Abs: Building control technologies are typically required at VI sites (in both existing and new buildings)until long-term, site-wide remedies reduce soil and groundwater concentrations to acceptable levels. The following sections discuss various VI building control technologies, factors affecting technology selection, and common design and installation issues. Vapor control for VOCs can include environmental remediation, building … Continue reading
Light Non-Aqueous Phase Liquid (LNAPL) Management is the process of LNAPL site assessment, monitoring, LNAPL Conceptual Site Model development, identification and validation of relevant LNAPL concerns, and the possible application of remediation technologies. The presence of LNAPL can create challenges at any site. In the subsurface, LNAPL can be difficult to assess or recover … Continue reading
Light, nonaqueous-phase liquid (LNAPL) management (LNAPL assessment and remediation) presents some of the greatest corrective action and cleanup compliance challenges to petroleum manufacturing, storage, and handling facilities such as refineries, bulk product terminals, gas stations, airports, and military bases The management of LNAPL requires to first identify the specific LNAPL composition and saturation concerns the … Continue reading
The presence of LNAPL and the characterization of LNAPL in the subsurface is often determined primarily by the measurement and observation of LNAPL in monitoring wells. It is noted, however, that the relative measure of apparent thickness of LNAPL in a well, while indicative of LNAPL presence, has been shown to be a poor … Continue reading
Abs: This section is to provide introduction on technical tools used for LNAPL site characterization The delineation of contamination is contingent on a number of factors. It is important for investigators to understand the extent of LNAPL in a timely manner. Conducting this activity should include upfront planning for, and obtaining access to, locations to … Continue reading
The LNAPL Conceptual Site Model (LCSM) is the body of information describing aspects of the LNAPL and site setting necessary to satisfy the LNAPL remedial objectives. The LCSM is similar to a conceptual site model, which includes the source, pathway, and receptors, but the emphasis in the LCSM is on the source component (i.e., … Continue reading
To begin proper management of an LNAPL site, one must first determine the problems or concerns that the LNAPL poses at the site. A complete site characterization and LCSM will help to identify these concerns. Once the concerns are identified, appropriate “LNAPL remedial objectives” are set to eliminate the LNAPL concerns at … Continue reading
Once the remedial action is implemented, monitoring is required to assess the protectiveness and effectiveness of the chosen interim remedial measures (IRM). The type and frequency of monitoring should be based on the CSM developed for the site which identifies the LNAPL type, source and distribution, site specific receptor issues, hydrogeologic influences on LNAPL behavior … Continue reading
Sites contaminated by chlorinated solvents present a remediation challenge. Chlorinated solvents are among the most difficult groundwater contaminants to remediate, especially at sites with dense, non-aqueous-phase liquid (DNAPL) still present in the source zone. Restoring sites contaminated by chlorinated solvents to regulatory criteria (low parts-per-billion concentrations) within a generation (~20 years) is difficult. Site managers … Continue reading
Type of DNAPL and DNAPL Properties Common DNAPL compounds include materials that have been or are still widely used in industrial and commercial processes, such as the following: chlorinated solvents coal tar creosote heavy petroleum—for example, No. 6 fuel oil products polychlorinated biphenyls (PCBs) pesticides DNAPLs are denser than water, with limited and varying solubility … Continue reading
