Assessment Comments

Assessment is based on results of EPA/IDNR fish tissue (RAFT) monitoring in 1998 and 2000. See attached document for details.

Basis for Assessment

[Note:  For the 2002 report, the previous waterbody segment for the Des Moines River (IA 04-LDM-0010-0), which extended 76 miles from its mouth to the confluence with Soap Creek near Eldon (Wapello Co.), was split into four subsegments:  (1) mouth (Lee Co.) to the Sugar Creek Keokuk (IA 04-LDM-0010-1), (2) Sugar Creek to Indian Creek near Farmington, Van Buren Co.  (IA 04-LDM-0010-2), (3) Indian Creek to Chequest Creek near Keosauqua, Van Buren Co.  (IA 04-LDM-0010-3), and (4) Chequest Creek to Soap Creek near Eldon in Wapello Co.  (IA 04-LDM-0010-4).   See assessment documentation for segment IA 04-LDM-0010-2 for previous Section 305(b) assessments for the original 76-mile river reach.]

SUMMARY:  The Class A (primary contact recreation) uses and Class B(WW) aquatic life uses are "not assessed."  Fish consumption uses are assessed as "fully supported."  The source of data for this assessment is the results of U.S.  EPA/IDNR fish tissue monitoring in 1998 and 2000 at Keosauqua.   EXPLANATION:  The Class A uses and Class B(WW) uses were not assessed due to the lack of water quality monitoring and other water quality information for this river segment upon which to assess support of these uses.   Prior to the 2002 report, these uses were assessed based on results of water quality monitoring conducted near Keokuk (see assessments for the 1998 and 2000 reports above).   This monitoring station is more than 30 miles downriver from the current assessment segment (IA 04-LDM-0010-3), and previous assessment likely represent an excessive extrapolation of the monitoring results from the Keokuk station.   Results of EPA/DNR fish tissue (RAFT) trend monitoring near Keosauqua in 2000 showed that levels of all contaminants in the composite sample of whole-fish common carp were well below U.S.  FDA action levels and IDNR levels of concern.   The level of technical chlordane in this sample (0.100 ppm) was much lower than that in the sample from this station in 1998 (0.29 ppm).   Due to this significant (66%) decline in the level of chlordane, the support of fish consumption uses was changed from "fully supported /threatened" to "fully supported."