Manteno Park Pond IA 06-BOY-1505
Shelby County S2T81NR40W 8 mi NW of Defiance.
- 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
- Eutrophic
- Trend
- Stable
- Created
- 10/27/2025 3:10:17 PM
- Updated
- 11/21/2025 3:07:31 PM
| Cycle Added | Class | Cause | Data Source | Rationale |
|---|---|---|---|---|
| 2022 | Class BLW | Organic Enrichment: Low Dissolved Oxygen | Ambient monitoring: Iowa DNR-lakes | New data: WQ improvement (chemical / physical / bacterial) |
The Class A1 use was assessed (monitored) as “fully supported.” The Class BLW 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 2020-2024 22830001 Manteno
Lake
Class A - Indicator Bacteria: No Data 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 22830001 6 13 / 5 7.34 8.96 8.11 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 22830001 6 Chlorophyll a TSI 13 / 5 52 75 64 NO MONITORED FULL 22830001 6 Secchi TSI 13 / 5 49 72 62 NO MONITORED FULL 22830001 6 Total Phosphorus TSI 13 / 5 61 102 74 NA NA NA 22830001 6 Fixed suspended solids 13 / 5 1.7 55.5 3 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 22830001 6 Dissolved Oxygen 12 / 5 3.7 10 6.6 2 NA / NA 4 NO MONITORED FULL 22830001 6 pH 13 / 5 7.34 8.96 8.11 0 NA / NA 4 NO MONITORED FULL 22830001 6 Temperature 13 / 5 17.2917 28 22.853 0 NA / NA 4 NO MONITORED FULL Manteno Lake was assessed as "not supported" for the
2022 assessment/listing cycle based on Dissolved Oxygen. Based on DNR’s
assessment methodology the current assessment/listing cycles must have fewer
violations of the criterion based on the minimum required by the 10% Rule to
propose delisting. There were less than 10% of the samples exceeding the
single-sample maximum criterion for the current assessment listing cycle.
Therefore, the impairment for Dissolved Oxygen is suggested for delisting for
the 2026 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 22830001 6 4 421.447408 81.05% 0.067372275 0.55% 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 22830001 6 Ammonia 13 / 5 0.187 0.04 0.02 0 / 0 NO MONITORED FULL
Class HH - No Data