Experimental investigations by the State Board of Health of Massachusetts upon the purification of sewage by filtration and by chemical precipitation and upon the intermittent filtration of water. Made at Lawrence, Mass., 1888-1890.

  • Massachusetts. State Board of Health.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Experimental investigations by the State Board of Health of Massachusetts upon the purification of sewage by filtration and by chemical precipitation and upon the intermittent filtration of water. Made at Lawrence, Mass., 1888-1890. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    The iron pipe follows the sewer to its outlet, and then rests upon the bed of the river for three thousand feet, then extends three hundred feet within the filtering grounds, entering the building and running along by the side of the drain. The sewage is raised by two pumps Q;. p.) into two measuring basins {m. i.), (m. h.), within the building at a higher level than the top of the filtering tanks, where the quantity to be put upon any tank is noted by a scale of heights indicating gallons, and is distributed, by movable hose, to either of five tanks from one measuring basin, and to the other five tanks from the other measuring basin. Besides these large filtering tanks, there have been placed within the building ten galvanized iron tanks having about the same depth, but a diameter of only twenty inches, giving an area of surface one- hundredth of that of the large tanks, or one twenty-thousandth of an acre. These tanks are numbered from eleven to twenty. Each has a sloping bottom and a faucet placed low enough to completely drain the bottom. On the bottom of each is placed coarse gravel, covered with finer gravel and coarse sand to a depth of five inches, as in the larger tanks. Upon these layers, common to all, there was put into No. 11 three feet and eight inches of material like that in No. 6. Tanks numbered 12, 13, 14 and 20 were filled’to a depth of five feet with coarse sand like that of No. 1 ; and tanks numbered 15, 16, 17 and 18 were filled with sand and peat, taken from the Saugus Marshes. In the field beyond the filter tanks the area of about one-third of an acre is sloped in the direction from the line of tanks about one foot in ten feet, and in the direction parallel with them about one foot in one hundred feet. This area is laid out in shallow drains to receive sewage for filtration, underdrains being placed sixty feet apart, to catch samples of the effiuent. These underdrains are put at the depth of four feet, and slope like the surface, — one foot in ten feet, — being about fifty feet in length, opposite tanks Nos. 3 and 8, and opposite the space between Nos. 5 and 6. Trenches were cut two feet wide and the bottom coated with two inches of puddling clay, plastered on, a little lower in the middle, where the two-inch drain tile was laid with open joints, and sur- rounded with six inches in depth of gravel. The surface drains are in the material of the field, which for several feet in depth is a fine river silt, which freezes about as