Big Sioux River IA 06-BSR-1523

from confluence with Indian Cr. (S9 T93N R48W Plymouth Co.) to confluence with Rock R. in S1 T95N R48W Sioux Co.

This is a Legacy Assessment. Prior to 2004, assessments were developed under a methodology that pre-dated the Integrated Report guidelines.

Assessment Cycle

1994

Result Period

1990 - 1992

Designations

Assessment Type

Monitored

Integrated Report

Category 0

Legacy ADBCode

IA 06-BSR-0010_4

Overall Use Support

Partial

Aquatic Life Use Support

Threatened

Fish Consumption

Not assessed

Primary Contact Recreation

Partial

Documentation

Assessment Comments

Assessment is based on results of water quality monitoring conducted by South Dakota DENR near Alcester, SD, Richland, SD, and Akron, IA.

Basis for Assessment

Over 50% of the approx 12 samples analyzed exceed the Class A WQC for fecal coliforms; thus, assess Class A uses as PS. No violations of Class B WQC; thus suggest FS of Class B uses. Assessed as FST due to known threats from agriculture. 1994 Fishing guide notes that BSR supports fishery for channel catfish. In the 1992 305(b) report, Class A uses were assessed as FS and Class B uses were assessed as PS: this must have been a mistake: STORET retrievals show, even with correction for high flows, approx 45% of the samples exceeded the Class A WQC (= NS). Pattern of highest levels to occur in June, July and August is repeated at all SDAK stations for the years 1990 through 1993.