1938: Sanitary Engineering

The health of a community is largely dependent upon the way its sewage is taken care of. This is being recognized more and more by the public, as evidenced by the large sums of money annually appropriated for sewage-disposal plants.

Among the important plants under construction is the one at Tallman's Island, New York, which will handle sewage from a drainage area of 17,000 acres in the vicinity of New York World's Fair. The plant will have the latest type of equipment, and will include aeration and digestion tanks, grit chamber, also pump and blower house.

The Chicago sewage-purification program has progressed so that it is safe to reduce the diversion of water from Lake Michigan down the Illinois River. Completion of plants now under construction will permit the treatment of 75 per cent of the sewage from an area with a population of 4,587,000 and an industrial load equivalent to 1,800,000 additional population.

Memphis, Tenn., awarded contracts in January 1938 for the building of a single sewer discharging into the Mississippi River to replace the seven previously used.

The Minneapolis-St. Paul Sanitary District sewage plant and tunnels, representing an expenditure of about $16,000,000, was completed in 1938.

One of the largest sewage-disposal projects ever planned in the United States is being constructed at Detroit, Mich. Included is a treatment plant together with some 10 miles of sewers from 9 to 16 ft. diameter, designed to take care of the sewage of a population of 2,400,000. Estimated cost, $22,000,000.

A sewage-disposal plant with novel features was placed in operation at Niagara Falls, N. Y., in the spring of 1938. Here fine screens covered with a 6-in. mat of anthracite coal are employed to partially purify the sewage. The screenings, after being dewatered, are conveyed to sludge incinerators; the plant effluent is treated with chlorine before discharging into the river.

The cities of Atlanta, Buffalo, Columbus, Cleveland, and Denver were engaged on important improvements to their sewage systems. The one at Atlanta includes five disposal plants and 80 miles of sewers, representing an expenditure of $7,000,000.

Further studies were made during the past year on finding a commercial use for sewage. One of the chief obstacles for so doing is the large quantity of liquid that has to be treated to obtain a relatively small amount of salable products. Gas from sludge digestion has been employed for operating engines for pumping, driving fans, and other purposes, while the sludge has been tried as a fertilizer.