Corydon Reservoir IA 05-CHA-1331

Assessment Comments

Basis for Assessment

Continued to use the assessments of support of the designated uses for this lake developed for the 1996 report:  (1) Class C (drinking water) uses were assessed as NS due to average levels of atrazine that exceeded the MCL during the period 1990-1994, even though this lake is no longer used as a source of water for the public water supply, (2) Class B(LW) aquatic life uses were assessed as PS due to turbidity related to high levels of siltation and nutrients in the lake, and (3) the Class A (primary contact recreation) uses were not assessed due to lack of information (see 1994 assessment).  Due to the historically high levels of atrazine, this lake was placed on the 1998 list of Section 303(d) waters at the recommendation of the DNR Water Quality Bureau.