Effectiveness of Inlet Control in Solving Combined Sewer Problems: A Case Study

Environmental Engineering Research 1996;1(2): 131-138.

¹Dept. of Civil Engineering, Korea Advanced Institute of Science and Technology, Taejon 305-701, Korea
²Harza Consulting Engineers and Scientists., 233 S. Wacker Dr., Chicago, IL 60601, USA

Received: July 13, 1996; Accepted: September 13, 1996.

ABSTRACT

Cities with combined sewers face two basic problems: street flooding and basement backup. Inlet control devices coupled with other measures can potentially solve these problems at lower costs than traditional solutions. Real data from a completed project of inlet control in the City of Evanston (Illinois, US.A) demonstrates that the concept can be effective in mitigating these problems in both terms of technicality and cost. The project shows that a 100-year level of protection against basement backup can be achieved using inlet control on a combined sewer system. Simultaneously, protection against street flooding can be increased to an acceptable level. The cost of inlet control approach is approximately 50% of the cost of traditional approaches. Based on this successful results, the City is proceeding with all phases of the plan with confidence.

Keywords: Inlet ontroL | Combined Sewer | Combined Sewer Overflow | Urban Flooding | Overland Flow