Gresham Smith Joins Team to Rehabilitate Interceptor Sewer for Guam Waterworks Authority

January 22, 2019

Gresham Smith announces that it will serve on a team to rehabilitate 45,000 linear feet – over eight miles – of 18- to 42-inch diameter sewer line as part of the Guam Waterworks Authority (GWA) Refurbishment Project in the Northern District. The existing sewer infrastructure, referred to as the Route 3 interceptor sewer, was constructed in the 1970s and is experiencing failures and blockages resulting in ground water infiltration and inflow (I&I).

The Route 3 interceptor conveys wastewater collected in the northern part of Guam, including Andersen Air Force Base, to the Northern District Wastewater Treatment Plant (NDWWTP), for which Gresham Smith is currently designing the expansion. The current state of the interceptor sewer allows extraneous water from I&I to compromise the treatment capacity of the NDWWTP. This project will reduce flows to NDWWTP to help optimize performance.

“This project is critical to help restore structural integrity in order to protect Guam’s groundwater supply, particularly the Northern Guam Lens Aquifer which supplies the majority of Guam’s drinking water,” commented Ken Baker, senior vice president, Gresham Smith “We are pleased to be working with GWA and the team to help rehabilitate the wastewater infrastructure on the island.”

Gresham Smith will provide design and post design services including project management, CCTV review, preliminary engineering and final design for cured-in-place-pipe (CIPP) and manhole rehabilitation, drawings plans and specifications, permitting of CIPP design and other engineering services. The firm will also leverage expertise in geographic information systems (GIS) to map the sewer system and to provide GWA with a foundation to build a comprehensive database for their sewer system.

The firm is a sub-consultant to JV Core Tech-Hawaiian Dredging Construction Company (CT-HD) and a local engineering firm, Duenas, Camacho and Associates (DCA). The project team was chosen based on its proven track record with sewer rehabilitation projects and ongoing work with GWA. The project will be delivered using a progressive design-build approach.