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
- 2022
- Release Status
- Final
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 12/20/2021 10:25:21 AM
- Updated
- 1/13/2022 7:30:49 AM
Assessment Summary
The Class A1 use was assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded water quality criteria. The Class BWW1 use was assessed as "WINOFI” based on biological sampling data. All other designated uses were "not assessed." 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
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2018-2020 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 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 10700001 6 8/8/8 72 130 59 YES 2 / 3 3 / 3 1 / 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 10700001 6 36 / 3 6.2 8.9 8.2 1 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 10700001 6 Ammonia 36 / 3 0.02 0.93 0.12 NA 0 / 0 7 NO Monitored Full 10700001 6 Chloride 36 / 3 14 53 26 NA 0 / 0 7 NO Monitored Full 10700001 6 Dissolved Oxygen 36 / 3 6.9 14.4 10.7 0 NA / NA 7 NO Monitored Full 10700001 6 pH 36 / 3 6.2 8.9 8.2 1 NA / NA 7 NO Monitored Full 10700001 6 Sulfate 36 / 3 15 60 26 0 NA / NA 7 NO Monitored Full 10700001 6 Temperature 36 / 3 0.1 29.1 12.5 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 10700001 6 Aluminum 14 / 3 6.9 1.3 0.5 0 / 0 NO Monitored Full 10700001 6 Arsenic 13 / 3 2.4 1.5 1.4 0 / 0 NO Monitored Full 10700001 6 Cadmium 13 / 3 0.09 0.04 0.02 0 / 0 NO Monitored Full 10700001 6 Chromium 13 / 3 1.1 0.8 0.8 0 / 0 NO Monitored Full 10700001 6 Lead 13 / 3 0.48 0.16 0.13 0 / 0 NO Monitored Full 10700001 6 Nickel 13 / 3 3.2 2.4 2.4 0 / 0 NO Monitored Full 10700001 6 Silver 13 / 3 0.025 0.025 0.025 0 / 0 NO Monitored Full 10700001 6 Zinc 13 / 3 3 2.05 2.3 0 / 0 NO Monitored Full Class
BWW1 - Biological Sampling: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 72d BMIBI BIT BMIBI Pass/Fail 849 8/27/18 7789 72d MS Floating Art Sub 35 Fair 51 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/1) Not Assessment was evaluated
because the drainage area of the sample site Overall Evaluated Fail WINOFI 3bu was greater than the
calibrated range.
Benthic Macroinvertebrates:
Overall:
Class HH – No Data
Assessment Key Dates
8/27/2018 | Biological Monitoring |
1/2/2018 | Fixed Monitoring Start Date |
12/9/2020 | Fixed Monitoring End Date |
Methods
230 | Fixed station physical/chemical (conventional plus toxic pollutants) |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |