- ENGINEERING INFO
- CASE STUDIES
After numerous emergency repairs to a 40-plus year old 8" cast iron water main along Snell Isle Boulevard, John Riera, Water Resources Manager for the City of St. Petersburg, decided it was time to replace a 1,200 LF section. Corrosion caused by tidal influenced groundwater had rendered the cast iron water main unreliable and a candidate for replacement.
The City routinely replaces old water distribution lines using in-house personnel and equipment, typically by open-cut or by utilizing City crews capable of horizontal directional drilling. In the case of the section along Snell Isle Boulevard, the water line was buried approximately three feet beneath manicured front yards and crossed more than two dozen driveways making open cut replacement expensive and inconvenient to homeowners. Being aware that other municipalities throughout the state had successfully replaced water distribution lines using pipe bursting, John Riera and Senior Engineer David Abbaspour decided to evaluate pipe bursting with Fusible PVC® pipe. Project design challenges included the shallow depth of the line and approximately 30 connections.
Following a joint meeting and site inspection in February 2009 by the City, WRS Compass, and Underground Solutions, Inc. (UGSI), a plan was established to pipe burst two 600 LF segments using 8" Fusible C-900® DR18 pipe. WRS Compass was contracted to perform the pipe burst, while UGSI was to provide pipe and fusion services. City personnel performed all other related construction, including installation of a temporary bypass line, pit excavations, and pipe and service connections.
John Riera reported: "The job was completed under budget, and homeowners were pleased with the speed and minimal disruption. We'll definitely consider pipe bursting with Fusible PVC® pipe on future projects." Troy Freed, WRS Compass Director of Trenchless Technologies, commented: "Fusible PVC's ID/OD advantage over HDPE is beneficial, especially so when bursting shallow pipe under driveways." David Abbaspour added: "Ease of connecting and tapping Fusible PVC® pipe was a definite benefit to our crews. UGSI and WRS Compass definitely delivered as promised."