PVC sheet piling for cutoff and containment barriers PVC sheet pile effectiveness in cutoff applications 4a FIGURES 4a and 4b Bolsa Chica PVC sheet pile cutoff wall alignment 4b The U.S. Army Corps of Engineers ( U S AC E ) re c e nt ly publ ishe d t he Interim Poly Vinyl Chloride (PVC) Sheet Pile Guidance document, which provides guidance on the applications of PVC sheet piling as well as the important specification requirements. This document lists hydraulic cutoff barriers as an application for PVC sheet pile. In addition, the USACE recommends that all virgin PVC used shall have a minimum cell classification of 1-42443-33, in accordance with ASTM D4216, and that the manufacturer provide a certificate of analysis attesting to this along with the product warranty (USACE 2017). The effectiveness of PVC sheet piling as a barrier can best be demonstrated by reviewing the real-world results from case studies. The following case studies were chosen primarily because of their age, postconstruction monitoring of the effectiveness and proven continued performance. Many other case studies are available. However, in many cases postconstruction monitoring data is not always readily available. Anecdotal evidence would suggest that the effectiveness of PVC sheet piles for cutoff applications is becoming more widely accepted by the engineering community as usage continues to increase. Bolsa Chica The Bolsa Chica Lowlands Restoration Project is the largest wetland restoration in Southern California history. The project created or restored more than 600 acres (243 ha) of marine and wetland habitat and was built as required mitigation for the expansion of the Ports of Long Beach and Los Angeles. Restoring the wetlands involved reconnecting the 32 Geosynthetics | August September 2020 0820GS_p28-37.indd 32 7/23/20 8:44 AM