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
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:59 AM
- Updated
- 12/29/2023 1:17:02 PM
Assessment Summary
The Class A1 use was 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 "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
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2020-2022 10250001 South
Raccoon River near Redfield
Iowa DNR 6 BIO See Below 930 South
Raccoon River Nations
Bridge County Park - Stuart Site ID Data Source ID # Samples per Year (2020/ 2021/2022) 2020 Geometric Mean 2021 Geometric Mean 2022 Geometric Mean Violates Annual Geometric Mean? # 2020 SSM violations / SSM Violations needed for impairment # 2021 SSM violations / SSM Violations needed for impairment # 2022 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 10250001 6 8/8/8 330 138 492 YES 3 / 3 2 / 3 4 / 3 YES Mon Not Site ID Data Source ID # Samples / # Years Minimum Value Maximum Value Mean Value # Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10250001 6 36 / 3 7.3 8.6 8.2 0 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value # Violations # Acute / Chronic Violations Violations needed for impairment Violates Significantly >10% Rule? Assessment Type Support Level 10250001 6 Chloride 36 / 3 12 28 19 NA 0 / 0 7 NO Mon Full 10250001 6 Dissolved Oxygen 36 / 3 7.8 14.7 10.9 0 NA / NA 7 NO Mon Full 10250001 6 pH 36 / 3 7.3 8.6 8.2 0 NA / NA 7 NO Mon Full 10250001 6 Sulfate 36 / 3 16 40 28 0 NA / NA 7 NO Mon Full 10250001 6 Temperature 36 / 3 0 29.8 12.5 0 NA / NA 7 NO Mon Full Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations >1 Acute / Chronic Violation Assessment Type Support Level 10250001 6 Ammonia 36 / 3 0.38 0.06 0.02 0 / 0 NO Mon Full 10250001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10250001 6 Chromium 20 / 3 2 0.6 0.5 0 / 0 NO Mon Full 10250001 6 Lead 20 / 3 1 0.91 1 0 / 0 NO Mon Full 10250001 6 Nickel 20 / 3 4 1.49 1.4 0 / 0 NO Mon Full 10250001 6 Selenium 18 / 2 4 1.6 2 0 / 0 NO Mon Full 10250001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10250001 6 Zinc 20 / 3 2.9 0.8 0.5 0 / 0 NO Mon Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47f BMIBI BIT BMIBI Pass/Fail 930 7/17/19 988 47f MS Floating Art Sub 76 Excellent 51 Pass Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (1/1) Full Assessment was evaluated because the
drainage area Overall Evaluated Pass Full 1 of the site is greater than the calibrated
range. 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 Selenium 18 / 2 4 1.6 2 3 NO Mon Full
Class A1 - Indicator Bacteria:
Class A1 – pH:
Class BWW1 - Binomial Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Overall:
Class HH-F - Toxic Parameters:
Assessment Key Dates
1/7/2020 | Monitoring Start |
12/5/2022 | Monitoring End |
7/17/2019 | Biological Monitoring |
Methods
200 | Physical/Chemical Monitoring |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |