Second Corridor Pipeline (36", 30", 12" and 8")

• Owner: Walnut Valley Water District

Walnut Valley Water District supplies potable water to more than 113,000 residents and businesses in six southern California communities. The service area includes 17,900 acres of land, 26,500 connections, 370 miles of pipelines, 16 pump stations, and 29 storage reservoirs.

As part of potable water distribution system expansion plan, the District decided to construct the Second Corridor pipeline. The main pipeline is 36 inches and 30 inches in diameter and approximately 8,450 feet long. The pipeline is located in Sunset Crossing Road, Valley Blvd., and unpaved areas of City of Diamond Bar, Pomona, and Walnut.

Perliter & Ingalsbe was engaged to provide engineering services for the design and construction management. The project included a wide variety of components, complex design tasks, permitting process, extensive coordination efforts and preparation of many drawings and detailed specifications involving civil, mechanical, structural, and traffic control engineering disciplines.

Major Components and Special Features:

• Pipeline route through three cities, Diamond Bar, Pomona, and Walnut
• Approximately 4,500 feet of 36" and 2,700 feet of 30" welded steel pressurized pipelines and fittings
• Approximately 1,250 feet of 12" and 8" ductile iron pipe and fittings
• Pipe appurtenances including blow-offs, air vacuum and air release valves
• In-line butterfly, gate and ball valves, 8" through 36"
• Buried concrete vaults
• Concrete channel crossing (San Jose creek crossing)
• Railroad crossing

• Three 60" Jacked steel casing installations for trenchless pipe installations
• Pipe cathodic protection and electrolysis test stations
• Interconnections with existing mains
• Busy streets with heavy traffic and complex traffic controls
• Utility congestion
• Asphalt repair and site improvements
• Permitting from numerous agencies