South Skunk River IA 03-SSK-931
from confluence with Indian Creek (S32 T80N R20W Jasper Co.) to outfall of Ames wastewater treatment plant in SW 1/4 S32 T83N R23W Story 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 1:28:08 PM
- Updated
- 10/16/2020 10:42:53 AM
The Class A1 use was assessed as "partially supported" due to levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW2 use remains assessed as "partially supported" based on biological sampling data.
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 10850002 South Skunk River near Cambridge (DS1) Iowa DNR 6 BIO See Below 286 South Skunk River Cambridge 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 10850002 6 21 / 3 242.75 292.74 564.27 Yes 13 62% Yes Monitored 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 10850002 6 35 / 3 8.5 8.1 8.2 0 0% No Monitored Full Class BWW2 -
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 10850002 6 Ammonia 35 / 3 1.3 0.09 0.02 0 / 0 0% / 0% No Monitored Full 10850002 6 Chloride 36 / 3 81 32 26 0 / 0 0% / 0% No Monitored Full 10850002 6 Dissolved oxygen 36 / 3 13.5 10.2 9.8 NA / 0 NA / 0% No Monitored Full 10850002 6 pH 35 / 3 8.5 8.1 8.2 0 / NA 0% / NA No Monitored Full 10850002 6 Sulfate 36 / 3 97 37.1 29.5 0 / NA 0% / NA No Monitored Full 10850002 6 Temperature 36 / 3 28.4 12.2 12.1 0 / 0 0% / 0% No Monitored Full Class BWW2 -
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 10850002 6 Aluminum 9 / 2 4.5 1.666 1.2 0 / 0 0% / 0% No Evaluated Full 10850002 6 Arsenic 9 / 2 2.3 1.64 1.6 0 / 0 0% / 0% No Evaluated Full 10850002 6 Cadmium 9 / 2 0.05 0.028 0.025 0 / 0 0% / 0% No Evaluated Full 10850002 6 Chromium 9 / 2 1.4 0.88 0.96 0 / 0 0% / 0% No Evaluated Full 10850002 6 Copper 9 / 2 5.2 1.94 1.6 0 / 0 0% / 0% No Evaluated Full 10850002 6 Lead 9 / 2 0.16 0.091 0.09 0 / 0 0% / 0% No Evaluated Full 10850002 6 Nickel 9 / 2 4.9 3.4 3.1 0 / 0 0% / 0% No Evaluated Full 10850002 6 Selenium 9 / 2 2.4 1.42 1.3 0 / 0 0% / 0% No Evaluated Full 10850002 6 Zinc 9 / 2 12 4 2.2 0 / 0 0% / 0% No Evaluated Full Class
BWW2 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/ Fail 286 8/17/16 605 47b MS/WW Float ArtSub 55 Fair 62 Fail 286 7/21/15 605 47b MS/WW Float ArtSub 75 Good 62 Pass 286 10/7/14 605 47b MS/WW Float ArtSub 47 Fair 62 Fail Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (1/3) Partial 3bu 3bu Assessment
is evaluated because the drainage area of the sample site was larger than the
calibrated range.