Formatted Title
The Art of Designing and Implementing Constructable Vapor Intrusion Mitigation Systems for Complex Industrial Projects
Background/Objectives
An acceleration in industrial development activity was seen throughout the COVID-19 pandemic. While many of these sites were in prime infill locations for optimal access to major markets and high populations, they came with an environmental “price tag”, where a vapor intrusion mitigation effort was necessary to protect future tenants, as well as to manage the developer’s long-term liability.
Langan and MTN, Inc. have designed and installed, respectively, millions of square feet of vapor intrusion mitigation systems (VIMS) for industrial warehouse and manufacturing projects across North America. Many of the same questions, concerns, and challenges tend to arise during design development, the contractor bid process, and field implementation. The objective of this presentation is to prepare the audience for those questions and provide means and methods to overcome them. Topics covered will include vapor barrier durability and related installation techniques, concrete placement methods and sequencing, means and methods of vapor barrier protection, along with design considerations for warehouse-specific construction methods, structural details, and end-use.
Approach/Activities
The projects that will be referenced include a commerce center in the Northeast US consisting of two approximately 1MM square foot speculative buildings and a distribution center in the Southeast US consisting of four warehouses ranging from 70,000 square feet up to 150,000 square feet. These case studies will take a closer look at vapor intrusion barrier only and vapor intrusion barrier plus passive venting system approaches, as well as the sequencing and means and methods of construction and how such factors impacted the designed mitigation cross-section/material layering and installation methodology.
Results/Lessons Learned
The design and the installation of VIMS are not independent of one another. As such, coordination between the designer, installer, general contractor, and other subcontractors must happen early and frequently. A discussion on these coordination efforts, as well as best practices, as it relates to team coordination, will be a focus of this presentation. We will also highlight in-field quality assurance and quality control measures necessary to install the VIMS, as designed. And finally, we will take a high-level look at the cost benefit analysis of different vapor mitigation approaches, in the context of the overall development strategy.