Skunk River IA 03-SKU-889
mouth to confluence with Big Cr. southeast of Mt. Pleasant in S19 T70N R5W in Henry Co.
- Assessment Cycle
- 2020
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 9/9/2020 10:35:21 AM
- Updated
- 10/16/2020 10:30:29 AM
Assessment Summary
The Class A1 use was assessed as “partially supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data. The Class HH use was assessed as "fully supported" based on fish tissue sampling data and 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 10560002 Skunk River near Augusta Iowa DNR 6 BIO See Below 889 Skunk River Augusta Iowa DNR 6 FT See Below 171 Skunk River NE of Wever Class A1 -
Indicator Bacteria: Site ID Data Source ID # Samples / # Years 2016 Geometric Mean 2017 Geometric Mean 2018 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10560002 6 24 / 3 324.48 255.81 93.55 Yes 8 33% Yes Monitored Partial Class A - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10560002 6 36 / 3 9 8.3 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 10560002 6 Ammonia 36 / 3 1.2 0.11 0.02 0 / 0 0% / 0% No Monitored Full 10560002 6 Chloride 36 / 3 48 23.6 21 0 / 0 0% / 0% No Monitored Full 10560002 6 Dissolved oxygen 36 / 3 16.3 10.6 11 NA / 0 NA / 0% No Monitored Full 10560002 6 pH 36 / 3 9 8.3 8.3 0 / NA 0% / NA No Monitored Full 10560002 6 Sulfate 36 / 3 85 32 30.5 0 / NA 0% / NA No Monitored Full 10560002 6 Temperature 36 / 3 27 13 14 0 / 0 0% / 0% No Monitored Full 5474000 11 Temperature 597 / 3 33 15 16 1 / 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 10560002 6 Aluminum 9 / 2 19 3.391 1.4 0 / 0 0% / 0% No Evaluated Full 10560002 6 Arsenic 9 / 2 3 1.9 2 0 / 0 0% / 0% No Evaluated Full 10560002 6 Cadmium 9 / 2 0.06 0.029 0.025 0 / 0 0% / 0% No Evaluated Full 10560002 6 Chromium 9 / 2 1.1 0.7 0.72 0 / 0 0% / 0% No Evaluated Full 10560002 6 Copper 9 / 2 4.6 1.89 1.5 0 / 0 0% / 0% No Evaluated Full 10560002 6 Lead 9 / 2 0.18 0.102 0.1 0 / 0 0% / 0% No Evaluated Full 10560002 6 Nickel 9 / 2 5.5 3.1 2.9 0 / 0 0% / 0% No Evaluated Full 10560002 6 Selenium 9 / 2 2.7 1.35 1.2 0 / 0 0% / 0% No Evaluated Full 10560002 6 Zinc 9 / 2 3.8 1.43 1.1 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 40a BMIBI BIT BMIBI Pass/ Fail 943 10/6/15 4303 40a MS/WW Hess 63 Good 41 Pass 943 10/8/13 4303 40a MS/WW Hess 45 Fair 41 Pass 943 10/8/13 4303 40a MS/WW ArtSub 36 Fair 41 Fail
Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (2/3) Full 1 1 Assessment
is evaluated because it included samples not collected in the last five years
and 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 10560002 6 Cadmium 9 / 2 0.06 0.029 0.025 8 No Evaluated Full 10560002 6 Chromium 9 / 2 1.1 0.7 0.72 0 No Evaluated Full 10560002 6 Copper 9 / 2 4.6 1.89 1.5 0 No Evaluated Full 10560002 6 Nickel 9 / 2 5.5 3.1 2.9 0 No Evaluated Full 10560002 6 Selenium 9 / 2 2.7 1.35 1.2 0 No Evaluated Full 10560002 6 Zinc 9 / 2 3.8 1.43 1.1 0 No Evaluated Full Class HH – Fish Tissue Sampling: Site ID Date Species Name Biopart # in sample chlordane result chlordane violation (>0.6)? PCBs result PCBs violation (>0.2)? Hg result Hg violation (>0.3)? Assessment Type Support Level 171 9/14/2016 common carp whole 5 0.05 No <0.06 No 0.08 No Monitored Full 171 9/8/2014 common carp whole 3 <0.05 No <0.24 No 0.12 No Monitored Full
Assessment Key Dates
10/8/2013 | Biological Monitoring |
1/4/2016 | Fixed Monitoring Start Date |
12/31/2018 | Fixed Monitoring End Date |
10/6/2015 | Biological Monitoring |
9/8/2014 | Fish Tissue Monitoring |
9/14/2016 | Fish Tissue Monitoring |
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 |