March 10, 1909: Municipal Journal and Engineer article. Water Filtration and Sedimentation—Settling Reservoirs. “In a paper presented in January before the Institution of Mechanical Engineers (England), Mr. John Don reviewed the subject of water purification in a very comprehensive way; and the Institution has published an excellent abstract of the paper, from which we select the following, as of special interest to American Water Works Superintendents and Engineers.
It is usual in America to have three or four compartments arranged either in a rectangular form or in a crescent. From the raw-water basin the flow takes place over a dividing wall into the next, and so on. At the Paris water works of the Compagnie Generate, the settling tanks are so constructed as to induce continuous and progressive sedimentation. The process here is threefold. First the path of the water lies through a series of narrow troughs disposed in zigzag form, in which the heavier particles are thrown down. Following the troughs comes a sequence of larger compartments and finally decanting basins, and in both of these the alternating left to right and also up and down movements induce still further precipitation. The combined effect of these slow and regulated and tortuous movements is that the sedimentation is more rapid than if the water were left stationary. It is also conducted within a much less area and with far less depth than would be necessary if mere stagnation were depended upon to produce a like result.
Notable for its ingenious construction is the Sunridge Park covered reservoir, which is laid out in concentric channels. From the plan it will be seen that the water circulates first in one direction and ·then backwards in the next conduit inwards. There is a slight fall from the periphery to the center, where the outlet is placed.”
Reference: “Water Filtration and Sedimentation—Settling Reservoirs.” Municipal Journal and Engineer article 26:10(March 10, 1909): 408.
Commentary: Now THAT is what I call a baffled reservoir. No short-circuiting allowed here.