Iowa River IA 02-IOW-628
from Burlington St. dam in Iowa City (Johnson Co.) to Coralville Reservoir dam (Johnson Co.)
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
- Trend
- Unknown
- Created
- 11/1/2023 8:12:47 AM
- Updated
- 2/12/2024 7:40:56 AM
The Class A1 use was assessed as "fully supported" based on water quality monitoring data. The Class BWW1 use was assessed as "WINOFI" based on biological sampling data. The Class C (drinking water) use was assessed as "fully supported" based on water quality monitoring data and drinking water compliance monitoring required by the DNR. The Class HH (fish consumption) use remains assessed as "fully supported" based on fish tissue sampling data. Note: A TMDL for indicator bacteria in this segment of Iowa River approved by EPA in June 2007. The approval of this TMDL moves the bacterial impairment for this segment from Iowa's list of Section 303(d) waters (Category 5a) to Category 4a (impaired; TMDL not required). Additionally, a TMDL covering the bacteria impairments for all segments, with the segment code prefix "IA 02-IOW" in the Iowa River Basin, was approved by EPA in 2018.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description USACE 12 WQ CY 2020-2022 2222222 Iowa River
(Downstream Coralville Reservoir) PWS 27 WQ CY 2020-2022 99990175 Iowa River PWS 27 WQ CY 2020-2022 99990176 Iowa River Iowa DNR 6 BIO See Below 941 Iowa River Iowa City - US1 Iowa DNR 6 FT See Below 1125 Iowa River at Iowa
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 2222222 12 10/9/9 26 15 29 NO 1 / 3 0 / 3 2 / 3 NO Mon Full 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 2222222 12 60 / 3 7.3 8.6 8.1 0 10 NO Mon Full 99990175 27 5699 / 3 7 9.32 8.3 12 600 NO Mon Full 99990176 27 73 / 3 7.41 8.84 8.21 0 12 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 2222222 12 Dissolved Oxygen 60 / 3 5.95 15.41 10.2 0 NA / NA 10 NO Mon Full 2222222 12 pH 60 / 3 7.3 8.6 8.1 0 NA / NA 10 NO Mon Full 99990175 27 pH 5699 / 3 7 9.32 8.3 12 NA / NA 600 NO Mon Full 99990176 27 pH 73 / 3 7.41 8.84 8.21 0 NA / NA 12 NO Mon Full 2222222 12 Temperature 60 / 3 0.1 27.9 15.3 0 NA / NA 10 NO Mon Full 99990175 27 Temperature 5732 / 3 0.55556 30.1667 14.156 0 NA / NA 603 NO Mon Full 99990176 27 Temperature 77 / 3 -4 29 13 0 NA / NA 12 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 2222222 12 Ammonia 59 / 3 0.664 0.18 0.15 0 / 0 NO Mon Full Site ID Date Drainage Area (mi2) Ecoregion Major Drainage BM Sample Gear BMIBI score BMIBI Class 47f BMIBI BIT BMIBI Pass/Fail 941 10/10/14 3158 47f MS Floating Art Sub 38 Fair 51 Fail 941 9/19/13 3158 47f MS Art Sub 20 Poor 51 Fail Community Assessment Type Assessment Result Support Level IR Category Reason Benthic
Macroinvertebrates Evaluated Fail (0/2) WINOFI Assessment was evaluated because the
drainage area of Overall Evaluated Fail WINOFI 3bu the sample site was greater than the
calibrated range. Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Mean Value Median Value # Violations Violates Significantly >10% Rule? Assessment Type Support Level 2222222 12 Inorganic nitrogen (nitrate and nitrite) 59 / 3 0.1 11.9 3.4 3 3 NO Mon Full 99990175 27 Nitrate 2698 / 3 0.05 13.8 3.2 3.3 18 NO Mon Full 99990176 27 Nitrate 146 / 3 0.13 12 3.39 3.12 5 NO Mon Full 2222222 12 pH 60 / 3 7.3 8.6 8.1 8.1 0 NO Mon Full 99990175 27 pH 5699 / 3 7 9.32 8.3 8.3 12 NO Mon Full 99990176 27 pH 73 / 3 7.41 8.84 8.21 8.21 0 NO Mon Full Site ID Data Source ID Parameter Name # Samples per Year (2020/ 2021/2022) 2020 Mean 2021 Mean 2022 Mean # Non-Detects per Year (2020/ 2021/2022) Support Level per Year (2020/ 2021/2022) Assessment Type Support Level 99990176 27 Alachlor 9/9/12 0 0 0 9/9/12 Full/Full/Full Mon Full 99990176 27 Atrazine 4/8/18 0 0 0.633 4/8/15 Full/Full/Full Mon Full 99990176 27 Simazine 9/9/12 0 0 0 9/9/12 Full/Full/Full Mon Full Class C - Iowa Drinking Water Compliance Report: Compliance monitoring required by the Iowa DNR Water Supply Operations and Engineering Sections did not show violations of finished water caused by source water at the Iowa City Water Department and University Water System facilities during the 2020-22 monitoring period. The results of compliance monitoring as reported in annual compliance reports are available at the following location at the Iowa DNR’s home page: https://www.iowadnr.gov/Environmental-Protection/Water-Quality/Water-Supply-Engineering/Annual-Compliance-Report. 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) 1125 fillet 2015 common carp 5 48.8 0.09 0.02 0.06 1125 tissue plug 2015 white bass 5 35.6 0.05 Support Level Full
Class A1 - Indicator Bacteria:
Class A1 – pH:
Class BWW1 - Binomial Parameters:
Class BWW1 - Toxic Parameters:
Class BWW1 - Biological Sampling:
Benthic Macroinvertebrates:
Overall:
Class C - Binomial Parameters:
Class C - Toxic Parameters: