Shell Rock River IA 02-SHL-786

Assessment Comments

Assessment is based on results of water quality monitoring.

Basis for Assessment

Used results of the monthly WQ monitoring station near Gordonsville operated by the Minnesota Pollution Control Agency to develop assessments of use support.   The Class B(WW) aquatic life uses were assessed as FS due to the lack of violations of WQ criteria for either toxic or conventional pollutants in the 18 samples collected during the Oct 95-Sep 97 period.   Considered the Class A primary contact uses as "not assessed" due to lack of data:  data for fecal coliforms not reported in STORET for the Gordonsville station since September 1994.   The March/April 1998 edition of the Iowa Conservationist notes that smallmouth bass populations have recovered in this river, with the reach in Cerro Gordo county providing good angling opportunities.   DNR received a citizen complaint in June 1997 regarding "pea soup green" conditions in this reach of river.   The citizen was familiar with the pollution history of the Shell Rock, but he had noticed a general decline during the years 1995 to 1997.   DNR Fisheries feels that the WQ of the river has improved through the 1990s and that the river tends to run "green" in summer.