Assessment Comments

Fish kill July 20, 1998.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses were assessed as "partially supported."  EXPLANATION:  The assessment of support of the Class B(LR) uses developed for the previous (1998) report ("fully supported / threatened"; see above) was based primarily on results from a DNR stream use assessment conducted in 1991.   The results from this assessment are now considered too old (greater than five years) to be useful for developing water quality assessments of current conditions.   A fish kill occurred on an unnamed tributary to Buck Creek near Ryan in Delaware County on July 20, 1998.   The kill proceeded down the unnamed tributary for approximately four miles into the upper reaches of the Class B(LR) portion of this stream.   The kill was attributed to runoff of animal waste from a dairy operation; an estimated 92,400 fish were killed.   According to DNR's assessment methodology for Section 305(b) reporting, occurrence of a single pollution-caused fish kill within the most recent three-year period (1997-1999) indicates that the aquatic life uses of a waterbody are only "partially supported."  Thus, the assessment of support of the Class B(LR) aquatic life uses was assessed as "partially supported" due to this fish kill.