Cedar River IA 02-CED-477
from upper end of Nashua Impoundment (Chickasaw/Floyd county line (W line S7 T94N R14W Chickasaw Co.)) to Dam No. 2 at Charles City in NW 1/4 NE 1/4 S12 T95N R16W Floyd 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
- 12/22/2021 6:56:48 AM
- Updated
- 3/30/2022 9:32:29 AM
Assessment Summary
The Class A1 use was assessed as "not supported" due to violations of Class A1 criteria for indicator bacteria (E. coli). The Class BWW1 use was assessed as "fully supported" based on biological sampling data and water quality monitoring data. The Class HH (fish consumption) use remains assessed as "not supported" based on fish tissue sampling data. Note: A TMDL for the bacteria impairment in the Cedar River was prepared and was approved by EPA in February 2010. However, this segment was not included in the TMDL; therefore, the bacteria impairment of the Class A1 primary contact recreation use for this segment remains in IR Category 5a (TMDL needed).
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 10340001 Cedar River near Charles City (DS1)
Iowa
DNR 6 BIO See
Below 285 Cedar River Carrville/Charles City Iowa DNR 6 FT See Below 61 Cedar River At Midway 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 10340001 6 7/8/8 153 151 39 YES 3 / 3 3 / 3 0 / 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 10340001 6 36 / 3 7.1 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 10340001 6 Ammonia 36 / 3 0.025 0.9 0.1 NA 0 / 0 7 NO Monitored Full 10340001 6 Chloride 36 / 3 8.8 36 21.5 NA 0 / 0 7 NO Monitored Full 10340001 6 Dissolved Oxygen 36 / 3 7.3 14.8 10.7 0 NA / NA 7 NO Monitored Full 10340001 6 pH 36 / 3 7.1 8.6 8.1 0 NA / NA 7 NO Monitored Full 10340001 6 Sulfate 36 / 3 8.1 32 21.2 0 NA / NA 7 NO Monitored Full 10340001 6 Temperature 36 / 3 0.1 26.4 10.7 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 10340001 6 Aluminum 14 / 3 2.2 0.4 0.1 0 / 0 NO Monitored Full 10340001 6 Arsenic 13 / 3 10 5.21 6.1 0 / 0 NO Monitored Full 10340001 6 Cadmium 13 / 3 0.08 0.03 0.02 0 / 0 NO Monitored Full 10340001 6 Chromium 13 / 3 1.2 0.9 0.9 0 / 0 NO Monitored Full 10340001 6 Lead 13 / 3 0.18 0.11 0.1 0 / 0 NO Monitored Full 10340001 6 Nickel 13 / 3 3.5 2.7 2.7 0 / 0 NO Monitored Full 10340001 6 Silver 13 / 3 0.025 0.025 0.025 0 / 0 NO Monitored Full 10340001 6 Zinc 13 / 3 3.3 1.9 1.8 0 / 0 NO Monitored Full Site
ID Date Drainage
Area (mi2) Ecoregion Major
Drainage BM
Sample Gear BMIBI
score BMIBI
Class 47c
BMIBI BIT BMIBI
Pass/ Fail 285 8/9/20 1095 47c MS Floating
Art Sub 76 Excellent 52 Pass 285 8/15/16 1095 47c MS Hess 86 Excellent 70 Pass Overall: Community Assessment
Type Assessment
Result Support
Level IR
Category Reason Benthic Macroinvertebrates Evaluated Pass
(2/2) Full Assessment was evaluated because the drainage area of the
sample site Overall Evaluated Pass Full 1 was greater than the calibrated range. Class BWW1 - Continuous DO Monitoring:
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 0/5 NA NA NA NA No
285 6 24/0/0/0/0 16 hr 0/5 NA NA NA NA No Evaluated Full Class HH - Fish
Tissue Sampling: Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 61 fillet 2012 channel catfish 5 40.6 0.172 0.03 0.09 61 tissue plug 2014 smallmouth bass 4 35.1 0.27
61 tissue plug 2012 smallmouth bass 5 37.9 0.464
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.”
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Assessment Key Dates
| 9/22/2014 | Fish Tissue Monitoring |
| 8/15/2016 | Biological Monitoring |
| 1/8/2018 | Fixed Monitoring Start Date |
| 12/7/2020 | Fixed Monitoring End Date |
| 8/9/2020 | Biological Monitoring |
| 9/12/2012 | Fish Tissue Monitoring |
Methods
| 150 | Monitoring data more than 5 years old |
| 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 |