Iowa River IA 02-IOW-627

Assessment Comments

Assessment is based on results of fish tissue (RAFT) monitoring.

Basis for Assessment

SUMMARY:  The Class A (primary contact recreation) uses and the Class B(WW) aquatic life uses remain "not assessed."  The fish consumption uses remain assessed as "fully supported / threatened."  EXPLANATION:  Similar to the 1998 assessment (see above), assessments of support of the Class A and Class B(WW) uses were not developed due to the potential influences of Iowa City's wastewater treatment plants on results of water quality monitoring from the long-term station monitored by the University of Iowa (under contract with the Army Corps of Engineers) just upriver from the Burlington Street Dam in Iowa City.   That is, water quality conditions in the vicinity of, and downriver from, the wastewater treatment plants are likely not well-represented by a monitoring station located upriver from these plants.   Fish consumption uses remain assessed as "fully supported / threatened" due to results from EPA/DNR fish tissue (RAFT) monitoring in 1999 showing that levels of technical chlordane remain slightly above ½ of the FDA action level.   The composite sample of channel catfish fillets collected from the Iowa River at Iowa City for the 1999 RAFT program contained 0.16 mg/kg of technical chlordane, thus slightly exceeding ½ of the respective FDA action level (0.30 mg/kg).