Mississippi River IA 01-NEM-71

Assessment Comments

Assessment is based on special study of low DO/sediment oxygen demand (Sullivan and Endris 1998) and report on ecological status and trends of the UMR by USGS (1999).

Basis for Assessment

SUMMARY:  The Class A (primary contact recreation) uses remain "not assessed."  The Class B(WW) aquatic life uses remain assessed as "fully supporting / threatened."  Fish consumption uses remain assessed as "fully supported."  The sources of data used for this assessment are (1) Sullivan and Endris (1998) and (2) results of U.S.  EPA/DNR fish tissue (RAFT) monitoring in 1998, 2000, and 2001 downstream from Dubuque.   EXPLANATION:  The Class A uses remain "not assessed" due to lack of information on levels of indicator bacteria in this reach of river.   The Class B(WW) uses remain assessed as "fully supporting / threatened" based on the 1997 study of dissolved oxygen levels by Sullivan and Endris (1998) of the Wisconsin DNR (see assessment for the 1998 report above).   Fish consumption uses remain assessed as "fully supported" based on results of U.S.  EPA/DNR fish tissue (RAFT) monitoring in 1998, 2000, and 2001 downstream from Dubuque that showed levels of contaminants were less than ½ the respective FDA action levels and DNR levels of concern in the composite samples of whole-fish carp in 1998 and 2000 and in the composite samples of fillets from common carp and white crappie in 2001.   In the whole-fish common carp sample collected in August 2000, the level of mercury was less than the detection level of 0.081 mg/kg; the level of total PCBs was 0.295 mg/kg ((Aroclors 1248 (<0.04 mg/kg); 1254 (0.18 mg/kg); and 1260 (0.075 mg/kg)).   In the fillet samples of common carp and white bass collected in August 2001, the levels of mercury were 0.0993 (common carp) and 0.05 (white crappie);  the level of total PCBs in the sample of common carp was 0.131 mg/kg ((Aroclors 1248 (<0.04 mg/kg); 1254 (0.068 mg/kg); and 1260 (0.023 mg/kg)); levels of all three Aroclors were below levels of detection in the sample of white crappie.