Sanitary Sewer Rehabilitation, Phase 7, City of Piedmont

EKI provides design, bid support, and construction support services to replace and rehabilitate approximately 23,000 linear feet (LF) of aging sanitary sewer pipeline as a part of Phase 7 of the City of Piedmont’s Sanitary Sewer Rehabilitation Project. Infiltration and inflow are the chief issues motivating the improvement of these sections of sanitary sewer line. This project’s specific goals are the result of a Consent Decree with the United States Environmental Protection Agency, the State of California, and six other East Bay sewer agencies to reduce inflow and infiltration and sewer system overflows.

The Project involves replacements and/or rehabilitation of 6- to 16-inch vitrified clay pipe (VCP) and associated lower sewer laterals that are within the City right-of-way or easements. Associated manholes (172) are also to be replaced or rehabilitated utilizing cementitious and epoxy coatings, and cleanouts/lampholes are to be similarly improved. Due to very limited access along many of the alignments (particularly those in easements), EKI is prioritizing the use of trenchless replacement and rehabilitation methods, including pipebursting and cured-in-place pipe (CIPP) lining. However, a detailed constructability review at each stage of design is part of EKI’s scope to review access conditions, existing pipe materials, and potential conflicts with other utilities. Generally, the existing pipes are being replaced with high-density polyethylene (HDPE) wherever feasible.

Outcome

EKI continues to assist the City by preparing an application for a State Revolving Fund (SRF) loan through the State Water Resources Control Board (SWRCB) to fund this project. The project scope is split into two phases as it depends on the extent of the secured funding, the estimates prepared during the 75% design phase, and the actual pricing from bidding contractors. Since the construction of the project is dependent on obtaining funding, EKI is prioritizing initial design (35% design) and preparation of the California Environmental Quality Act (CEQA) documentation to support the SRF loan application.