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
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:51 AM
- Updated
- 1/17/2024 7:29:38 AM
Assessment Summary
The 2020-2022 E. coli data suggest full support of the Class A1 use; however, delisting an impairment requires a monitored assessment. Therefore, the Category 5a Class A1 impairment will remain. 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 and the existence of a historic mercury consumption advisory in this segment.
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2020-2022 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 1061 Cedar River At Midway Site ID Data Source ID # Samples per Year (2020/ 2021/2022) 2020 Geometric Mean 2021 Geometric Mean 2022 Geometric Mean Violates Annual Geometric Mean? # 2020 SSM violations / SSM Violations needed for impairment # 2021 SSM violations / SSM Violations needed for impairment # 2022 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 10340001 6 8/8/8 39 67 74 NO 0 / 3 2 / 3 1 / 3 NO Mon Full The 2020-2022 E. coli data suggest full support of the Class A1 use; however, delisting an impairment requires a monitored assessment. Therefore, the Category 5a Class A1 impairment will remain. 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 7.7 8.6 8.2 0 7 NO Mon Full 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 Chloride 36 / 3 13 42 27 NA 0 / 0 7 NO Mon Full 10340001 6 Dissolved Oxygen 36 / 3 5.5 15.1 10.8 0 NA / NA 7 NO Mon Full 10340001 6 pH 36 / 3 7.7 8.6 8.2 0 NA / NA 7 NO Mon Full 10340001 6 Sulfate 36 / 3 10 35 25 0 NA / NA 7 NO Mon Full 10340001 6 Temperature 36 / 3 0.1 26.4 11.5 0 NA / NA 7 NO Mon Full 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 Ammonia 36 / 3 0.64 0.1 0.02 0 / 0 NO Mon Full 10340001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10340001 6 Chromium 20 / 3 1.1 0.6 0.5 0 / 0 NO Mon Full 10340001 6 Lead 20 / 3 1 0.91 1 0 / 0 NO Mon Full 10340001 6 Nickel 20 / 3 2.7 1.3 1.1 0 / 0 NO Mon Full 10340001 6 Selenium 18 / 2 2 1.2 1 0 / 0 NO Mon Full 10340001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10340001 6 Zinc 20 / 3 2.8 1.1 1 0 / 0 NO Mon 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 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 Overall Evaluated Pass Full 1 the sample site was greater than the
calibrated range. Site ID Data Source ID # Days Monitoring (2016) DO Criteria Type # 2016 violations / Violations needed for impairment Violates Annual Significantly >10% Rule? Assessment Type Support Level 24 hr 0/5 No 285 6 24 16 hr 0/5 No Evaluated Full Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 1061 tissue plug 2014 smallmouth bass 4 35.1 0.27 1061 tissue plug 2012 smallmouth bass 5 37.9 0.464 Support Level Not A historic 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.” 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 10340001 6 Selenium 18 / 2 2 1.2 1 3 NO Mon Full
Class A1 - Indicator Bacteria:
Class A1 – pH:
Class BWW1 - Binomial Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Overall:
Class BWW1 - Continuous DO Monitoring:
Class HH - Fish Tissue Sampling:
Class HH-F - Toxic Parameters:
Assessment Key Dates
9/22/2014 | Fish Tissue Monitoring |
8/15/2016 | Biological Monitoring |
8/9/2020 | Biological Monitoring |
9/12/2012 | Fish Tissue Monitoring |
1/9/2020 | Monitoring Start |
12/8/2022 | Monitoring End |
Methods
150 | Monitoring data more than 5 years old |
200 | Physical/Chemical Monitoring |
260 | Fish tissue analysis |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |