Des Moines River IA 04-UDM-1212
from the Interstate 80/35 bridge (S17 T79N R24W Polk Co.) to Saylorville Dam in S30 T80N R24W Polk Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Stable
- Created
- 9/15/2020 6:48:13 AM
- Updated
- 10/13/2020 6:55:32 AM
The presumptive Class A1 use was assessed as "fully supported" based on indicator bacteria monitoring. The Class BWW1 use remains assessed as "partially supported” based on biological sampling data. The Class C (drinking water) use was assessed as "partially supported" based on water quality monitoring data. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data and on water quality monitoring data. Note: A TMDL for nitrate was approved by EPA in September 2009. Because this TMDL covers the nitrate impairment identified for this waterbody, this impairment remains in IR Category 4a (impaired; TMDL approved) for this cycle.
Sources of
Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description USACE 12 WQ CY 2016-2018 17770001 Des Moines River at 66th. St. Iowa DNR 6 BIO See Below 917 Des Moines River Des Moines – US1 Presumptive 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 17770001 12 22 / 2 22.18 NA 20.83 No 2 9% No Monitored Full 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 17770001 12 65 / 3 8.97 8.19 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 17770001 12 Ammonia 65 / 3 1.49 0.12 0.06 0 / 2 0% / 3% No Monitored Full 17770001 12 Dissolved oxygen 65 / 3 15.4 11.1 10.8 NA / 0 NA / 0% No Monitored Full 17770001 12 pH 65 / 3 8.97 8.19 8.2 0 / NA 0% / NA No Monitored Full 17770001 12 Temperature 65 / 3 29.3 16.2 17.9 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 17770001 12 Cadmium 3 / 1 0.15 0.15 0.15 0 / 0 0% / 0% No Evaluated Full 17770001 12 Copper 7 / 2 1.9 1 1.1 0 / 0 0% / 0% No Evaluated Full 17770001 12 Lead 3 / 1 0.5 0.5 0.5 0 / 0 0% / 0% No Evaluated Full 17770001 12 Mercury 3 / 1 0.025 0.0175 0.025 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 917 9/17/14 5840 47b MS/WW Float ArtSub 29 Poor 62 Fail 917 9/24/13 5840 47b MS/WW ArtSub 42 Fair 62 Fail 917 8/17/12 5840 47b MS/WW ArtSub 32 Fair 62 Fail Overall: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/3) Partial 3bu 3bu Assessment is evaluated
because it included samples not collected in the last five years and the
drainage area of the samples site was larger than the calibrated range. Class C -
Conventional Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 17770001 12 Inorganic nitrogen (nitrate and nitrite) 65 / 3 13.8 7.1 7.1 12 18% Yes Monitored Partial Class C - 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 17770001 12 Cadmium 3 / 1 0.15 0.15 0.15 3 No All Non-Detect Full 17770001 12 Lead 3 / 1 0.5 0.5 0.5 3 No All Non-Detect Full Class HH-FW -
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 17770001 12 Copper 7 / 2 1.9 1 1.1 3 No Evaluated Full 17770001 12 Mercury 3 / 1 0.025 0.0175 0.025 3 No All Non-Detect Full
Class HH – Fish
Tissue Sampling: Fish consumption (HH) uses are assessed (monitored) as “fully supported” based on results of water quality and fish contaminant monitoring at ISU/ACOE station 5 (17770001) at Sycamore Access in 2014-2016. Fish contaminant monitoring conducted downstream from Saylorville Reservoir by ISU/ACOE in 2014, 2015 and 2016 showed low levels of pesticide contaminants (dieldrin, chlordane, trifuluralin, and chlorpyrifos) in composite samples of whole fish of common carp. None of the concentrations for chlordane approached Iowa’s thresholds for issuing a one meal per week consumption advisory. Composite samples of whole-fish common carp were analyzed for PCBs in 2016. Levels of PCBs in samples of whole-fish common carp were below levels of detection in 2016. In addition to these pesticide parameters, fillets from smallmouth bass were analyzed for mercury in in 2014 and fillets from largemouth bass were analyzed for mercury in in 2015 and 2016. The results showed that the level of mercury in the 2014 sample from smallmouth bass (0.69 ppm) was above the Hg level of concern (0.3 ppm); however the samples from the 2015 largemouth bass (0.13 ppm) and the 2016 largemouth bass (0.11 ppm) were both below the level of concern. For more information on ISU/ACOE water quality monitoring in this river reach, see the Des Moines River Water Quality Monitoring Network web site is http://home.eng.iastate.edu/~dslutz/dmrwqn/dmrwqn.html.