A study was made of the effect of sewage distribution on the efficiency of high rate sewage filters at Neosho, Missouri. The Neosho municipal sewage treatment plant has two parallel, high-rate filters of the Aerofilter type and was designed for a population of 12,000 and a population equivalent of 22,500, the industrial wastes consisting principally of the wastes from a large milk condensery. The first period of study extended from March 19 to April 11, 1945, and the second from July 12 to August 8. Twenty 24-hour composite and five 4-hour composite samples were collected and analyzed from each sampling point during the first period and twenty-four 24-hour composite and two 4-hour composite samples during the second. In addition, grab samples were collected for analysis during both periods for dissolved oxygen, B.O.D. of the digester supernatant, and special determinations.