South Raccoon River IA 04-RAC-1181
mouth (S21 T78 R27W Dallas Co.) to confluence with Middle Raccoon R. in S9 T78N R29W near Redfield in Dallas 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
- 9/14/2020 10:10:18 AM
- Updated
- 10/16/2020 12:26:17 PM
Assessment Summary
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 BWW1 use was assessed as "fully supported” based on water quality monitoring data and 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 10250001 South Raccoon River near Redfield Iowa DNR 6 BIO See Below 930 South Raccoon River Redfield 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 10250001 6 22 / 3 597.79 314.39 467.08 Yes 11 50% 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 10250001 6 34 / 3 8.7 8.3 8.4 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 10250001 6 Ammonia 34 / 3 0.88 0.09 0.02 0 / 0 0% / 0% No Monitored Full 10250001 6 Chloride 36 / 3 25 16 16 0 / 0 0% / 0% No Monitored Full 10250001 6 Dissolved oxygen 36 / 3 16.3 10.9 10.6 NA / 0 NA / 0% No Monitored Full 10250001 6 pH 34 / 3 8.7 8.3 8.4 0 / NA 0% / NA No Monitored Full 10250001 6 Sulfate 36 / 3 34 23 22 0 / NA 0% / NA No Monitored Full 10250001 6 Temperature 36 / 3 27.7 13.3 12.7 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 10250001 6 Aluminum 9 / 2 28 3.62 0.4 0 / 0 0% / 0% No Evaluated Full 10250001 6 Arsenic 9 / 2 4.3 2.4 2.3 0 / 0 0% / 0% No Evaluated Full 10250001 6 Cadmium 9 / 2 0.025 0.025 0.025 0 / 0 0% / 0% No Evaluated Full 10250001 6 Chromium 9 / 2 1.1 0.72 0.86 0 / 0 0% / 0% No Evaluated Full 10250001 6 Copper 9 / 2 3 1.17 0.85 0 / 0 0% / 0% No Evaluated Full 10250001 6 Lead 9 / 2 0.11 0.061 0.05 0 / 0 0% / 0% No Evaluated Full 10250001 6 Nickel 9 / 2 4.3 2.7 2.6 0 / 0 0% / 0% No Evaluated Full 10250001 6 Selenium 9 / 2 2.9 2.2 2.2 0 / 0 0% / 0% No Evaluated Full 10250001 6 Zinc 9 / 2 3.7 1.18 0.59 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 47f BMIBI BIT BMIBI Pass/ Fail 930 10/8/15 988 47f MS Float ArtSub 52 Fair 51 Pass 930 9/6/13 988 47f MS Hess 57 Good 51 Pass 930 9/6/13 988 47f MS ArtSub 43 Fair 51 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 10250001 6 Cadmium 9 / 2 0.025 0.025 0.025 9 No All Non-Detect Full 10250001 6 Chromium 9 / 2 1.1 0.72 0.86 0 No Evaluated Full 10250001 6 Copper 9 / 2 3 1.17 0.85 0 No Evaluated Full 10250001 6 Nickel 9 / 2 4.3 2.7 2.6 0 No Evaluated Full 10250001 6 Selenium 9 / 2 2.9 2.2 2.2 0 No Evaluated Full 10250001 6 Zinc 9 / 2 3.7 1.18 0.59 0 No Evaluated Full
Assessment Key Dates
9/6/2013 | Biological Monitoring |
1/6/2016 | Fixed Monitoring Start Date |
12/6/2018 | Fixed Monitoring End Date |
10/8/2015 | Biological 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 |