. Public works . the three bottoms of each tank. The main walls nithe tanks are constructed of reinforced concrete, sup-ported by structural steel frames. Provision is made snthat any one of the five tanks can be emptied while theothers are in service. From the Imhoft tanks the effluent will pass over weirsand through two 30-inch cast iron dosing siphons in-stalled in dosing tanks. These siphons will automaticallyregulate the flow of sewage onto the filters. The filtersare 223 feet by feet and are designed to care for thesewage of about 40,000 people. The floor is made ofconcrete with Cli
. Public works . the three bottoms of each tank. The main walls nithe tanks are constructed of reinforced concrete, sup-ported by structural steel frames. Provision is made snthat any one of the five tanks can be emptied while theothers are in service. From the Imhoft tanks the effluent will pass over weirsand through two 30-inch cast iron dosing siphons in-stalled in dosing tanks. These siphons will automaticallyregulate the flow of sewage onto the filters. The filtersare 223 feet by feet and are designed to care for thesewage of about 40,000 people. The floor is made ofconcrete with Clinton wire reinforcement, having troughsor channels with curved section 3 inches deep and 11inches in span. The thickness of concrete under thedeepest part is 3 inches. Over these channels are placedbrick made of one part cement to two parts stonecrusher dust, 17 inches long, 1;^ inches thick and 4 inchesdeep. The bricks are placed on edge spanning the chan-nels so that those over each channel overlap those on the. INTERIOR , adjacent channels 2 inches, thus keeping all bricks prop-erly spaced. This form of floor construction gives about40 per cent of air space and is expected to increase theefficiency of the filter. Over these bricks is laid a layerof 2-inch cobblestones about 3 inches deep and on top ofthese is placed the broken stone, which is laid 10 feetdeep. Both local granite and trap rock have been used,in sizes from one to two inches. Through the center of the filter, covering a length of405 feet, is built a flushing gallery with a port hole toeach channel to allow for such inspection and flushingas may be necessary. The channels have a slope of 6
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Keywords: ., bookcentury1800, bookdecade1890, bookidpublicworks3, bookyear1896
