Wastewater under Home Plate

by Walter A. Bishop, Jr., Partner; John Carollo Engrs., Walnut Creek, CA,
John S. Fraser, Project Engr.; John Carollo Engrs., Walnut Creek, CA,

Serial Information: Civil Engineering—ASCE, 1992, Vol. 62, Issue 10, Pg. 61-63

Document Type: Feature article


A short, highly sloped piping system and peak flows at the start and end of the day were causing the wastewater treatment plant in Daly City, Calif., to frequently exceed its permit for discharges. Consequently, further development in the San Francisco suburb was prohibited. To lift the ban, the treatment plant had to expand its capacity. There was room next door, but next door happened to be the city's main downtown park, and home to several Bay Area softball teams. Lacking feasible alternatives, the plant, the city and the designers, John Carollo Engineers, Walnut Creek, Calif., decided to build the structure underground, and rebuild the park on top of it. After several years of design and construction, the city now has a 2.8 mgd structure buried underneath the park. Along the way, engineers had to contend with diverting wastewater flow, controlling odors, ensuring worker safety and keeping the structure from floating up on the groundwater table. Fully operational for over a year, the plant expansion has helped mitigate the peaks and eliminate violations, allowing Daly City to continue to grow.

Subject Headings: Wastewater treatment plants | Urban areas | Urban and regional development | Underground structures | Parks | Structural safety | Occupational safety

Services: Buy this book/Buy this article


Return to search