Lester J. Berglund Water Treatment Plant Clearwell Replacement

Ardurra supported the City of Poway in planning the replacement of its 10 MG Clearwell, the central treated water storage facility serving the entire city and a critical regulatory component of the Lester J. Berglund Water Treatment Plant. Originally constructed in 1964, the Clearwell consisted of a below-grade hopper bottom basin with a floating cover and a geomembrane liner. The team conducted detailed condition assessments, including material testing of the floating cover and liner, ultrasonic testing of the 42-inch steel effluent pipeline, and coordination with the Division of Drinking Water. Ardurra evaluated full replacement alternatives, including floating cover and liner rehabilitation, circular steel tanks, and prestressed concrete tanks, and analyzed capital and life-cycle costs. The team also designed a temporary bypass system featuring 1,140 feet of 36-inch steel pipeline, a 3,900 gpm pump station, and 2.2 MG of temporary storage tanks.

Key Highlights:

• Evaluated multiple replacement alternatives, including floating cover rehabilitation, circular steel tanks, and prestressed concrete tanks, with capital and life-cycle cost analysis
• Designed a temporary bypass system with 1,140 feet of pipeline, 3,900 gpm pump station, and 2.2 MG storage to maintain uninterrupted service
• Completed planning and design under an accelerated timeline while meeting regulatory requirements and minimizing operational impacts

The project positioned Poway to replace critical 60-year-old infrastructure while maintaining continuous water service to the community and meeting all Division of Drinking Water requirements during bypass operations.