Lake Meyer IA 01-TRK-158
Winneshiek County S34T97NR9W 3 mi SW of Calmar.
- Cycle
- 2024
- 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
- Secchi TSI's continue to decline in this waterbody.
- Created
- 11/1/2023 8:12:41 AM
- Updated
- 2/2/2024 3:16:02 PM
The Class A1 use was assessed as “fully supported.” The Class BLW use was assessed as “fully supported.” The Class HH (fish consumption) use was assessed (evaluated) as "WINOFI" based on fish tissue sampling data. According to DNR’s assessment methodology, the one-time occurrence of a level of mercury above an advisory threshold level does not suggest impairment of the Class HH use. The Iowa DNR/DPH advisory protocol states that two consecutive samplings that show contaminant levels are above the threshold level in edible tissue are needed to justify issuance of an advisory. Additional monitoring will be conducted to better determine levels of mercury in the edible portions (fillets) of fish in this lake. Note: A TMDL for nutrients and siltation at Lake Meyer was prepared by DNR and approved by EPA in 2005.
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2018-2022 22960004 Lake
Meyer (maximum water depth)
Iowa DNR 6 FT See
Below 1078 Lake Meyer W of Calmar Class A1 - 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 22960004 6 12 / 4 7.5 9 8.1 0 4 NO Mon 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 22960004 6 Chlorophyll a TSI 12 / 4 26 76 59 NO Mon Full 22960004 6 Secchi TSI 12 / 4 35 73 48 NO Mon Full 22960004 6 Total Phosphorus TSI 12 / 4 37 79 61 NA NA NA 22960004 6 Fixed suspended solids 12 / 4 0.6 10 1.9 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 22960004 6 Dissolved Oxygen 12 / 4 4.45 17 8.83 2 NA / NA 4 NO Mon Full 22960004 6 pH 12 / 4 7.5 9 8.1 0 NA / NA 4 NO Mon Full 22960004 6 Temperature 12 / 4 14.4 25.9 22 0 NA / NA 4 NO Mon 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 22960004 6 2 0.037312512 56% 0.018656256 28% 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 22960004 6 Ammonia 12 / 4 0.187 0.08 0.06 0 / 0 NO Mon Full 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) 1078 tissue plug 2020 bluegill 10 21.2 0.261
1078 tissue plug 2019 largemouth bass 10 35.4 0.319
1078 tissue plug 2017 largemouth bass 3 35.7 0.193
Support Level WINOFI The Class HH (fish consumption) use was potentially
impaired due to single sample above an advisory threshold. Further monitoring
is needed to confirm impairment.