Des Moines River IA 04-UDM-1220
from confluence with East Fork Des Moines R. (S19 T91N R28W Humboldt Co.) to Humboldt Dam at Lake Nokomis at Humboldt.
- Assessment Cycle
- 2022
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 12/27/2021 11:00:47 AM
- Updated
- 1/25/2022 2:44:03 PM
Assessment Summary
The Class A1 use was assessed as "not supported" based on levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use was assessed as "fully supported" based on biological sampling data and on water quality monitoring data. The Class HH (fish consumption) use remains assessed as “not supported” due to the existence of a one meal per week mercury fish consumption advisory in this segment.
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2018-2020 10460001 West Fork Des Moines River near Humboldt
Iowa DNR 6 BIO See Below 933 West
Fork Des Moines River Humboldt Class A1 -
Indicator Bacteria: Site ID Data Source ID # Samples per Year (2018/ 2019/2020) 2018 Geometric Mean 2019 Geometric Mean 2020 Geometric Mean Violates Annual Geometric Mean? # 2018 SSM violations / SSM Violations
needed for impairment # 2019 SSM violations / SSM Violations
needed for impairment # 2020 SSM violations / SSM Violations
needed for impairment Violates Annual SSM Significantly >10%
Rule? Assessment Type Support Level 10460001 6 7/7/8 138 76 84 YES 3 / 3 1 / 3 2 / 3 YES Monitored Not Class A – pH: 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 10460001 6 36 / 3 7.2 8.6 8.1 0 7 NO Monitored Full Class BWW1 -
Conventional Parameters: 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 10460001 6 Ammonia 36 / 3 0.02 0.95 0.08 NA 0 / 0 7 NO Monitored Full 10460001 6 Chloride 36 / 3 9.6 40 21.3 NA 0 / 0 7 NO Monitored Full 10460001 6 Dissolved Oxygen 36 / 3 7.3 14.2 11 0 NA / NA 7 NO Monitored Full 10460001 6 pH 36 / 3 7.2 8.6 8.1 0 NA / NA 7 NO Monitored Full 10460001 6 Sulfate 36 / 3 37 140 81 0 NA / NA 7 NO Monitored Full 10460001 6 Temperature 36 / 3 0 28 11 0 NA / NA 7 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 >1 Acute / Chronic Violation Assessment Type Support Level 10460001 6 Aluminum 14 / 3 2.8 0.6 0.4 0 / 0 NO Monitored Full 10460001 6 Arsenic 13 / 3 2.8 2 1.8 0 / 0 NO Monitored Full 10460001 6 Cadmium 13 / 3 0.07 0.03 0.02 0 / 0 NO Monitored Full 10460001 6 Chromium 13 / 3 1.6 0.8 0.8 0 / 0 NO Monitored Full 10460001 6 Lead 13 / 3 0.28 0.11 0.08 0 / 0 NO Monitored Full 10460001 6 Nickel 13 / 3 5 3.4 3.4 0 / 0 NO Monitored Full 10460001 6 Silver 13 / 3 0.025 0.025 0.025 0 / 0 NO Monitored Full 10460001 6 Zinc 13 / 3 3 1.63 1.6 0 / 0 NO Monitored Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/Fail 933 7/22/20 2308 47b MS Floating Art Sub 64 Good 62 Pass 933 9/15/16 2308 47b MS Floating Art Sub 51 Fair 62 Fail 933 8/11/16 2308 47b MS Floating Art Sub 75 Good 62 Pass Overall: Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Pass (2/3) Full Assessment is evaluated
because the drainage area of the sample site was Overall Evaluated Pass Full 1 greater than the
calibrated range.
Site ID Data Source ID # Days Monitoring (2016/2017/2018/ 2019/2020) DO Criteria Type # 2016 violations /
Violations needed for impairment # 2017 violations /
Violations needed for impairment # 2018 violations
/ Violations needed for impairment # 2019 violations /
Violations needed for impairment # 2020 violations /
Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level
24 hr 0/6 NA NA NA NA No
933 6 29/0/0/0/0 16 hr 0/6 NA NA NA NA No Evaluated Full Support Level Not A one meal/week mercury consumption advisory for any
predator fish exists on this segment. Based on IR Methodology, the Class HH
(fish consumption) use was assessed as “not supported.”
Benthic Macroinvertebrates:
Class BWW1- Continuous DO Monitoring:
Class HH - Fish
Tissue Sampling:
Assessment Key Dates
7/22/2020 | Biological Monitoring |
1/10/2018 | Fixed Monitoring Start Date |
12/9/2020 | Fixed Monitoring End Date |
8/11/2016 | Biological Monitoring |
9/15/2016 | Biological Monitoring |
Methods
222 | Non-fixed-station monitoring (conventional during key seasons and flows) |
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
260 | Fish tissue analysis |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |