- ENGINEERING INFO
- CASE STUDIES
Several communities south of Reno, Nevada have been struggling with water quality and supply issues for some time. Water providers in Carson City, Lyon County, Indian Hills, and Douglas County have been seeking long-term water supplies, while also dealing with arsenic and uranium contamination of existing supply sources. Carson City, for example, with a population of approximately 55,000 people and a peak summer time demand of approximately 25 MGD, obtains the majority of its water from 35 wells located throughout the City; eight of which are impacted by high uranium levels and seven of which have high arsenic levels. While Carson City completed the construction of its first arsenic treatment facility several years ago, the new facility did not address uranium contamination or resolve the need to obtain long-term water supplies to meet increasing demand.
Understanding that these issues represented a regional challenge with impacts beyond a single community, area water providers sought a regional solution. Ultimately, an arrangement was concluded that will use surplus water rights owned by Minden, Nevada to provide a long-term supply of clean water to Carson City, Lyon County, Indian Hill, and Douglas County.
This regional water system project resulted in interconnection of the Minden water system, the North Douglas County water system, the Indian Hills General Improvement water system, the Carson City water system, and the Lyon County (Dayton) water system. When completed, Minden will supply up to 12,000 gpm of water to the region. The regional project will enable Carson City to forgo construction of a uranium-specific water treatment facility that would have cost $40-$50 million to build, plus another $1.4 million per year in operation and disposal costs. Moreover, the project solved Carson City's long-term supply concerns.
Extending from Carson City in the north to Minden in the south, ten projects were bid and constructed with pipes sizes ranging from 4-inch to 36-inch. While the majority of the pipelines were installed using conventional open-cut methods, several areas required trenchless installation methods such as jack-and-bore and horizontal directional drilling (HDD). Trenchless installations were installed under the Carson River, sensitive wetlands, and Nevada Department of Transportation (NDOT) right-of-ways such as Interstate 395.
Fusible PVC® pipe was used for specified restrained-joint sections of the pipelines in place of conventional bell-and-spigot pipe with traditional bell restraints, providing a more efficient, lower-cost installation method providing a more efficient, lower-cost installation method by removing labor-intensive metallic bell restrainers from the system. Removing metallic materials in areas with known corrosive soil conditions is always beneficial to the owners' long-term maintenance budgets. Additionally, environmentally sensitive areas identified by the Nevada Department of Environmental Protection (NDEP) were easily navigated using Fusible PVC® pipe, including areas where the new water line crossed sanitary sewers (gravity and force mains), reclaim water lines, and storm drains.
Overall, four utility owners awarded ten separate projects to eight different contractors. All of the projects built with bell-and-spigot PVC pipe incorporated Fusible PVC® pipe for the open-cut restrained pipe sections and NDEP-designated areas. Two jack-and-bore crossings under I-395 (Minden and Indian Hills GID) and six HDD crossings (Carson City, Indian Hills GID and Douglas County) utilized Fusible PVC® pipe as 4-inch conduit pipe, 18-inch to 30-inch carrier pipe, and 36-inch casing pipe. More than 45,000 LF of 4-inch through 36-inch Fusible PVC® pipe was installed via open-cut and trenchless installation methods for fiber optic conduit, potable water carrier pipe, and casing pipe required for NDOT right-of-way crossings.
Tim Russell, Minden's engineer, stated: "All our PVC projects utilized Fusible PVC® pipe for the restrained sections, jack-and-bore, and HDD crossings. Fusible PVC® pipe provides an economical offering for the owner resulting in real bid-day savings, while taking long-term metallic maintenance issues off the table. We've been using Fusible PVC® pipe since 2007. It's a "great tool" where appropriate."
Dave Rausch, HDR inspector for Carson City, explained: "This material provides a fast, easy, and economical way to make all the NDEP crossings on these projects."
Tony Autino of A&K Earthmovers added: "We have worked with Underground Solutions in Carson City, Fernley, and Lovelock, NV. UGSI provides a great service and stands behind its products. We'll definitely work with them in the future."
Rick Landino, owner of Silverstate Boring, noted: "We've worked with UGSI on more than ten projects, including Douglas County, Carson City, Indian Hills, and Minden. We've installed their pipe via jack-and-bore and HDD. These guys do a great job and really know their business. UGSI is a class act."