The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is____________________? August 15, 2021January 22, 2019 by admin The ratio of maximum sewage flow to average sewage flow for trunk mains having diameters more than 1.25 m, is____________________? A. 1.5 B. 2.0 C. 3.0 D. 4.0