Assessment is based on results of IDNR ambient monthly monitoring NW of Cedar Falls. See attached document for details.
Basis for Assessment
SUMMARY: Assessed support of the Class B(WW) aquatic life uses as "fully supported." Fish consumption uses remained "not assessed." Sources of data for this assessment include the IDNR monthly ambient monitoring station at the county road T75 bridge approximately 3.5 miles northwest of Cedar Falls.
EXPLANATION: Results of DNR monthly water quality monitoring from the station located NW of Cedar Falls during the 2000-2001 biennial period showed no violations of water quality criteria to protect the Class B(WW) aquatic life uses. That is, no violations of state water quality criteria conventional parameters (dissolved oxygen, pH, and ammonia-nitrogen) occurred in the 24 samples collected during this monitoring period; levels of toxic metals were below levels of detection in the four samples analyzed, and levels of pesticides were below levels of detection in the 6 samples analyzed during the biennial period. The assessment of support of the Class B(WW) aquatic life uses developed for the 1994, 1996, 1998 and 2000 reports (fully supported/threatened) was based entirely, or in part, on stream fish survey or habitat information from 1992 (see assessments for previous Section 305(b) reporting cycles above). These data are now considered too old (greater than five years) for accurately characterizing current water quality conditions. Fish consumption uses remain "not assessed" due to the lack of recent fish contaminant monitoring in this stream reach.