Nunes Water Treatment Plant Upgrades Project


Coastside County Water District


HDR Inc.

Construction Manager:

Contract Value:


Project Description:

The Nunes Water Treatment Plant is one of two plants that serve the scenic town of Half Moon Bay. The Plant treats 4.5 MGD. This project involves critical upgrades which will allow the plant to keep up with increased demand. Some of the work that is included but not limited to:

Civil Site Improvements including the construction of asphaltic concrete pavement, excavation and regrading of existing hillside to construct a retaining wall and plate settler sedimentation basin. Construction of a soil nail retaining wall with stained concrete finish, construction of an aggregate base access road. Drainage improvements including surface ditches, storm water drains and foundation drains. Site grading improvements, new fire hydrant on the raw water pipe.

Plate Settler Sedimentation Basin. Construction of new concrete plate settler basin, influent and effluent piping, installation of Plate Settler and Sludge Control System.

Filtration System Improvements. Underdrain replacement, filter media replacement, addition of media air scour system including horizontal centrifugal blower. Addition of Filter-to-Waste pumps and piping. Existing filter system valve replacement and addition of new valves. New flowmeters downstream of the filters.

Caustic Soda Bulk Tank System. New Caustic soda chemical storage tank, new skid mounted transfer pump and an emergency shower and eye wash assembly.

Clearwell exterior and interior concrete repair and new elastomeric polyurethane coating.

Project Information:

Status: Current
Category: Sewer Transmission, Water Treatment Plant,
Client Type: County,