Biennial Water Quality Assessment

ORSANCO completes an assessment and report of Ohio River water quality conditions every two years, otherwise known as the “305b Report.”  Water quality data are compared to water quality criteria (or goals) over a two-year period to determine if the Ohio River meets its intended uses (suitable to support aquatic life, contact recreation, public water supply and fish consumption).  Generally, waters that do not meet these uses are required to have a total maximum daily load (TMDL).  ORSANCO completes the report on behalf of the mainstem states every two years.


Most Recent 305b Report Download