Frog Hollow (aka Volga Lake) IA 01-VOL-292
Fayette County S3T93NR8W 4 mi. NNE of Fayette.
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trophic
- Eutrophic
- Trend
- Stable
- Created
- 12/17/2021 9:55:20 AM
- Updated
- 2/17/2022 8:40:00 AM
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. 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).
Data
Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2016-2019 22330001 Volga
Lake (maximum water depth) Iowa DNR 6 FT See Below 271 Volga
Lake (Frog Hollow Lake) Near
Fayette 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 12 / 4 7.7 9 8.3 0 4 NO Monitored Full 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 12 / 4 42 76 64 NO Monitored Full 22330001 6 Secchi TSI 12 / 4 55 83 76 YES Monitored Not 22330001 6 Total Phosphorus TSI 12 / 4 37 76 70 NA NA NA 22330001 6 Fixed suspended solids 12 / 4 0.3 31.1 3.4 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 Frog Hollow/Volga Lake was listed as "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, Volga will remain listed as
"not supported" for the 2022 assessment/listing cycle. 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 Ammonia 12 / 4 0.003 0.349 0.1 NA 0 / 0 4 NO Monitored Full 22330001 6 Dissolved Oxygen 12 / 4 5.5 13.1 8.9 0 NA / NA 4 NO Monitored Full 22330001 6 pH 12 / 4 7.7 9 8.3 0 NA / NA 4 NO Monitored Full 22330001 6 Temperature 12 / 4 18.9 26.5 23 0 NA / NA 4 NO Monitored Full 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 6 29.76 91.9% 11.12 67.9% NO Evaluated NA Site ID Biopart Year Species # in sample / # of samples Avg Length (cm) (Avg) Hg (ppm) Chlordane (ppm) Sum PCBs (ppm) 271 tissue plug 2019 largemouth bass 10 32 0.076
Support Level Full
Class A1 - Indicator Bacteria: No Data
Class A1 – pH:
Class A1 - Lake TSI's
Class BLW - Conventional Parameters:
Class BLW - Lake Planktonic Cyanobacteria:
Class HH - Fish Tissue Sampling: