South Skunk River IA 03-SSK-927

Assessment Comments

Assessment is based on results of (1) IDNR ambient monthly monitoring near Oskaloosa and (2) EPA / DNR (RAFT) in 1999.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses and Class C (drinking water) uses were "not assessed."  The fish consumption uses remain assessed as "fully supported."  EXPLANATION:  The previous assessments of support of the Class B(WW) and Class C uses were based on results from the DNR quarterly monitoring station near Oskaloosa (station 821035).   This station was last monitored from October 1993 through September 1995, and data from this monitoring period are now considered too old (greater than five years) for characterizing current water quality conditions.   As part of DNR's expanded water quality monitoring program, monthly monitoring at the Oskaloosa station began in October 1999.   Results from this monitoring will allow development of an updated assessment of support of beneficial uses for the 2002 report.   Fish consumption uses remained assessed as "fully supported" based on (1) results of USGS/NAWQA fish tissue monitoring near Oskaloosa in September 1995 that showed low levels of organochlorine contaminants (see assessment developed for the 1998 report above) and (2) results of EPA/DNR fish tissue (RAFT) monitoring in 1999 near Oskaloosa that showed levels of all contaminants in the composite sample of fillets from common carp were less than ½ of the respective FDA action levels and DNR levels of concern.