French Creek IA 01-UIA-248

Assessment Comments

Assessment based on resutls of (1) 1999-2002 IDNR biocriteria sampling data: 8/8, 3/4, 4/4, 4/4, 4/4, 4/4 coldwater biological indicators met the criteria - Fully Supporting (FS) and (2) EPA/IDNR fish contaminant monitoring in 2002.

Basis for Assessment

SUMMARY:  The Class B(CW) coldwater aquatic life uses remain assessed (monitored) as "fully supported" based on results of biological monitoring   Fish consumption uses are assessed (monitored) as “fully supported” based on results of fish contaminant monitoring in 2002.   Sources of data for this assessment include (1) results of DNR/UHL biological monitoring from 1999-2002 and (2) results of U.S.  EPA/IDNR fish contaminant (RAFT) monitoring near Churchtown in 2002.

EXPLANATION:  The assessment of the Class B(CW) aquatic life uses was based on data collected in 1999-2002 as part of the DNR/UHL stream biocriteria project.   A series of eight (8) coldwater biological indicators, which reflect stream water quality and habitat integrity, were calculated from the biocriteria sampling data and supplemental IDNR Fisheries Bureau data.   The coldwater biological indicators are based on the numbers and types of coldwater benthic macroinvertebrate taxa and fish species that were collected in the stream sampling reach.   Sites that score 7 or 8 are Fully Supporting (FS), sites that score 4-6 are Fully Supporting/Threatened (FS/T), sites that score 2-3 are Partially Supporting (PS), and sites that score 0-1 are Not Supporting (NS).   The 8/1999 coldwater biological indicator score was 8/8, the 7/2000 score was 3/4 (benthic macroinvertebrate only), the 7/2001 score was 4/4, the 9/2001 score was 4/4, the 7/2002 score was 4/4, and the 9/2002 score was 4/4.   The aquatic life use support was assessed (monitored) as fully supporting (= FS), based on a comparison of the coldwater biological indicator score with biological assessment criteria established for this Section 305(b) report.   The coldwater biological indicators were determined from a statistical analysis of data collected at coldwater stream ecoregion reference sites from 1994-2002 and with assistance from the IDNR Fisheries Bureau.

Fish consumption uses are assessed (monitored) as “fully supporting” based on results of U.S.  EPA / IDNR fish tissue (RAFT) monitoring near Churchtown in 2002.   The composite samples of fillets from white sucker and brown trout collected in 2002 had extremely low levels of contaminants.   Neither sample contained levels of contaminants that approached even one-half the respective FDA action levels or IDNR levels of concern.   Levels of primary contaminants in the composite sample of white sucker fillets were as follows: mercury: 0.022 ppm; total PCBs: <0.09 ppm; and technical chlordane: <0.03 ppm.   Levels of primary contaminants in the composite sample of brown trout fillets were as follows: mercury: 0.028 ppm; total PCBs: <0.09 ppm; and technical chlordane: <0.03 ppm.