Little Sioux River IA 06-LSR-1578
from confluence with Milford Cr. (NW 1/4 S14 T98N R37W Dickinson Co.) to confluence with West Fork Little Sioux R. in S36 T100N R38W Dickinson 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
- Stable
- Created
- 11/1/2023 8:13:04 AM
- Updated
- 12/22/2023 10:11:35 AM
Assessment Summary
The Class A1 use was assessed as "not supported" due to levels of indicator bacteria that violated state water quality criteria. The Class BWW1 was assessed as "not supported” based 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 10300001 Little
Sioux River near Milford
Iowa DNR 6 BIO See Below 63 Little
Sioux River Horseshoe
Bend County Park - Milford Iowa DNR 6 BIO See Below 1148 Little
Sioux River Gravel
Road Bridge W of Milford 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 10300001 6 8/8/7 219 624 558 YES 4 / 3 6 / 3 6 / 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 10300001 6 36 / 3 6.8 8.5 7.9 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 10300001 6 Chloride 36 / 3 11 34 19 NA 0 / 0 7 NO Mon Full 10300001 6 Dissolved Oxygen 36 / 3 5.3 15.3 9.5 0 NA / NA 7 NO Mon Full 10300001 6 pH 36 / 3 6.8 8.5 7.9 0 NA / NA 7 NO Mon Full 10300001 6 Sulfate 36 / 3 26 190 97 0 NA / NA 7 NO Mon Full 10300001 6 Temperature 36 / 3 0 26.8 11 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 10300001 6 Ammonia 36 / 3 0.44 0.07 0.02 0 / 0 NO Mon Full 10300001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10300001 6 Chromium 20 / 3 3 0.92 0.72 0 / 0 NO Mon Full 10300001 6 Lead 20 / 3 1 0.91 1 0 / 0 NO Mon Full 10300001 6 Nickel 20 / 3 3.2 2.2 2 0 / 0 NO Mon Full 10300001 6 Selenium 18 / 2 5 2.5 2 0 / 0 NO Mon Full 10300001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10300001 6 Zinc 20 / 3 13 1.4 0.5 0 / 0 NO Mon Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/Fail 1148 7/19/21 484.0 47b MO Art Sub 53 Good 62 Fail 63 8/4/20 333.4 47b MO Surber 65 Good 62 Pass 1148 8/5/17 484.0 47b MO Floating Art Sub 73 Good 62 Pass Site ID Date Drainage Area (mi2) Ecoregion Major Drainage Riffle Stream? FIBI score FIBI Class 47b FIBI BIT FIBI Pass/Fail 63 8/4/20 333.4 47b MO Yes 51 Good 53 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Monitored Pass (2/3) Full Fish Evaluated Fail (0/1) Not Assessment was
evaluated because the FIBI Overall Evaluated Fail Not 5bt assessment was based
on a single sample. 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 10300001 6 Selenium 18 / 2 5 2.5 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:
Fish:
Overall:
Class HH-F - Toxic Parameters:
Assessment Key Dates
7/19/2021 | Biological Monitoring |
8/4/2020 | Biological Monitoring |
8/15/2017 | Biological Monitoring |
1/8/2020 | Monitoring Start |
12/14/2022 | Monitoring End |
Methods
200 | Physical/Chemical Monitoring |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
330 | Fish surveys |
420 | Indicator bacteria monitoring |