- ENGINEERING INFO
- CASE STUDIES
The North Marin Water District (NMWD) in northern Marin County relies on imported Russian River water for 80% of its supply, but this source has been impacted by new limitations intended to protect fish and the environment. Along with an aggressive and successful water conservation program, NMWD has been proactively developing recycled water for landscape irrigation as another source of water. In 2011, NMWD began advertising a series of recycled water projects for its North and South Service Areas to be completed by the end of 2012. The Novato Recycled Water Project, which totals approximately 10 miles of recycled water pipe, is part of a regional conservation effort which includes the Novato Sanitary District and Las Gallinas Valley Sanitary District.
Two recently contracted projects utilized Fusible PVC® pipe installed via horizontal directional drilling (HDD), instead of conventional open-cut methods. The first project was installed by Ghilotti Construction and consisted of approximately 5,000 LF of 8-inch distribution main. The second project consisted of more than 6,000 LF of 12-inch distribution main installed by Ranger Pipelines. As part of Ranger's project, there was a 700 foot S.M.A.R.T Train crossing for which an 18-inch Fusible PVC® casing was used to house the 12-inch Fusible PVC® carrier pipe. The S.M.A.R.T. Train HDD crossing was designed by Jacobs Engineering of Walnut Creek. Both projects were bid with the option to install the new pipelines via open-cut or HDD. Ultimately, both contractors chose the less disruptive HDD method as the most efficient and competitive.
The use of Fusible PVC® pipe as part of northern California recycled water projects is not novel. In fact, other North Bay providers such as Sonoma County Water Agency/Sonoma County Sanitation District and Napa Sanitation District have also expanded their recycled water systems utilizing Fusible PVC® pipe for trenchless (HDD and jack & bore) and conventional open-cut applications with pipe sizes ranging from 8-inch to 24-inch.
Drew McIntyre, chief engineer with MNWD, stated: "Leaving the option up to the contractor to use either open-cut or horizontal directional drill installation methods worked well for these specified projects."
Brendan Smith, Superintendent for Ranger Pipelines, said: "UGSI's field support, equipment, scheduling, and coordination was excellent. UGSI was very facilitating to work with on the entire 1.4 mile project."
Ghilotti Construction Superintendent Dean Silverlock added: "Fusible PVC® pipe worked great for us on this project. We got great support from UGSI. We also had no leaks on the entire Fusible PVC® pipeline."