Badger Creek Lake IA 04-LDM-1100

For the 2016 assessment/listing cycle, the Class A1 (primary contact recreation) uses of Badger Creek Lake are assessed (monitored) as "not supported" due to poor water transparency and aesthetically objectionable conditions caused by algae blooms based on information from the ISU lake survey. Using the median values from these surveys from 2010-2014 (approximately 15 samples), Carlson 's (1977) trophic state indices for Secchi depth, chlorophyll a, and total phosphorus were 67, 71, and 74 respectively for Badger Creek Lake. According to Carlson (1977) the Secchi depth, chlorophyll a, and total phosphorus values all place Badger Creek Lake in between the Eutrophic and the Hypereutrophic categories. These values suggest very high levels of chlorophyll a and suspended algae in the water, poor water transparency, and extremely high levels of phosphorus in the water column. The data show 3 violations of the Class A1 criterion for pH in 15 samples.

The level of inorganic suspended solids was moderately high at Badger Creek Lake, and does suggest that non-algal turbidity may contribute to the impairment at this lake. The median level of inorganic suspended solids in Badger Creek Lake (4.4 mg/L) was ranked 84th among the 138 lakes by the ISU lake survey.

Data from the 2010-2014 ISU lake survey suggest a moderately large population of cyanobacteria exists at Badger Creek Lake. These data show that cyanobacteria comprised 88% of the phytoplankton wet mass at this lake. The median cyanobacteria wet mass (31.8 mg/L) was ranked 98th of the 138 lakes sampled.

The Class B(LW) (aquatic life) uses for Badger Creek Lake are assessed (evaluated) as “partially supporting” based on information from the IDNR Fisheries Bureau, and results of a fish kill investigation.   Information from the IDNR Fisheries Bureau suggests that algal blooms and water clarity remain problems at this lake that affect the both the quality of the fish population and the likelihood of anglers using the lake.   In addition, sediment resuspension, a lack of aquatic vegetation, and shoreline erosion are also problems at this lake.  

Fish kills that occurred in this lake on or before May 17, 2007 and March 21, 2011 also suggests "impairment" of the Class B(LW) uses.   The 2007 kill was identified as a natural kill related to spawning stress.   Monitoring of the lake showed that the pH was high (9.2) and there was a large amount of brown algae in the lake.   The total number of fish killed was estimated to be 1000.   This is the same assessment as that developed for the 2010, 2012 and2014 assessment/listing cycles.  The 2011 kill was identified as a natural kill and related to either oxygen depletion associated with winter kill and/or lake turnover effect.  10 fish were reported as killed.  The continuance of the IR Category 2b listing is based on IDNR's 2012 assessment methodology that states the following:  the occurrence of a single pollutant-caused fish kill, or a fish kill of unknown origin, on a waterbody or waterbody reach during the most recent assessment period (2012-2014) indicates a severe stress to the aquatic community and suggests that the aquatic life uses should be assessed as “impaired.”  If a cause of the kill was not identified during the IDNR investigation, or if the kill was attributed to non-pollutant causes (e.g., winterkill), the assessment type will be considered “evaluated” and will be placed in IR subcategories 2b or 3b and will be added to the state list of waters in need of further investigation.   Thus, this assessment segment will remain in Category 3b of Iowa’s 2016 Integrated Report.  

Results of the ISU lake survey from 2010-2014 show there were one violation of the criterion for ammonia in 15 samples(7%), one violation of the criterion for dissolved oxygen in 15 samples(7%), and 3 violations of the criterion for pH in 15 samples(20%). Based on IDNR's assessment methodology these violations are not significantly greater than 10% of the samples and therefore suggest (fully supported/monitored) of the Class B(LW) uses of Badger Creek Lake.
  
Fish consumption uses were assessed (monitored) as “fully supported” based on results of U.S.   EPA/IDNR fish contaminant (RAFT) monitoring at Badger Creek Lake in 2011.    The composite samples of fillets from largemouth bass and black bullhead had low levels of contaminants.    Levels of primary contaminants in the composite sample of largemouth bass fillets were as follows: mercury: 0.124 ppm.  Levels of primary contaminants in the composite sample of black bullhead fillets were as follows: mercury: 0.0315 ppm; total PCBs: 0.09 ppm; and technical chlordane: <0.03 ppm.    The existence of, or potential for, a fish consumption advisory is the basis for Section 305(b) assessments of the degree to which Iowa’s lakes and rivers support their fish consumption uses.     The fish contaminant data generated from the YEAR RAFT sampling conducted at this WATERBODY TYPE show that the levels of contaminants do not exceed any of the advisory trigger levels, thus indicating no justification for issuance of a consumption advisory for this waterbody.

Note:  A TMDL for siltation and nutrients at Badger Creek Lake was prepared by IDNR and approved by EPA in 2003.   Because all Section 303(d) impairments identified for the 2016 assessment/listing cycle (algal growth [inlcuding nuisance growth of cyanobacteria]) are addressed by the TMDL, this waterbody remains in IR Category 4a (TMDL approved).