Hannen Lake IA 02-IOW-704
Benton County S34T82NR11W 4 mi SW of Blairstown.
- Cycle
- 2020
- 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
- 7/24/2020 2:16:00 PM
- Updated
- 10/14/2020 9:47:27 AM
The Class A1 use is assessed (monitored) as “not supported” due to aesthetically objectionable conditions caused by algae. The Class BLW use is assessed (monitored) as “fully supported.” All other designated uses are “not assessed”. NOTE: A TMDL was prepared for and approved by the U.S. EPA in 2013 for pH and algae. Because all of the impairments at this lake are addressed by the TMDL, Hannen Lake will be categorized as category 4a; water impaired but no TMDL needed for the current assessment/listing cycle.
Sources of
Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2014-2018 22060001 Hannen Lake
Class A1 -
Indicator Bacteria: No Data Class A1 - pH: Site ID Data Source ID # Samples / # Years Maximum Value Mean Value Median Value # Violations % Violations Significantly >10% Violations Assessment Type Support Level 22060001 6 15 / 5 9 8.4 8.3 0 0% 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 22060001 6 Chlorophyll a TSI 15 / 5 36 77 66 YES Monitored Not 22060001 6 Secchi TSI 15 / 5 41 73 63 NO Monitored Full 22060001 6 Total Phosphorus TSI 15 / 5 33 85 79 NA NA NA 22060001 6 Inorganic suspended solids 15 / 5 0.3 8 1.8 NA NA NA Class BLW -
Conventional Parameters: Site ID Data Source ID Parameter Name # Samples / # Years Maximum Value Mean Value Median Value # Acute / Chronic Violations % Acute/ Chronic Violations Significantly >10% Violations Assessment Type Support Level 22060001 6 Ammonia 15 / 5 0.609 0.13 0.04 0 / 1 0% / 7% NO Monitored Full 22060001 6 Dissolved oxygen 15 / 5 11.6 7.1 7.1 NA / 3 NA / 20% NO Monitored Full 22060001 6 pH 15 / 5 9 8.4 8.3 0 / NA 0% / NA NO Monitored Full 22060001 6 Temperature 15 / 5 27.6 23.24 23.4 0 / 0 0% / 0% 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 Wet Mass = 75th
Percentile Assessment Type Support Level 22060001 6 11 77.748 99.5 % 6.981 77.9 % NO Evaluated NA Class HH - No Data