Trumbull Lake IA 06-LSR-1636
Clay County S27T97NR35W 5 mi NE of Dickens.
- Cycle
- 2020
- 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
- 8/27/2020 1:53:53 PM
- Updated
- 10/15/2020 8:13:25 AM
The Class A1 uses are assessed (monitored) as “not supported” due to pH, very poor water transparency related to high levels of inorganic turbidity that violate Iowa’s narrative water quality standard protecting against aesthetically objectionable conditions. High levels of algae at this lake also suggest an impairment by contributing to aesthetically objectionable conditions and nuisance aquatic life. The Class BLW uses remain assessed (monitored) as “partially supported” due to pH, excessive nutrient loading to the water column, nuisance blooms of algae, and re-suspension of sediment. All other designated uses are “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.)
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 22210001 Trumbull Lake Max Depth
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 22210001 6 23 / 4 10.88 8.83 8.8 6 26% 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 79 64 NO Monitored Full 22210001 6 Secchi TSI 23 / 4 56 80 67 YES Monitored Not 22210001 6 Total Phosphorus TSI 28 / 5 44 90 72 NA NA NA 22210001 6 Inorganic suspended solids 28 / 5 0.06 17.5 4.63 NA NA NA Although the index value for Chlorophyll a is below the impairment trigger of 65 for this assessment cycle, Trumbull Lake was listed as partially supporting its Class A1 uses 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 2020 assessment/listing cycle. 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 22210001 6 Ammonia 23 / 4 0.1234 0.03 0.02 0 / 0 0% / 0% NO Monitored Full 22210001 6 Dissolved oxygen 23 / 4 18.6 10.15 9.28 NA / 0 NA / 0% NO Monitored Full 22210001 6 pH 23 / 4 10.88 8.83 8.8 6 / NA 26% / NA YES Monitored Not 22210001 6 Temperature 23 / 4 29.3 22.2 23.2 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 22210001 6 8 103.468 94.2 % 49.673 79.65 % YES Evaluated 3b Class HH - No Data Additional Note: The lake was drawn down in 2012 and rough fish were removed throughout the wetland complex and water control structures were installed to help regulate water levels in the wetland complex and at Trumbull Lake. The lake was refilled in 2014. Dramatic water quality improvements were noted.