Trumbull Lake IA 06-LSR-1636
Clay County S27T97NR35W 5 mi NE of Dickens.
- Cycle
- 2022
- Release Status
- Final
- Overall IR
- 4 - Water is impaired or threatened and a TMDL has been completed or is not needed.
- Trophic
- Hypereutrophic
- Trend
- Stable
- Created
- 1/4/2022 9:18:00 AM
- Updated
- 2/2/2022 2:52:56 PM
The Class A1 use was assessed (monitored) as “not supported” due to pH and very poor water transparency related to high levels of inorganic turbidity that violated Iowa’s narrative water quality standard protecting against aesthetically objectionable conditions. High levels of algae at this lake also suggested an impairment by contributing to aesthetically objectionable conditions and nuisance aquatic life. The Class BLW use was assessed (monitored) as “not supported” due to the Class BLW criteria for pH. Additionally, the Class BLW use was assessed (evaluated) as “WINOFI” due to nuisance blooms of algae and re-suspension of sediment. All other designated uses were “not assessed.” Note: A TMDL for algae and turbidity at Trumbull Lake was prepared by DNR and approved by EPA in 2006. Because all Section 303(d) impairments identified for the current assessment/listing cycle (algal growth, turbidity, and pH) are addressed by the TMDL, this waterbody is placed in IR Category 4a (impaired; TMDL approved.)
Data Sources: Data Source Data Source ID Data Type Data Age Site ID Site
Name Site
Description Iowa DNR 6 WQ CY 2016-2020 22210001 Trumbull
Lake Max Depth
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 22210001 6 28 / 5 7.2 10.9 8.6 6 6 YES Monitored Not 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 22210001 6 Chlorophyll a TSI 28 / 5 24 84 60 NO Monitored Full 22210001 6 Secchi TSI 24 / 5 55 80 70 YES Monitored Not 22210001 6 Total Phosphorus TSI 28 / 5 44 89 72 NA NA NA 22210001 6 Inorganic suspended solids 18 / 3 0.06 15 3.55 NA NA NA Although the index value for Chlorophyll a was below the
impairment trigger of 65 for this assessment cycle, the Class A1 use of Trumbull 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 5). Therefore,
Trumbull 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 22210001 6 Ammonia 23 / 4 0.0003 0.19 0.04 NA 0 / 0 5 NO Monitored Full 22210001 6 Dissolved Oxygen 28 / 5 4.37 16.05 9.4 1 NA / NA 6 NO Monitored Full 22210001 6 pH 28 / 5 7.2 10.9 8.6 6 NA / NA 6 YES Monitored Not 22210001 6 Temperature 28 / 5 11.84 28 21.46 0 NA / NA 6 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 22210001 6 3 81.84 87.9% 19.57 84.4% YES Evaluated 3b
Class HH: No Data