(Little Rock, AR) On Thursday, July 23, 2009, Little Rock Wastewater (LRW) and CDM, Inc. will hold a Ribbon Cutting Ceremony for the Peak Flow Attenuation Facility in Southwest Little Rock. The purpose of this project is to improve the hydraulic capacity of the collection system during heavy rain and address wet weather sanitary sewer overflows in the western end of the Fourche Bottoms.

LRW is required to reduce sanitary sewer overflows in Little Rock because of the settlement agreement between the utility and the Sierra Club. The Peak Flow Attenuation Facility project is designed to handle a storm where five inches of rain would fall within 48 hours, which is also referred to as a ‘peak flow event.’

At a cost of nearly $33 million, the project consists of constructing a 50 MGD pump station near Mabelvale Pike, 11,500 linear feet of force main pipe, two diversion structures and a 30 million gallon storage facility (a 10 million gallon and a 20 million gallon concrete structure. The detention basins will store water generated by rain fall and then discharge into the collection system when flows return to normal. The Arch Street Pump Station rehabilitation and hydraulic upgrade project is being constructed simultaneously with the Peak Flow Attenuation Facility project. These projects complement each other in that they both enhance the hydraulic conveyance capacity of the sanitary sewer system through the Fourche Creek Bottoms, thereby reducing sanitary sewer overflows during wet weather events.

LRW intends to install a parallel force main to be used in combination with the existing force main during peak flow events. By utilizing both the existing force main and the new parallel force main, the internal pressure during a peak flow event can be minimized.

LRW engineers estimate that the Peak Flow Attenuation Facility will only be utilized 10 to 15 times annually.

This is the largest project to be completed thus far under LRW’s $338 million capital projects plan. LRW is also constructing a wastewater treatment facility in West Little Rock and preparing to increase the hydraulic capacity at the Fourche Creek Treatment Facility.

Planned speakers for the event include Mayor Mark Stodola, and other members of the Little Rock Board of Directors.

For additional information, contact Joseph Schaffner at 501-688-1449 or by email at joseph.schaffner@lrwu.com.