Lower Brown Lake IA 01-NEM-6315

Assessment Comments

Assessment is based on results of U.S. EPA/IDNR fish contaminant (monitoring) in 2007.

Basis for Assessment

SUMMARY: The Class A1 (primary contact recreation) and Class B(WW-1) (aquatic life) uses are "not assessed" due to lack of information upon which to base an assessment.   The fish consumption uses are assessed (monitored) as "fully supported" based on results of fish contaminant monitoring in 2007.

EXPLANATION: Fish consumption uses were assessed (monitored) as “fully supported” based on results of U.S.  EPA/IDNR fish contaminant (RAFT) monitoring at Lower Brown Lake in 2007.    The composite samples of fillets from common carp and black crappie had low levels of contaminants.    Levels of primary contaminants in the composite sample of common carp fillets were as follows: mercury: 0.1 ppm; total PCBs: 0.09 ppm; and technical chlordane: <0.03 ppm.    The level of mercury in the composite sample of black crappie fillets was 0.114 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 2007 RAFT sampling conducted at this lake 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.