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
- 2020
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Stable
- Created
- 9/15/2020 8:11:20 AM
- Updated
- 10/14/2020 1:50:22 PM
Assessment Summary
The Class A1 use was assessed as "partially supported" based on levels of indicator bacteria (E. coli) that violated state water quality criteria. The Class BWW1 use remains assessed as "partially supported" based on biological sampling data. The Class HH use remains assessed as “partially supported” based on fish tissue sampling data and due to the existence of a one meal per week mercury fish consumption advisory.
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 10460001 West Fork Des Moines River near Humboldt Iowa DNR 6 BIO See Below 933 West Fork Des Moines River Humboldt Iowa DNR 6 FT See Below 136 West Fork Des Moines River SE of Bradgate Iowa DNR 6 FT See Below 276 West Fork Des Moines River Gotch Park - Humboldt
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 10460001 6 21 / 3 171.38 111.24 138.39 Yes 7 33% Yes Monitored Partial Class A - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10460001 6 36 / 3 8.5 8.1 8.2 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 10460001 6 Ammonia 36 / 3 0.95 0.07 0.02 0 / 0 0% / 0% No Monitored Full 10460001 6 Chloride 36 / 3 38 25 26 0 / 0 0% / 0% No Monitored Full 10460001 6 Dissolved oxygen 36 / 3 14.2 11 11.1 NA / 0 NA / 0% No Monitored Full 10460001 6 pH 36 / 3 8.5 8.1 8.2 0 / NA 0% / NA No Monitored Full 10460001 6 Sulfate 36 / 3 140 93 96 0 / NA 0% / NA No Monitored Full 10460001 6 Temperature 36 / 3 26 12 12 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 10460001 6 Aluminum 9 / 2 2.8 0.809 0.5 0 / 0 0% / 0% No Evaluated Full 10460001 6 Arsenic 9 / 2 2.8 2.1 2.3 0 / 0 0% / 0% No Evaluated Full 10460001 6 Cadmium 9 / 2 0.025 0.025 0.025 0 / 0 0% / 0% No Evaluated Full 10460001 6 Chromium 9 / 2 1.1 0.7 0.7 0 / 0 0% / 0% No Evaluated Full 10460001 6 Copper 9 / 2 3 1.1 0.9 0 / 0 0% / 0% No Evaluated Full 10460001 6 Lead 9 / 2 0.13 0.06 0.07 0 / 0 0% / 0% No Evaluated Full 10460001 6 Nickel 9 / 2 3.9 2.9 2.8 0 / 0 0% / 0% No Evaluated Full 10460001 6 Selenium 9 / 2 3.7 2 1.8 0 / 0 0% / 0% No Evaluated Full 10460001 6 Zinc 9 / 2 2 1.16 1.1 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 47b BMIBI BIT BMIBI Pass/ Fail 933 9/15/16 2308 47b MS/WW Float ArtSub 51 Fair 62 Fail 933 8/11/16 2308 47b MS/WW Float ArtSub 75 Good 62 Pass 933 9/9/14 2308 47b MS/WW Float ArtSub 49 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 site was larger than the
calibrated range. Class
HH – Fish Tissue Sampling:
Seg ID Site ID Date Species Name Biopart # in sample Hg result Hg violation (>0.3)? Assessment Type Support Level 1220 276 8/2/2011 walleye plug 3 0.143 No Evaluated Full 1222 136 8/24/2010 walleye fillet 3 0.37 Yes Evaluated Partial 1222 136 9/4/2009 walleye fillet 5 0.328 Yes Evaluated Partial A one meal/week consumption advisory for mercury exists on this segment of the West Fork Des Moines River – seeIowa Consumption Advisories The existence of a
mercury consumption advisory for this segment of the West Fork Des Moines
River indicates that the fish consumption use should be assessed as
“partially supporting”. 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 10460001 6 Cadmium 9 / 2 0.025 0.025 0.025 9 No All Non-Detect Full 10460001 6 Chromium 9 / 2 1.1 0.7 0.7 0 No Evaluated Full 10460001 6 Copper 9 / 2 3 1.1 0.9 0 No Evaluated Full 10460001 6 Nickel 9 / 2 3.9 2.9 2.8 0 No Evaluated Full 10460001 6 Selenium 9 / 2 3.7 2 1.8 0 No Evaluated Full 10460001 6 Zinc 9 / 2 2 1.16 1.1 0 No Evaluated Full
Assessment Key Dates
| 9/9/2014 | Biological Monitoring |
| 8/2/2011 | Fish Tissue Monitoring |
| 1/12/2016 | Fixed Monitoring Start Date |
| 12/3/2018 | Fixed Monitoring End Date |
| 8/11/2016 | Biological Monitoring |
| 9/15/2016 | Biological Monitoring |
| 9/4/2009 | Fish Tissue Monitoring |
| 8/24/2010 | Fish Tissue Monitoring |
Methods
| 150 | Monitoring data more than 5 years old |
| 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 |