Mississippi River IA 01-NEM-61

Assessment Comments

Assessment is based on fish tissue monitoring (RAFT) near Muscatine in 1999 and 2001 and near Buffalo (Scott Co.) 1998 and 2000. See attached document for details.

Basis for Assessment

SUMMARY:  The Class A (primary contact recreation) uses and the Class B(WW) aquatic life uses remain "not assessed."  Fish consumption were assessed as "fully supported."  The data used for this assessment are from results of the U.S.  EPA/DNR (RAFT) fish tissue monitoring program near Buffalo, Iowa, in 1998 and 2000 (trend monitoring) and near Muscatine in 1999 and in 2001 (status monitoring) note:  the RAFT trend monitoring site near Linwood was moved downriver to Buffalo in 1998).  

EXPLANATION:  The Class A (primary contact recreation) uses and the Class B(WW) aquatic life uses remain "not assessed" due to lack of monitoring information for this river reach.   Results of EPA/DNR fish tissue (RAFT) monitoring on the Mississippi River near Buffalo 1998 and 2000 showed that levels of all contaminants in the two samples of whole-fish carp were below the respective FDA action levels.   The 1998 sample contained 0.16 mg/kg of technical chlordane; this level is slightly above ½ of the FDA action level of 0.30 mg/kg; the level of technical chlordane in the 2000 sample was much lower at 0.064 mg/kg.   According to DNR's assessment methodology for Section 305(b) reporting, levels of fish contaminants greater than ½ of the respective FDA action level indicate that fish consumption uses should be assessed as "fully supported / threatened."  In addition to this trend (whole-fish) sampling, EPA/DNR (RAFT) status (fillet) monitoring conducted downstream from Muscatine in 1999 and 2001 showed that levels of all contaminants in composite samples of fillets from common carp, black crappie, and white crappie are well-below ½ of the respective FDA action levels and DNR levels of concern (see also asssessment for the 2000 report above).   The only contaminant detected in the composite samples of fillets from common carp and white crappie from 2001 was mercury (0.129 mg/kg and 0.108 mg/kg, respectively).   Based on this information, fish consumption uses were assessed as "fully supported."