Technical Bulletin No. 0453: Intralaboratory Precision of the Five-Day Biochemical Oxygen Demand Test

Five-Day Biochemical Oxygen Demand, the subject of this technical bulletin, is universally used for measuring the organic strength of effluents and the quality of surface waters. The procedure was introduced in 1917 as a standard method and, during the 70 following years, has survived as a vital measurement in the environmental arena. The procedure continues to have important application in (a) monitoring treatment plant performance, (b) rational design of biological treatment facilities, (c) management and assessment of receiving water quality and, (d) as a National Pollution Discharge Elimination System (NPDES) compliance parameter.