As part of a project involving preliminary design of a seawater RO treatment plant, Carollo re-designed an ocean intake, outfall, and diffuser system. Engineering services, in addition to design included permitting and feasibility assessments.

The intake and outfall system consisted of a horizontally directionally drilled tunnel that extends 2,000 ft into the Pacific Ocean. The tunnel design includes a 28-inch diameter casing that contains 2-inch to 10-inch diameter intake pipes and a 10-inch diameter discharge pipe that carries brine from the seawater RO treatment plant to the diffuser system.

Offshore structures designed by Carollo included an intake structure and the outfall diffuser system.