Optimal Operation of the Little Rock Wastewater Collection System

A system evaluation and capacity assurance plan (SECAP) was completed in 2002 for the Little Rock Wastewater Utility (LRWU), Little Rock, Arkansas. The LRWU service area, corresponding to the SECAP study area, is composed of six basins. The utility provides service to over 60,000 customers and maintains over 1,770 kilometers of collections system lines for the greater Little Rock area. A fully dynamic hydraulic model was built using the Wallingford software InfoWorks program to simulate operation of the LRWU wastewater collection system. This hydraulic model contains pump stations, force mains and gravity lines 25.4 cm in diameter and greater. The hydraulic model was used to identify hydraulic capacity deficiencies during the design wet weather event. The proposed solution to these deficiencies included sewer line and treatment facility upgrades, in addition to the design and construction of a 114,000 m³ flow equalization storage facility.