Middle River IA 04-LDM-1086

Assessment Comments

Assessment is based on results of (1) DNR/UHL biocriteria sampling in 1998 (Fish IBI= 46(fair), BM-IBI= 60(good) and (2) fish tissue (RAFT) monitoring at Pammell Park in 1996.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses were assessed as "fully supported / threatened."  Fish consumption uses remain assessed as "fully supported."  EXPLANATION:  The previous assessment of support of the Class B(WW) uses was based on results DNR fish surveys conducted in Madison County in October 1990.   The results of these surveys are now considered too old (greater than five years) to be useful for assessing current water quality conditions.   The current assessment is based on results of a DNR/UHL biocriteria sampling of fish and benthic macroinvertebrates in 1998.   Based on a comparison to results of ecoregion reference site sampling, the fish community was rated "fair" (Fish IBI=46)  while the benthic macroinvertebrate community was rated "good" (MB IBI=60).   These results suggest that the Class B(WW) uses are "fully supported / threatened."  Fish consumption uses remain assessed as "fully supported" based on results of EPA/DNR fish tissue (RAFT) monitoring in 1996 that showed levels of all contaminants in the composite sample of fillets from channel catfish were less than ½ of the respective FDA action levels and DNR levels of concern (see assessment developed for the 1998 report).