Assessment Comments

Assessment is based on results of IDNR ambient monthly monitoring near Oakland Mills in 2000 and 2001.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life are assessed as "fully supported."  Fish consumption uses are "not assessed."  The source of data for this assessment is the results of IDNR ambient monthly monitoring during the 2000-2001 biennial period at station 10440001 approximately 3 miles southwest of Oakland Mills (formerly station number 821004).   EXPLANATION:  The Class B(WW) aquatic life uses were assessed as "fully supported."  None of the 24 samples collected during the 2000-2001 biennial period at the IDNR monthly station violated Class B(WW) water quality criteria for pH, dissolved oxygen, or ammonia-nitrogen; no violations occurred in the four samples analyzed for toxic metals or in the six samples analyzed for pesticides and other toxic organic compounds.   Although the Class B(WW) uses were assessed as "threatened" for the 1998-1999 biennial period due to a single violation of the chronic Class B(WW) criterion for chlorpyrifos (see assessment for the 2000 report above), none of the six samples analyzed during the 2000-2001 biennial period contained a detectable level of chlorpyrifos.   Thus, the assessment of the Class B(WW) uses was changed to "fully supported" (not threatened) for the 2002 report.   Fish consumption uses were "not assessed" due to the lack of recent fish contaminant monitoring in this stream segment.   The most recent monitoring was conducted as part of USGS/NAWQA fish tissue monitoring near Oakland Mills in September 1995 (see assessment for the 1998 report).   Results from this monitoring are now considered too old (greater than five years) for characterizing current water quality conditions.