Drain water from sludges obtained from sedimentation, septic and Emscher tanks
Photograph of drain water from sludges obtained from sedimentation, septic and Emscher tanks.
This item is part of the 1914 Report on the Collection and Treatment of the Sewage of the City of Philadelphia, which can be viewed here along with two preliminary reports from 1911 and 1912. To see other illustrations from this report, click “1914 Sewage Treatment Plan” in the Subject list.
Three wooden boxes of identical dimensions containing sand in the bottom and a drain pipe were filled with three different kinds of sludge. The right-hand box contained sludge resulting from plain sedimentation; the middle box contained sludge withdrawn from a septic tank; the left-hand box contained sludge withdrawn from a mature Emscher tank. The glasses beneath each drain pipe show the amount of water which drained from each sludge in the same time. It will be noted how the level of the Emscher sludge is much lower than the others, due to its shrinking in volume and the much larger quantity of drain water obtained from it.