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Water/Environment, Sustainability - Olympic Well Field Restoration and Arcadia Water Treatment Plant Expansion

Photo by Nathan Padilla Bowen

October 26, 2026

Olympic Well Field Restoration and Arcadia Water Treatment Plant Expansion

Santa Monica, Calif.

EXCELLENCE IN SUSTAINABILITY and Award of Merit, Water/Environment

Submitted by: Walsh Construction Co. II LLC

Owner: City of Santa Monica

Lead Design Firm: Brown and Caldwell

General Contractor: Walsh Construction Co. II

FRRO Technology: ROTEC

UV & Advanced Oxidation: Trojan Technologies

A combination of restoring groundwater and improving treatment efficiencies will allow the city of Santa Monica to draw up to 70% of its drinking water locally as part of what the project team describes as the world’s first municipal-scale retrofit of an operating conventional reverse osmosis system with flow-reversal technology.

Completed in August 2025, this $77.5-million project added two groundwater…