Resident-specific metrics in the context of wastewater treatment plant sizing and plant comparisons

Abstract

The draft of the DWA Code of Practice A 198 [1] results in a change in the specific characteristic values included. In the previous version, these were shown as 85% percentiles, although the usual application practice before that was based on the same numerical values as mean values. Recent evaluations show that the original (mean) values correspond more to reality. However, this results in friction points in the application of the rules due to this change. This article describes the background of the original development, the resulting obstacles and gives recommendations for future use.