Assessment Comments
Assessment is based on: (1) results of the statewide survey of Iowa lakes conducted from 2009 through 2012 by Iowa State University (ISU), (2) results of the statewide ambient lake monitoring program conducted in 2008 by University Hygienic Laboratory (UHL), and (3) information from the IDNR Fisheries Bureau.
Basis for Assessment
SUMMARY: The Class A1 (primary contact recreation) uses are assessed (monitored) as “fully supported.” The Class B(LW) (aquatic life) uses are assessed (evaluated) as “partially supported” (IR 2b) due to siltation and water quality impacts of common carp. Fish consumption uses remain “not assessed.” Sources of data for this assessment include (1) results of the statewide survey of Iowa lakes conducted from 2009 through 2012 by Iowa State University (ISU), (2) results of the statewide ambient lake monitoring program conducted in 2008 by University Hygienic Laboratory (UHL), and (3) information from the IDNR Fisheries Bureau.
EXPLANATION: For the 2014 reporting cycle, the Class A1 (primary contact recreation) uses for Badger Lake are assessed as “fully supported” based on results from the ISU statewide survey of lakes and the UHL ambient lake monitoring program. Using the median values from these surveys from 2008 through 2012 (approximately 15 samples), Carlson’s (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 60, 59, and 65 respectively for Badger Lake. According to Carlson (1977) the Secchi depth and total phosphorus values place Badger Lake in between the eutrophic and hypereutrophic categories. The chlorophyll a score places Badger Lake in the eutrophic catergory. These values suggest relatively low levels of chlorophyll a and suspended algae in the water, moderately poor water transparency, and moderately high levels of phosphorus in the water column.
The level of inorganic suspended solids was moderately high at this lake and does not suggest impairment due to high non-algal turbidity. The median inorganic suspended solids concentration at Badger Lake was 3.0 mg/L, and ranked 57th of the 134 monitored lakes.
The presence of nuisance algal populations at this lake does not appear to be a problem. Data from the ISU and UHL lake surveys show that the median cyanobacteria wet mass at Badger Lake (9.8 mg/L) and ranked 25th of the 134 monitored lakes.
The Class B(LW) (aquatic life) uses are assessed (evaluated) as “partially supported” based on information from the IDNR Fisheries Bureau. Information from the IDNR Fisheries Bureau suggests that siltation and the impacts of common carp on turbidity at this lake impair the aquatic life uses (partial support/evaluated). The ISU and UHL lake survey results show good chemical water quality at Badger Lake. During 2008-2012 there were no violations of the Class B(LW) criterion for ammonia (15 samples), dissolved oxygen (15 samples), or pH (15 samples).
Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this lake.
