Old Mans Creek IA 02-IOW-686

Assessment Comments

Assessment based on results of IDNR biocriteria monitoring in 1994.

Basis for Assessment

Continue to use assessment of support of the Class B(LR) aquatic life uses developed for the 1996 report (=FST); this assessment was based on DNR biocriteria sampling in August 1994.   Used results of fish tissue monitoirng conducted for the USGS National Water Quality Assessment (NAWQA) program to develop the assessment of support of fish consmption uses.   The composite sample of whole-fish carp collected in September 1995 was analyzed for several organochlorine compounds, including chlordane, dieldrin, DDT, and PCBs.   Levels of all contaminants were well-below 1/2 of the respective FDA action levels for these contaminants.   Thus, support of fish consumption uses was assessed as fully supported (FS).   For more information on the USGS fish tissue study, see USGS Fact Sheet FS-027-97 (March 1997).   Reviews of field sheets from DNR stream use assessments in 1991 and from the 1994 DNR biocriteria sampling are inconclusive due to presence of many snags and water too deep to wade and sample (e.g, from 25 to 50% of the reach sampled for the 1994 biocriteria project was too deep to sample).   In general, however, habitat conditions are reported as good due to these conditions:  deep water with snags.   Additional monitoring is necessary to better define the aquatic communities of this stream.   Summary of biological sampling:  DNR stream use assessments, species/families, dstr-> upstr:  4/2, 5/1, 7/2; taxa present vs.  expected:  2 of 8, 3 of 8, 3 of 8; biocriteria sampling:  10 species from 5 families, with 6 of the 8 expected fish taxa present (very few numbers of fish/species reported, with a total of 41 fish over all species).