SEI Sewer

WestLand Resources completed a route study and a design for the relocation and upsizing of the Pima County Regional Wastewater Reclamation Department (PCRWRD) Southeast Interceptor that helps convey flows from as far southeast as Vail, Arizona to the Agua Nueva WRF.  The interceptor is located with both the Cities of South Tucson and Tucson with a high density of business including several restaurants and historic neighborhoods. The route selected utilized the historic SPRR now UPRR railroad alignment to avoid running the interceptor through the urban development.  The alignment included going through streets with many existing utilities, the design of two biofilters for odor abatement, eleven jack and bores to avoid roadway cuts as well as large utilities and high pressure gas lines. The sewer trunk main ranged from 30” to 60” and has the capacity to convey 14.5 MGD.  The RWRD used full fiberglass manholes for the first time which created challenges of the entire manhole and base being built off site which required the inlet and outlet inverts to be precise to maintain slopes which were minimal at some locations. Another challenge was the amount of utilities located in 36th Street which required the Contractor to be very timely on the roadway shut downs and use additional jack and bores to avoid closing major streets.

This project marked the first RWRD project required to provide a set aside for art.  Using this opportunity to get the surrounding area involved, children in the area submitted drawings that were then 5 were selected to create castings and put onto manhole lids used on the project.  This project won the Metropolitan Pima Alliance Common Grounds Award for a public project working with the community.