Cedar River IA 02-CED-449
mouth (S20 T75N R4W Louisa Co.) to confluence with Sugar Cr. in S17 T78N R2W Muscatine Co.
- Assessment Cycle
- 2020
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 8/28/2020 7:23:59 AM
- Updated
- 10/19/2020 9:13:11 AM
Assessment Summary
The Class A1 use was assessed as “partially supported” due to levels of indicator bacteria (E. coli) that exceeded water quality criteria. The Class BWW1 use was assessed as "partially supported” based on biological sampling data. The Class HH use was assessed as “fully supported” based on ambient water quality monitoring data. Note: This segment was not included in the 2010 EPA TMDL for indicator bacteria impairments in nine segments of Cedar River; therefore, this impairment is not covered by the TMDL and is considered appropriate for Category 5a of Iowa's Integrated Report.
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 10700001 Cedar River near Conesville Iowa DNR 6 BIO See Below 849 Cedar River Conesville 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 10700001 6 21 / 3 248.98 58.86 71.89 Yes 5 24% Yes Monitored Partial Class A1 - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 10700001 6 36 / 3 8.9 8.2 8.3 1 3% 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 10700001 6 Ammonia 36 / 3 0.93 0.11 0.02 0 / 0 0% / 0% No Monitored Full 10700001 6 Chloride 36 / 3 53 26 24 0 / 0 0% / 0% No Monitored Full 10700001 6 Dissolved oxygen 36 / 3 14.5 10.5 10.6 NA / 0 NA / 0% No Monitored Full 10700001 6 pH 36 / 3 8.9 8.2 8.3 1 / NA 3% / NA No Monitored Full 10700001 6 Sulfate 36 / 3 60 27 25 0 / NA 0% / NA No Monitored Full 10700001 6 Temperature 36 / 3 26.4 12.8 13.3 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 10700001 6 Aluminum 9 / 2 4.7 1.344 1.2 0 / 0 0% / 0% No Evaluated Full 10700001 6 Arsenic 9 / 2 2.4 1.8 1.7 0 / 0 0% / 0% No Evaluated Full 10700001 6 Cadmium 9 / 2 0.09 0.04 0.025 0 / 0 0% / 0% No Evaluated Full 10700001 6 Chromium 9 / 2 1.2 0.8 0.8 0 / 0 0% / 0% No Evaluated Full 10700001 6 Copper 9 / 2 3.2 1.27 0.98 0 / 0 0% / 0% No Evaluated Full 10700001 6 Lead 9 / 2 0.22 0.094 0.1 0 / 0 0% / 0% No Evaluated Full 10700001 6 Nickel 9 / 2 3.2 2.3 2.2 0 / 0 0% / 0% No Evaluated Full 10700001 6 Selenium 9 / 2 2.8 1.51 1.4 0 / 0 0% / 0% No Evaluated Full 10700001 6 Zinc 9 / 2 2.8 1.35 1.3 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 72d BMIBI BIT BMIBI Pass/ Fail 849 8/27/18 7789 72d MS/WW Float ArtSub 35 Fair 51 Fail 849 10/7/13 7789 72d MS/WW ArtSub 15 Poor 51 Fail Overall Assessment: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/2) Partial 3bu 3bu Assessment is evaluated because the drainage area
of the sampling site is larger than the calibrated range. 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 10700001 6 Cadmium 9 / 2 0.09 0.04 0.025 6 No Evaluated Full 10700001 6 Chromium 9 / 2 1.2 0.8 0.8 0 No Evaluated Full 10700001 6 Copper 9 / 2 3.2 1.27 0.98 0 No Evaluated Full 10700001 6 Nickel 9 / 2 3.2 2.3 2.2 0 No Evaluated Full 10700001 6 Selenium 9 / 2 2.8 1.51 1.4 0 No Evaluated Full 10700001 6 Zinc 9 / 2 2.8 1.35 1.3 0 No Evaluated Full
Assessment Key Dates
8/27/2018 | Biological Monitoring |
1/4/2016 | Fixed Monitoring Start Date |
12/3/2018 | Fixed Monitoring End Date |
10/7/2013 | Biological Monitoring |
Methods
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |