South Prairie Lake IA 02-CED-962
Black Hawk Co.; west of Waterloo in S35 T89N R14W
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
- Trophic
- Eutrophic
- Trend
- Improving
- Trend Comment
- The lakes pH level contine to improve leading the delisting of the pH impairment in the 2022 assessment cycle.
- Created
- 12/27/2021 10:37:41 AM
- Updated
- 2/1/2022 9:13:05 AM
| Cycle Added | Class | Cause | Data Source | Rationale |
|---|---|---|---|---|
| 2018 | Class BLW | pH | Ambient monitoring: Iowa DNR-lakes | New data: WQ improvement (chemical / physical / bacterial) |
The Class BLW use was assessed as "fully supported." All other designated uses were “not assessed.” Note: This lake is not designated for Class A1 (primary contact recreation) use.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2016-2020 22070005 South
Prairie Lake
Class BLW - 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 22070005 6 Ammonia 15 / 5 0.0003 0.2904 0.05 NA 0 / 0 4 NO Monitored Full 22070005 6 Dissolved Oxygen 15 / 5 4 14.8 9.8 1 NA / NA 4 NO Monitored Full 22070005 6 pH 15 / 5 7.8 9.2 8.6 1 NA / NA 4 NO Monitored Full 22070005 6 Temperature 15 / 5 17.2 28 24 0 NA / NA 4 NO Monitored Full South Prairie Lake was assessed as "not supported"
for the 2018 assessment/listing cycle due to frequent violations of the state
Class BLW criterion for pH. Based on DNR’s assessment methodology 2
consecutive assessment/listing cycles without significantly greater than 10% of
the samples violating the single-sample maximum criterion are necessary to
propose delisting based on pH violations. There were less than 10% of the
samples exceeding the single-sample maximum criterion for the 2020or
current 2022assessment listing cycle. Therefore, the impairment for pH is
suggested for delisting for the 2022 assessment/listing cycle. Class BLW - Lake Planktonic Cyanobacteria: Site ID Data Source ID # Samples Maximum Cyanobacteria Wet Mass Maximum Cyanobacteria % Composition Median Cyanobacteria Wet Mass Median Cyanobacteria % Composition Median Cyanobacteria Concentration = 75th Percentile Assessment Type Support Level 22070005 6 6 34.20 73.1% 1.88 45.1% NO Evaluated NA
Class HH: No Data