Iowa Army Ammunition Plant Lake (aka Mathis Lake) IA 03-SKU-6465

Assessment Comments

Assessment is based on results of IDNR/U.S. EPA fish contaminant (RAFT) monitoring in 2010.

Basis for Assessment

SUMMARY:  The Class A (primary contact recreation) and Class B(LW) aquatic life uses are "not assessed" due to a lack of data upon which to base an assessment.   The fish consumption uses are assessed (monitored) as "fully supported" based on results of turtle tissue monitoring in 2010.

EXPLANATION: Fish consumption uses were assessed (monitored) as “fully supported” based on results of U.S.  EPA/IDNR turtle contaminant (RAFT) monitoring at Iowa Army Ammunition Plant Lake in 2010.    The composite samples of shoulder tissue of a snapping turtle had low levels of contaminants.    Levels of primary contaminants in the composite sample of snapping turtle shoulders were as follows: mercury: 0.134 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 turtle contaminant data generated from the 2010 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.