Frog Hollow (aka Volga Lake) IA 01-VOL-292
Fayette County S3T93NR8W 4 mi. NNE of Fayette.
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trophic
- Eutrophic
- Trend
- Stable
- Created
- 11/1/2023 8:12:41 AM
- Updated
- 2/2/2024 3:06:10 PM
Assessment Summary
The Class A1 use was assessed as “not supported” (IR 4a) due to algae blooms and high levels of turbidity that violated Iowa’s narrative criteria protecting against aesthetically objectionable conditions. The Class BLW use was assessed (evaluated) as “WINOFI” based on information from the DNR Fisheries Bureau and as “WINOFI” due to excessive planktonic cyanobacteria. The Class HH (fish consumption) use was assessed as "fully supported" based on fish tissue monitoring data. Note: A TMDL for impairments due to algae and non-algal turbidity at this lake was prepared and approved by EPA in July 2014. The approval of this TMDL moves the impairments due to algae and non-algal turbidity from Iowa's list of Section 303(d) waters (Category 5a of the Integrated Report) to IR Category 4a (impaired; TMDL not required).
Assessment Explanation
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2018-2022 22330001 Volga
Lake (maximum water depth)
Iowa DNR 6 FT See
Below 1269 Volga
Lake (Frog Hollow Lake) Near
Fayette
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 22330001 6 9 / 3 7.7 9.1 8.4 1 3 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 22330001 6 Chlorophyll a TSI 9 / 3 42 76 65 YES Mon Not 22330001 6 Secchi TSI 9 / 3 55 83 73 YES Mon Not 22330001 6 Total Phosphorus TSI 9 / 3 37 76 70 NA NA NA 22330001 6 Fixed suspended solids 9 / 3 0.6 25 1.7 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 22330001 6 Dissolved Oxygen 9 / 3 7.1 18.2 10.2 0 NA / NA 3 NO Mon Full 22330001 6 pH 9 / 3 7.7 9.1 8.4 1 NA / NA 3 NO Mon Full 22330001 6 Temperature 9 / 3 16.6 26.5 23.3 0 NA / NA 3 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 22330001 6 2 29.76320714 74% 20.59683328 69% YES Evaluated WINOFI 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 22330001 6 Ammonia 9 / 3 0.103 0.04 0.04 0 / 0 NO Evaluated 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) 1269 tissue plug 2019 largemouth bass 10 32 0.076
Support Level Full
Assessment Key Dates
| 7/21/2014 | TMDL Completed |
| 8/23/2022 | Monitoring End |
| 6/18/2018 | Monitoring Start |
| 7/1/2019 | Fish Tissue Monitoring |
Methods
| 120 | Surveys of fish and game biologists/other professionals |
| 200 | Physical/Chemical Monitoring |
| 260 | Fish tissue analysis |
| 340 | Primary producer surveys (phytoplankton/periphyton/macrophyton) |