ASTM D8408/D8408M-21 PDF

SIGNIFICANCE AND USE 5.1 There are two primary types of vapor mitigation systems: Active and Passive (Table 1). Active vapor mitigation systems include: Sub-Slab Depressurization (SSD), Sub-Membrane Depressurization (SMD), Sub-Membrane Pressurization, Block-Wall Depressurization, Drain-tile Depressurization, Building Pressurization, Heat-Exchange Systems, and Indoor Air Treatment. Passive vapor mitigation systems include: Passive Venting, Floor Sealants, Vapor Barriers, and Increased Ventilation. Vapor mitigation systems may also consist of a combination of active and passive technologies. 5.2 Development and implementation of a LTM Plan is important for ensuring the long-term protectiveness of the mitigation systems. 5.3 The approach presented in this guide is a practical and streamlined process for establishing long-term monitoring requirements, monitoring time frames, and factors needed to determine when the use of a vapor mitigation system is no longer needed. 5.4 This guide is intended to be used by environmental professionals including: consultants, building managers, local or regional governing or regulatory agencies, that are installing vapor mitigation systems, conducting monitoring of the vapor barriers, or developing LTM Plans for vapor mitigation systems. Vapor mitigation system installation and LTM activities should only be carried out by environmental professionals who are trained in the proper application of vapor mitigation systems and experienced in the monitoring described in this guide, as applicable. Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend... SCOPE 1.1 This guide presents factors to consider when developing Long-Term Monitoring (LTM) Plans for monitoring the performance of both active and passive vapor mitigation systems in buildings. This guide will also assist in developing appropriate performance standards to make sure that vapor mitigation systems remain protective of human health. Active and passive vapor mitigation systems have been used for a number of years on contaminated properties where residual volatile contaminants remain in the ground. This guide discusses a variety of vapor mitigations systems; however, its focus is on the development of long-term monitoring plans for vapor mitigation systems that are designed to remain in place for multiple years. 1.2 A LTM Plan provides clear performance goals for a vapor mitigation system which help to reduce potential confusion and ineffective project management. The LTM Plan also defines performance monitoring time frames to efficiently test the vapor mitigation systems’ effectiveness without unnecessary and costly over-testing. This will also promote consistent monitoring. Vapor mitigation systems are often installed without adequate consideration of the long-term monitoring requirements necessary to make sure that they remain protective of human health for as long as the system remains in place. This guidance addresses the requirements of the LTM Plan to monitor a vapor mitigation system’s continued effectiveness. Installation verification that the vapor mitigation system was installed correctly is typically addressed in the Remedial Design stage of a contaminated Property Management and is not covered in this document. 1.3 LTM Plan limitations, constraints and potential sources of error are discussed in this standard. This guide does not endorse a mitigation system vendor or testing of vapor mitigation systems. However, this guide does provide a reference for the common procedures for testing vapor miti...