08 0 / 0 0% / 0% No Evaluated Full 10360001 6 Nickel 9 / 2 5 2.6 2.1 0 / 0 0% / 0% No Evaluated Full 10360001 6 Selenium 9 / 2 3.6 2.2 2.1 0 / 0 0% / 0% No Evaluated Full 10360001 6 Zinc 9 / 2 3.5 1.5 0.8 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 47e BMIBI BIT BMIBI Pass/ Fail 221 9/6/16 1022 47e MO/WW Float ArtSub 44 Fair 54 Fail 221 8/17/15 1022 47e MO/WW ArtSub 57 Good 54 Pass 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 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 10360001 6 Cadmium 9 / 2 0.26 0.055 0.025 7 No Evaluated Full 10360001 6 Chromium 9 / 2 1.7 0.67 0.6 0 No Evaluated Full 10360001 6 Copper 9 / 2 1.7 0.99 0.87 0 No Evaluated Full 10360001 6 Nickel 9 / 2 5 2.6 2.1 0 No Evaluated Full 10360001 6 Selenium 9 / 2 3.6 2.2 2.1 0 No Evaluated Full 10360001 6 Zinc 9 / 2 3.5 1.5 0.8 0 No Evaluated Full
Assessment Key Dates
8/17/2015 | Biological Monitoring |
9/6/2016 | Biological Monitoring |
1/7/2014 | Fixed Monitoring Start Date |
12/6/2016 | Fixed Monitoring End Date |
1/4/2016 | Fixed Monitoring Start Date |
12/4/2018 | Fixed Monitoring End Date |
Methods
150 | Monitoring data more than 5 years old |
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |