Twin Oaks Treatment Plant

The Problem

Population growth and federal water quality mandates are necessitating water providers across the country invest in new water treatment facilities. Shrinking water supplies are also demanding systems reevaluate how their “dirty” water is utilized. This is particularly true in the Southwest, where water scarcity and growth are nothing new. Northwest Pipe Company’s engineered steel water pipe systems repeatedly help communities across the U.S. build water treatment facilities.

In nearby San Diego County, water supply is scarce and demands are high. Northwest Pipe joined CH2M Hill Constructors on the Design/Build/Operate (DBO) Twin Oaks Water Treatment Plant. The new facility, just off of an existing aqueduct, will provide up to an additional 220,000 households with finished water. As a DBO contract, the project involved a high level of mid-construction design decisions. To keep the project running smoothly, Northwest Pipe representatives from sales, project management, manufacturing, engineering, and field operations met weekly with CH2M Hill for progress updates. This kept communication channels open so deliveries and design could be adjusted to meet all developing situational changes.

Water scarcity is not just limited to California. Communities in New Mexico also struggle to provide their residents with adequate supplies. In Albuquerque, the San Juan-Chama Project is underway to bring 110,000 acre-feet per year from the upper tributaries of the San Juan River, under the continental divide and into the Rio Grande. This water was allocated in 2006 to New Mexico as part of the multi-state agreement reached between western states vying for Colorado River water rights. Like the Orange County project, Northwest Pipe worked closely with the contractor, PCL Civil Constructors, to provide the entire scope of pipe needed for this important component to the San Juan-Chama Project.

These projects offer a sampling of the quality and service provided by Northwest Pipe Company. Large diameter, highly engineered steel water pipe systems save time and money by reducing field fit-ups and other issues inherent to commodity pipe materials. Northwest Pipe’s close coordination with the contractors allows for just-in-time shipments to space constrained jobsites, reducing costs and inconveniences to project neighbors.

How we solved it →

Rancho Penasquitos Pipeline Relining

The Problem

The San Diego County Water Authority (SDCWA) faced a daunting task when the pre-stressed concrete cylinder pipe (PCCP) in their system began to fail. The strength of PCCP comes from steel wire wrapped around a steel shell. A coating of Portland cement gives the pipe stability as well as corrosion protection. However, if the cement cracks and corrosion attacks the wire, the pipe can fail catastrophically. Many such failures have occurred over the last few decades. As a result, agencies are aggressively replacing PCCP with a more reliable material. For San Diego County, solving the problem of their 50-plus miles of failing PCCP is a massive task.

How we solved it →

Point of the Mountain Aqueduct

The Problem

Working with CH2M Hill, the Metropolitan Water District of Salt Lake City & Sandy (MWDSLCS) is developing a water supply system to bring up to 70 million gallons a day of water to customers in Draper and Sandy Cities. The Point of the Mountain Aqueduct (POMA) will transport the water to a new treatment plant to ensure supply exists for the growing Salt Lake Valley. The pipeline will also provide redundancy to the MWDSLCS system in the event another portion of the system needs to be taken out of service for repair.

How we solved it →

Nevada Project Intake 1

The Problem

Southern Nevada Water Authority (SNWA) diversions from Lake Mead were in jeopardy due to drought conditions in the West, causing historically low water levels. The Authority was concerned that their intake structure might surface if water levels continued to drop.

The first diversions of Lake Mead water occurred in 1934 when pumping to Boulder City began from a plant inside Hoover Dam. In April, 1942, water was diverted from Lake Mead for war effort plants in Henderson, Nevada. With declining groundwater levels, large diversions for the Las Vegas Valley began in January, 1984, through the Southern Nevada Water Project diversion at Saddle Island. In 1991, the Southern Nevada Water Authority was established to address regional water issues. The Water Authority is committed to managing the region’s water resources and developing solutions to ensure adequate water supplies for the future. The Southern Nevada Water Systems (SNWS), which began operations in 1971, comprises the Water Authority’s system to pump, treat, and deliver water from Lake Mead. SNWS was officially transferred from the federal government to the Authority in 2001.

How we solved it →

Green Bay Raw Water Pipeline

The Problem

The City of Green Bay, Wisconsin is one of many municipalities that recently made a major upgrade to their primary water supply pipelines. The City’s existing Pre-stressed Concrete Cylinder Pipe (PCCP) line that connects the city’s intake structure on the shores of Lake Michigan to their water treatment facility is beginning to show its age and lack of reliability.

This PCCP pipeline and the City’s auxiliary well fields were not able to support Green Bay’s peak water demands and growing customer base. Green Bay needed to support their water supply sources by building a parallel transmission line to the failing PCCP line to provide them a more reliable access to their primary water source.

How we solved it →

Elgin Area Primary Water Supply Project

The Problem

The original Elgin Area primary transmission pipeline was constructed in 1966 and consists of more than 14.7 kilometers (48,000 LF) of 750mm (30”) concrete pressure pipe from the water treatment plant in the Municipality of Central Elgin to a terminal reservoir just east of the city of St. Thomas located in Central Elgin. The 14,700 meters (48,000 LF) of 900mm (36”) diameter Steel Water Transmission Pipe with a Cement Mortar Lined (CML) existing Elgin Middlesex Booster Pumping Station and Reservoir valve house. The Elgin Area Primary Water Supply System services the cities of St. Thomas, London, Aylmer, Bayham, Central Elgin, Port Burwell, Southwold and other surrounding areas, for a total population of 112,000 people.

How we solved it →

Illinois DOT Rail Road Crossing Project

The Problem

Installing a 50-foot tunnel underneath a rail line, owned by the Peoria & Pekin Union Railroad, to create a new bike path. Shallow space under tracks and over surface slump and sandy soil conditions caused concern. Originally, the Illinois Department of Transportation wanted a box culvert for a walkway, but the project was changed over to specify round casing for a pedestrian tunnel and bike path.

How we solved it →

City of Wichita Water Main Project

The Problem

Completing numerous water main installations, under both highway and railroad locations, in a timely manner. Difficult soil conditions, multiple project phases and multiple contractors created the potential for delays.

How we solved it →