Cedar River IA 02-CED-470

Assessment Comments

Assessment is based on results of (1) IDNR ambient city monitoring upstream from Cedar Falls and (2) U.S. EPA/IDNR fish tissue (RAFT) monitoring in 1997.

Basis for Assessment

SUMMARY:  The Class B(WW) aquatic life uses were assessed (monitored) as "fully supported" based on results of IDNR ambient monitoring from 2000-2002.   Fish consumption uses remain assessed (evaluated) as "fully supported" based on results of fish contaminant monitoring in 1997.   The sources of data for this assessment are (1) the results of monthly monitoring from January 2000 through December 2002 at the IDNR ambient city monitoring station located at upstream from Waterloo at the old highway 218 bridge at Cedar Falls and (2) the results of U.S.  EPA/IDNR fish tissue (RAFT) monitoring at Cedar Falls in 1997.  

EXPLANATION:  The Class B(WW) aquatic life uses were assessed (monitored) as "fully supported" based on results of monitoring from the IDNR ambient station at Cedar Falls from 2000 through 2002.   Monitoring at this station showed no violations of Class B(WW) water quality criteria for dissolved oxygen, pH, ammonia-nitrogen, toxic metals, and toxic organic compounds in the 14 samples analyzed during this assessment period; no detected levels were reported in the nine samples from this station analyzed for pesticides.   Fish consumption uses remain assessed as "fully supported" based on results of U.S.  EPA/IDNR fish tissue (RAFT) monitoring at Cedar Falls in 1997 that showed levels of all contaminants were less than ½ of the respective FDA action levels and IDNR levels of concern (see assessment for the 2000 and 1998 reports).   However, because these data are now considered too old (greater than five years) to accurately characterize current water quality conditions, the assessment category is changed from "monitored" (indicating an assessment with relatively high confidence) to "evaluated" (indicating an assessment with relatively lower confidence).