Fusible PVC® pipe for fault crossings, curvilinear alignments and restrained joint sections

The Los Carneros Water District Recycled Water Project was designed to provide the Los Carneros Water District (LCWD) service area, located just south of Napa, California, with a reliable recycled water supply. This system is used to offset groundwater use during the summer irrigation season allowing more potable water to be available for critical consumption.

This project included the construction of 8.6 miles of 6- to 20-inch diameter recycled water pipelines to provide a distribution system which supplies recycled water to portions of residential landscape and agricultural land within LCWD. The recycled water will be sourced from the Napa Sanitation District’s existing Soscol Wastewater  Treatment Plant (WWTP). The system is located within existing road right of ways and did not require new pump stations or storage facilities. All storage and pumping requirements are met using Napa Sanitation District’s Soscol WWTP facility. The project serves approximately 115 parcels or 3,800 acres of irrigable land within the District with approximately 1,300 acre-feet of recycled water per year. Irrigation water users connect their own irrigation systems and facilities to various turnouts on the system to provide the recycled water to their private lands and fields.

The District bid Fusible PVC® pipe, with its thermally butt-fused joint, as the base bid for restrained joint areas, fault crossings and curvilinear alignments that exceeded the allowable deflection of conventional bell-and-spigot pipe. The District also allowed mechanically restrained bell-and-spigot PVC pipe, using bell restrainers with 316 stainless steel hardware for the restrained pipe lengths. The bell restrainer also needed to be wrapped in an AWWA approved four-part petrolatum tape wrap system for corrosion control. JMB Construction, the low bidder on the project, elected to use Fusible PVC® pipe in the restrained areas as the most cost-effective option.

Approximately 20 percent of the pipeline was constructed with Fusible PVC® pipe. Fusible PVC® pipe addressed several specific design elements that conventional bell-and-spigot PVC pipe could not. These included seismic fault crossings where the fusion joint provides a fully restrained joint that resists ‘pull-out’ during earth movement. It also included curvilinear horizontal and vertical pipeline alignments that
exceed the allowable deflection capability of bell-and-spigot joining technology. Finally, it was used as the non-corrosive restrained-joint pipeline required to resist axial thrust at fittings and appurtenances along the pipeline. Fusible PVC® pipe is the only PVC restrained joint meets the requirements of the AWWA C605 PVC pressure pipe installation standard, regardless of pipe size.

JMB Construction’s Sean Quinn commented, “JMB has utilized and installed Fusible PVC® pipe on many projects including HDD, sliplining, pipe bursting and open cut installations. This is another project in a long line of successful projects using Fusible PVC® pipe.”

Image 1: Placing the restrained, Fusible PVC® pipe length under existing utility crossings
Image 2: JMB used standard, mechanical joint ductile iron fittings with restrainer glands to assemble the pipe system