Assessment Comments
Monitoring by LTRMP staff, Bellevue station.
Basis for Assessment
[NOTE: For the 2002 report, Shrickers Slough was separated from the assessment for Rock Creek. In previous reports, both waterbodies had been assessed as one assessment unit. Thus, the following assessments for Shrickers Slough for the 1996, 1998, and 2000 reports have been developed from the respective assessments originally developed for the combined "Rock Creek/Shrickers Slough" waterbody. In order to make these assessments specific to Shrickers Slough, several deletions and additions were necessary; however, no substantive changes were made. For the unedited original assessments developed for the combined Rock Creek/Shrickers Slough waterbody, see assessment information for lower Rock Creek, segment IA 01-MAQ-0010-1).]
SUMMARY: The Class A (primary contact recreation) uses were "not assessed." The Class B(WW) aquatic life uses are considered "fully supported/threatened." Fish consumption uses were "not assessed." The source of data for this summary is monitoring conducted approximately twice per month at Shrickers Slough by staff of the Upper Mississippi River Long-Term Resource Monitoring Program (Bellevue Office) from December 1999 through November 2001. SUMMARY: The designated uses for Shrickers Slough are those given to the adjoining Mississippi River (i.e., Class A,B(WW)). No attempt was made to assess this wetland for support of primary contact recreation. The Class B(WW) uses were assessed as "fully supported/threatened" based on results of monitoring that show 10 of the 50 surface samples analyzed for dissolved oxygen exceeded the Iowa water quality criterion of 5 mg/l for protection of Class B(WW) uses. According to U.S. EPA guidelines for Section 305(b) water quality assessments (U.S. EPA 1997b, page 3-17), a violation frequency of 10% is on the border between "full support and impairment of the aquatic life uses. Thus, these uses were assessed as "fully supported/threatened" such that nonsupport of these uses is likely to occur over the next two years. Only one of 50 samples violated the Iowa water quality criterion for pH. According to U.S. EPA guidelines for Section 305(b) asssessments, this frequency of violation (2%) does not indicate a water quality impairment. None of the 44 surface samples analyzed for ammonia-nitrogen exceeded the Class B(WW) water quality criteria. Fish consumption uses were not assessed due to lack of fish contaminant monitoring in this backwater of the Upper Mississippi
