Ocheyedan River IA 06-LSR-1638

Assessment Comments

Assessment is based on results of DNR quarterly water quality monitoring near Spencer in FY98 and FY99.

Basis for Assessment

SUMMARY:  The Class B(LR) aquatic life uses were assessed as "fully supported."  EXPLANATION:  The assessment of the Class B(LR) uses was based on results of monitoring during the 1998-1999 biennial period from the DNR quarterly station on the Ocheyedan River near Spencer.   Based on the lack of violations of Class B(LR) criteria for pH, dissolved oxygen, and ammonia in the seven samples analyzed during the biennial period, and due to the lack of violations of Class B(LR) chronic criteria for toxic metals in the two samples analyzed during this period, the aquatic life uses were assessed as "fully supported."  This assessment was based on results of quarterly monitoring.   Results from stations monitored monthly or more frequently, however, are preferred for Section 305(b) assessments in order to improve the accuracy and confidence level of the assessment.   As part of DNR's expanded water quality monitoring program, monthly monitoring at the Spencer station began in October 1999.