West Nishnabotna River IA 05-NSH-1444

Assessment Comments

Assessment is based on results of U.S. EPA/IDNR fish tissue (RAFT) monitoring in 2001.

Basis for Assessment

Not assessed for Section 305(b) reports prior to 2002.

SUMMARY:  The Class B(WW) aquatic life uses remain "not assessed."  The fish consumption uses are assessed as "fully supported."  This assessment is based on results of U.S.  EPA / IDNR fish tissue (RAFT) monitoring near Harlan in September 2001.   EXPLANATION:  Due to the lack of data from either chemical or biological monitoring for this river reach, the assessment of support of the Class B(WW) uses remained "not assessed."  Fish consumption uses are assessed as "fully supported" based on results of fish tissue (RAFT) monitoring near Harlan in September 2001.   Results of this monitoring show that levels of all contaminants in the composite sample of channel catfish fillets were well below the respective FDA action levels and IDNR levels of concern.   Historically, bottom-feeding fish from this river segment tended to have relatively high levels of chordane.   The levels of chlordane in the samples from the 2001 sampling are far lower than in fish tissue samples from the middle and late 1980s.