Meadow Lake IA 04-LDM-1089
Adair County S17T76NR31W 5 mi N of Greenfield.
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trophic
- Hypereutrophic
- Trend
- Stable
- Created
- 12/28/2021 10:49:24 AM
- Updated
- 3/30/2022 9:52:18 AM
The Class A1 use was assessed (monitored) as “not supported” due to aesthetically objectionable conditions caused by poor water transparency caused by algae and non-algal blooms. The Class BLW use was assessed (monitored) as "fully supported." The Class HH (fish consumption) use was assessed (monitored) as "fully supported" based on fish tissue sampling data. Note: A TMDL for Algae and Turbidity at Meadow Lake was prepared by DNR and approved by EPA in 2020. However, because the turbidity impairment didn't exist prior to TMDL development, EPA disapproved the turbidity impairment delisting. The algae impairment is addressed by the TMDL, therefore, the algae impairment of Meadow Lake was placed in IR Category 4a (TMDL approved) and the turbidity impairment remains in IR Category 5a (TMDL needed).
Data Sources: Data
Source Data
Source ID Data
Type Data
Age Site
ID Site Name Site Description Iowa
DNR 6 WQ CY
2016-2020 22010003 Meadow Lake Lake Deep Point Iowa
DNR 6 FT See
Below 269 Meadow Lake Meadow Lake Wildlife Management
Area
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 22010003 6 15 / 5 7.8 9 8.5 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 22010003 6 Chlorophyll a TSI 15 / 5 36 75 58 NO Monitored Full 22010003 6 Secchi TSI 15 / 5 51 83 72 YES Monitored Not 22010003 6 Total Phosphorus TSI 15 / 5 57 82 72 NA NA NA 22010003 6 Inorganic suspended solids 15 / 5 0.3 21 4 NA NA NA Although the index value for Chlorophyll a is below the
impairment trigger of 65 for this assessment cycle, the Class A1 use of Meadow Lake remains "not supported" due to aesthetically objectionable
conditions. Based on DNR's methodology, the median TSI value for Chlorophyll a
must be 63 or less for two consecutive assessment/listing cycles before a lake can be removed from the state's Section 303(d) list (IR Category 4a). Therefore,
Meadow Lake will remain listed as "not supported" for the 2022
assessment/listing cycle. 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 22010003 6 Ammonia 15 / 5 0.0003 0.253 0.04 NA 0 / 0 4 NO Monitored Full 22010003 6 Dissolved Oxygen 15 / 5 4.8 13.2 9 1 NA / NA 4 NO Monitored Full 22010003 6 pH 15 / 5 7.8 9 8.5 0 NA / NA 4 NO Monitored Full 22010003 6 Temperature 15 / 5 19 29.4 24.4 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 22010003 6 6 31.69 96.8% 9.12 70.0% NO Evaluated NA 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) 269 fillet 2013 channel catfish 5 41.1 0.05 <0.2 <0.6 269 tissue plug 2017 largemouth bass 3 38.4 0.23
Support Level Full