3d printed pills to investigate mis-connections

Abstract

Separate sewers are more and more preferred over combined ones but are sensitive to misconnections. Several inspection techniques (time consuming and expensive) are specifically devoted to detecting such misconnections: smoking test and dye tracing are the most popular. This paper presents a new, low-cost and easy to apply method based on 3D printed pills. Numbered (with a unique code) and coloured (blue or red) pills are thrown in toilets, washbowls etc. and then collected in sewers. After an automatic treatment of the collected pills in both the wastewater and the storm water system, the comparison between the sent and collected pill databases allows the identification and the location (inside the building itself) of the misconnections present. Pill and pill analyser designs, analysis methods and on-line tools are described on this paper. Social acceptability and legal issues are briefly discussed.