Nodaway River IA 05-NOD-1388

Assessment Comments

Assessment remains based on results of U.S. EPA/IDNR fish tissue monitoring in 2007.

Basis for Assessment

[Note:  Prior to the 2008 Section 305(b) cycle, this stream segment was designated only for Class B(WW) aquatic life uses, including fish consumption uses.   Due to changes in Iowa’s surface water classification that were approved by U.S.  EPA in February 2008 (see http://www.iowadnr.com/water/standards/files/06mar_swc.pdf), this segment is also now presumptively designated for Class A1 (primary contact recreation) uses.   This segment remains designated for warmwater aquatic life use (now termed Class B(WW1) uses), and for fish consumption uses (now termed Class HH (human health/fish consumption uses).]

SUMMARY:  The presumptive Class A1 (primary contact recreation) uses and the Class B(WW1) (aquatic life) uses remain "not assessed" due to a lack of information upon which to base an assessment.   The fish consumption uses remain assessed (monitored) as "fully supported" based on U.S.  EPA/IDNR fish tissue monitoring in 2007.  

EXPLANATION: Fish consumption uses remain assessed (monitored) as “fully supported” based on results of U.S.  EPA/IDNR fish contaminant (RAFT) monitoring at the Nodaway River south of Shambaugh in 2007.   The composite samples of fillets from channel catfish had low levels of contaminants.   Levels of primary contaminants in the composite sample of channel catfish fillets were as follows: mercury: 0.087 ppm; total PCBs: <0.09 ppm; and technical chlordane: 0.068 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 river segment 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.