inches deep at the lower end. At the upper end of the bed the channel is paved with brick, and the stone is banked up over the lower edge of this pavement in such a way as to form a 'headbay' into which the siphon discharges the contents of the coke bed. "The operation of the channel is very simple. The siphon is proportioned to discharge the contents of the coke bed somewhat more rapidly than the broken stone can receive it, thus building up a pressure head in the head-bay whereby the upper end of the stone bed is charged to its full depth. Thus a wave of sewage is started at the head of the channel through a body of porous material, and traverses the channel throughout its length (60 feet), declining somewhat in vertical amplitude as it progresses. The effective result is that the sewage passes through 60 feet of filtering material, being divided, subdivided and redivided by the porous material through which it flows, so that every drop of it comes into intimate contact with well aerated surfaces; and that every vertical transverse section of the bed is subjected to an intermittent rise and fall of sewage, thus providing frequent aeration alternating with frequent application-an ideal condition. Although the effective depth of the bed is 60 feet, no particle of the filtering material is more than 18 inches distant from free air. Aeration is therefore thorough and rapid. The passage of all the waves being similar in time and character, the bacterial colonies are accurately self-stratified-a condition which the experiments of Scott Moncrief and Colonel Waring have shown to be of great importance. "The actual chemical change which takes place in the sewage while passing through these aerating channels, though marked, is not of so much importance as is the charging of the effluent with oxygen, practically to the point of saturation. "The coke in the coke beds and the stone in the channels will be a few inches deeper than the maximum depth of sewage. This affords protection from light, which is deterimental to bacterial growth; it tends to conserve the heat and to preserve a more uniform temperature, and it keeps the sewage practically out of sight until it escapes in the effluent outfall, a finished product. In the winter the head-bays are covered with light wooden covers, and the coke and stone filters are bedded with marsh hay, or similar material, to be raked off in the spring. "The following analyses, taken from records of tests made last year, show the best and the worst results obtained under the use of this system, and indicate fairly its average performance: "Indeed these results are rather worse than they should be, because the regular operation of the plant was interrupted at times for experimental purposes the dose being suddenly increased or diminished, etc. "The system has been approved by the New Jersey state sewerage commission for use at Collingwood, N. J., and by the Ohio state board of health for installation at Kenton, Ohio. Respectfully, 66 "CITY WASTES DISPOSAL COMPANY" HAVERSTRAW, N. Y. Separate sewer system Plans providing for a complete sewer system for the village were approved by this Board July 10, 1900. These plans are to take the place of those adopted by this Board July 27, 1893. PLATTSBURG, N. Y. Changes and extension of existing sewer system Plans providing for slight changes in the existing sewer system and for various extensions aggregating 10,435 lineal feet of new sewers were approved by this Board July 10, 1900. These discharge into Lake Champlain direct and no disposal works are contemplated at present. WHITE PLAINS, N. Y. Storm water sewer Plans providing for a storm-water sewer through and along Davis brook from the New York post-road to the west side of Bronx street, a distance of about 4000 feet, were approved by this Board July 10, 1900. From the end of this sewer, which con stitutes a change in the plans heretofore approved, the collected storm water will flow through Davis brook about 350 feet to its junction with the Bronx river. BATH, N. Y. Jail sewer Plans for an 8-inch vitrified pipe sewer from the Steuben county jail to the Cohocton river, a distance of 1695 feet, were approved by this Board September 20, 1900. |