Assessment Comments
Assesment is based on results of U.S. EPA/IDNR fish tissue (RAFT) monitoring.
Basis for Assessment
SUMMARY: The general aquatic life uses were not assessed. Fish consumption uses remain assessed as "not supporting." Other beneficial uses of this "general use" lake were not assessed.
EXPLANATION: Because data are not available to develop an assessment of support of the general aquatic life uses, these uses are considered "not assessed." Results of EPA/DNR fish tissue (RAFT) monitoring in 2002 showed that levels of technical chlordane in the samples from Cedar Lake were high relative to samples from other RAFT sites in Iowa. Levels of primary contaminants in the composite sample of common carp fillets were as follows: mercury: 0.028 ppm; total PCBs: 0.440 ppm; and technical chlordane: 0.20 ppm. Although elevated relative to other RAFT sites, the contaminant levels in the sample of common carp fillets from Cedar Lake do not suggest the need to issue a consumption advisory. Levels of primary contaminants in the composite sample of channel catfish fillets, however, were higher, and the level of technical chlordane does justify the continuance of the existing consumption advisory at this lake: mercury: <0.0181 ppm; total PCBs: 1.22 ppm; and technical chlordane: 0.77 ppm. The level of chlordane in the sample of channel catfish fillets (0.77 ppm) is more than twice the FDA action level of 0.3 ppm. Thus, the fish consumption advisory issued for this lake in 1986 will continue, and fish consumption uses will remain assessed as "not supported.". This lake will be again monitored as part of the EPA/DNR fish tissue monitoring program in 2004.
