North Raccoon River IA 04-RAC-1132
from confluence with Indian Cr. (S24 T87N R36W Sac Co.) to confluence with Cedar Cr. in S25 T88N R36W Sac Co.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:59 AM
- Updated
- 12/18/2023 2:10:46 PM
Assessment Summary
The Class A1 use was assessed as "not supported" due to levels of indicator bacteria (E. coli) that violated state water quality standards. The Class BWW1 use was assessed as "WINOFI" based on biological sampling data. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue sampling data and water quality monitoring data. Note: A TMDL for pathogen indicator impairments in the Raccoon River basin was approved by EPA in 2008. Because this TMDL covers the primary Section 303(d) impairment identified for the 2006 IR cycle, this segment was moved from IR Category 5a to IR Category 4a (impaired; TMDL approved) for the 2008 cycle. This waterbody remains in IR Category 4a for the current cycle.
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 10810001 North
Raccoon River near Sac City (DS1)
Iowa DNR 6 BIO See Below 222 North
Raccoon River Sac
City Iowa DNR 6 FT See Below 1082 North
Raccoon River Downstream
of Sac City 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 10810001 6 8/8/7 227 351 379 YES 4 / 3 4 / 3 5 / 3 YES Mon Not 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 10810001 6 36 / 3 7.1 9.7 8.2 1 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 10810001 6 Chloride 36 / 3 17 79 38 NA 0 / 0 7 NO Mon Full 10810001 6 Dissolved Oxygen 36 / 3 6.5 20.1 10.9 0 NA / NA 7 NO Mon Full 10810001 6 pH 36 / 3 7.1 9.7 8.2 1 NA / NA 7 NO Mon Full 10810001 6 Sulfate 36 / 3 25 180 81 0 NA / NA 7 NO Mon Full 10810001 6 Temperature 36 / 3 0 31.1 12.2 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 10810001 6 Aluminum 21 / 3 960 209 200 0 / 1 NO Mon Full 10810001 6 Ammonia 36 / 3 0.53 0.06 0.02 0 / 0 NO Mon Full 10810001 6 Cadmium 20 / 3 0.5 0.5 0.5 0 / 0 NO Mon Full 10810001 6 Chromium 20 / 3 23 1.78 0.65 1 / 1 NO Mon Full 10810001 6 Lead 20 / 3 1 0.91 1 0 / 0 NO Mon Full 10810001 6 Nickel 20 / 3 3.1 2.1 2 0 / 0 NO Mon Full 10810001 6 Selenium 18 / 2 4 2.2 2.5 0 / 0 NO Mon Full 10810001 6 Silver 20 / 3 1 0.902 1 0 / 0 NO Mon Full 10810001 6 Zinc 20 / 3 3.6 1.2 1 0 / 0 NO Mon Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47b BMIBI BIT BMIBI Pass/Fail 222 8/29/22 709.2 47b MS Floating Art Sub 56 Good 62 Fail 222 8/20/19 709.2 47b MS Floating Art Sub 56 Good 62 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/2) WINOFI Assessment was evaluated because the
drainage Overall Evaluated Fail WINOFI 3bu area of the site is greater than the
calibrated range. Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 1082 tissue plug 2016 walleye 3 53.6 0.25 Support Level Full 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 10810001 6 Selenium 18 / 2 4 2.2 2.5 6 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 HH - Fish Tissue Sampling:
Class HH-F - Toxic Parameters:
Assessment Key Dates
1/8/2020 | Monitoring Start |
12/14/2022 | Monitoring End |
8/29/2022 | Biological Monitoring |
8/25/2016 | Fish Tissue Monitoring |
8/20/2019 | Biological Monitoring |
6/24/2008 | TMDL Completed |
Methods
200 | Physical/Chemical Monitoring |
260 | Fish tissue analysis |
315 | Regional reference site approach |
320 | Benthic macroinvertebrate surveys |
420 | Indicator bacteria monitoring |