Assessment Comments
Assessment is based on: (1) results of the statewide survey of Iowa lakes conducted from 2004 through 2007 by Iowa State University (ISU), (2) results of the statewide ambient lake monitoring program conducted from 2005 through 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” 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 2004 through 2007 by Iowa State University (ISU), (2) results of the statewide ambient lake monitoring program conducted from 2005 through 2008 by University Hygienic Laboratory (UHL), and (3) information from the IDNR Fisheries Bureau.
EXPLANATION: For the 2010 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 2004 through 2008 (approximately 21 samples), Carlson’s (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 62, 61, and 65 respectively for Badger Lake. According to Carlson (1977) the chlorophyll a, Secchi depth, and total phosphorus values place Badger Lake in between the eutrophic and hypereutrophic categories. These values suggest moderately high 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 also 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 4.2 mg/L, which was the 61st highest of the 132 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 (2.7 mg/L) was the 15th lowest of all 132 monitored lakes.
The Class B(LW) (aquatic life) uses are assessed (evaluated) as “partially supported” based on information from the IDNR Fisheries Bureau, and results from the ISU and UHL lake surveys. 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 2004-2008 there were no violations of the Class B(LW) criterion for ammonia (20 samples), dissolved oxygen (20 samples), or pH (20 samples).
Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring in this lake.
