Lacey Keosauqua Lake IA 04-LDM-1008
Van Buren County S2T68NR10W 1 mi S of Keosauqua
- Cycle
- 2026
- Current Phase
- Public Comment
- Overall IR
- 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
- Trophic
- Mesotrophic
- Trend
- Stable
- Created
- 10/27/2025 3:09:47 PM
- Updated
- 11/24/2025 2:25:53 PM
The Class A1 use was assessed (monitored) as “fully supported.” The Class BLW use was assessed (monitored) as “fully supported.” The Class C use was assessed (monitored) as “fully supported.” All other designated uses were “not assessed.”
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2022-2024 21890001 Lacey-Keosauqua
Beach
Iowa DNR 6 WQ CY 2021-2024 22890004 Lacey
Keosauqua Lake
Class A1 - Indicator Bacteria: Site ID Data Source ID # Samples per Year (2022/ 2023/2024) 2022 Geometric Mean 2023 Geometric Mean 2024 Geometric Mean Violates Annual Geometric Mean? # 2022 SSM violations / SSM Violations needed for impairment # 2023 SSM violations / SSM Violations needed for impairment # 2024 SSM violations / SSM Violations needed for impairment Violates Annual SSM Significantly >10% Rule? Assessment Type Support Level 21890001 6 15/14/15 11 7 14 NO 0 / 4 0 / 4 1 / 4 NO MONITORED FULL Class A1 - 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 22890004 6 12 / 4 7.57 8.27 7.96 0 4 NO MONITORED FULL Class A1 - Lake TSI's Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value Maximum Value Median Value Median TSI Violation? Assessment Type Support Level 22890004 6 Chlorophyll a TSI 12 / 4 39 63 46 NO MONITORED FULL 22890004 6 Secchi TSI 12 / 4 45 87 50 NO MONITORED FULL 22890004 6 Total Phosphorus TSI 12 / 4 37 81 48 NA NA NA 22890004 6 Fixed suspended solids 12 / 4 1.7 28 2 NA NA NA Class BLW - Binomial 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 22890004 6 Dissolved Oxygen 12 / 4 4.9 8.4 7 1 NA / NA 4 NO MONITORED FULL 22890004 6 pH 12 / 4 7.57 8.27 7.96 0 NA / NA 4 NO MONITORED FULL 22890004 6 Temperature 12 / 4 18.8222 29 24.975 0 NA / NA 4 NO MONITORED FULL 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 22890004 6 2 4.641 39.43% 2.3564 25.95% NO EVALUATED NA Class BLW - 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 22890004 6 Ammonia 12 / 4 0.092 0.03 0.02 0 / 0 NO MONITORED FULL Class C - Binomial Parameters: 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 22890004 6 Inorganic nitrogen (nitrate and nitrite) 11 / 4 0.05 0.78 0.19 0.07 0 NO MONITORED FULL 22890004 6 pH 12 / 4 7.57 8.27 7.96 7.97 0 NO MONITORED FULL Class HH - No Data