Wolf Creek IA 02-CED-530

Assessment Comments

Assessment is based on results of IDNR ambient monthly monitoring near LaPorte City.

Basis for Assessment

Continued to use assessment of support of the Class B(WW) aquatic life uses developed for the 1994 report (=FST).   Although the assessments of stream fish communities were conducted more than five years ago, the DNR quarterly WQ monitoring station at LaPorte City was monitored within the last five years; thus, consider the assessment category as "monitored."  Also used results of fish tissue monitoring conducted in Sept.  1995 near Dysart for the USGS National Water Quality Assessment (NAWQA) program.   The whole fish composite sample of carp was analyzed for several organochlorine componds, including chlordane, dieldrin, DDT, and PCBs.   Levels of all contaminants in the whole-fish sample were less than one-half the FDA action levels, thus suggesting full support (FS) of the fish consumption uses.   For more information, see USGS Fact Sheet FS-027-97 (March 1997).   In order to better assess support of the Class B(WW) aquatic life uses, used results of a DNR fish survey from April 1990 to support assessment as FST due to (1) presence of a moderately diverse fish community (13 species from 5 families) for streams in the Iowan Surface subecoregion, (2) presence of the expected game fish species (smallmouth bass, although only one 9" individual collected) for streams in this subregion, and (3) presence of a majority of the expected fish taxa (8 of 11) for streams in this region, with all the expected families present (missing taxa were three cyprinid species).  No DNR stream use assessments were conducted in this segment of Wolf Creek; thus, information on threats to continued support is lacking.   Additional monitoring is needed on this lower segment of Wolf Creek to update this assessment, better determine the status of the aquatic communities and habitats, and to determine any signficant threats to the continued support of the Class B(WW) uses.