This document is the case study for Portland ME West Side Interceptor. SaniTite HP was chosen over concrete and polymer for combined sewer overflows.

The City of Portland needed to eliminate combined sewer overflows and keep untreated wastewater from flowing into an estuary. The new line replaced dual lines of vitrified clay and SaniTite HP was the choice over epoxy-coated reinforced concrete and centrifugally-cast glass fiber reinforced polymer.

In order to replace the dual lines, 60” (1500 mm) SaniTite HP was chosen. This allowed the contractor to use both 16’ (4.8 m) and 20’ (6.0 m) depending on the circumstances of the installation, which included power lines overhead and areas where the installation was deeper than other areas. In addition, 24”-48” (600-1200 mm) SaniTite HP pipe was used for lateral runs. To connect the laterals to the main pipe, Inserta Tees were utilized for a quicker installation.

This was one of the nation’s first installations of polypropylene pipe and the contractor was pleased as SaniTite HP was easier to install than concrete pipe. The light weight only required use of a backhoe and not a crane and fewer trucks were needed because of longer lay length. Months later Mandrel testing determined there were no issues and the pipe maintained its shape.

The installation was done in June-October 2010 using 5,600’ (1706 m) of 60” (1500 mm) SaniTite® HP, 200’ (61 m) of 24”-48” (600-1200 mm) SaniTite HP and Inserta Tee ® lateral connections.

Photographs of the project are included.