Learning Objectives This is an advanced level course. After completing this course, mental health professionals will be able to:
They are fundamental to understanding the logic used in the development of the tools and key to appropriate application of this guidance. The training courses are available online www. Unfortunately, misconceptions derived from our early, less-informed understanding of LNAPL releases are frequently encountered.
Table outlines common misconceptions relating to LNAPL releases and the associated current understanding and key concepts which are discussed in detail in referenced sections of the document.
LNAPL floats on the water table or capillary fringe like a pancake and does not penetrate below the water table Section 3. Typically, water is the wetting fluid in the saturated zone, in direct contact with the soil, and occupies the smaller pores. LNAPL must displace the water and gases within a pore space before it can migrate.
For this to occur, it must have a driving head and overcome the capillary pressure exerted by the water in the pore. Due to the dependence of in-well LNAPL thickness on geology and variable groundwater hydraulics, it should not generally be used as a sole metric for recoverability and indication of migration.
LNAPL cannot be completely removed from soil by hydraulic recovery due to mechanical limitations in subsurface soils. The lowest saturation theoretically attainable by hydraulic recovery is residual saturation, and that is rarely achieved.
LNAPL is considered migrating when it is observed to expand into previously unimpacted locations over time i.
LNAPL bodies associated with a terminated or finite source i. LNAPL is mobile when it is present at a saturation greater than residual.
Mobile LNAPL is potentially hydraulically recoverable, but recoverability depends on various physical factors. Residual LNAPL saturation is different for the saturated and unsaturated zones due to the variable presence of other fluids such as water and gases.
Typically, unsaturated vadose zone residual saturation is generally lower. Water table fluctuations e. Therefore, rarely does hydraulic recovery reduce dissolved phase concentrations. Since LNAPL transmissivity is related to all key variables see above that can affect recoverability, it is a better metric than the conventionally used metric of in-well LNAPL thickness.
Saturation reduction technologies e. Composition change technologies e.
When the LNAPL body reaches this state, the LNAPL body has stabilized in extent, and will not typically expand further unless additional releases or significant subsurface hydraulic changes occur.
Section 4 of this document discusses the development of an LCSM that incorporates a release history and summary of processes that create the observed LNAPL distribution in the subsurface. The volume of aquifer occupied by an LNAPL body is not comprised of a single fluid phase, but rather of multiple fluids and soil in proportions that will vary throughout.
Generally speaking, the spatial extent occupied by an LNAPL body is predominantly comprised of water, followed by a lesser amount of LNAPL, with the smallest fraction of the pore space occupied by gas.A few key factors can increase inherent risk.
Environment and external factors: Here are some examples of environment and external factors that can lead to high inherent risk: Rapid change: A business whose inventory becomes obsolete quickly experiences high inherent risk. Facts, figures and findings from application of Toxkit microbiotests are reported in a large number of publications, reports and presentations at scientific symposia and workshops.
A better understanding of how each state can improve election security preparedness can help build urgency for appropriate solutions and arm stakeholders with information to demand increased. A few key factors can increase inherent risk. Environment and external factors: Here are some examples of environment and external factors that can lead to high inherent risk: Rapid change: A business whose inventory becomes obsolete quickly experiences high inherent risk.
Inherent risk is the third major types of audit risk. Considered the most pernicious of the major audit risk components, inherent risk can't be easily avoided through increased auditor training or.
The Performance Audit Manual requires the auditor to perform risk assessment. during the preliminary study. The inherent risk is the risk level before existing controls and/or Key Risk Residual Risk level H-M-L Audit Question Relevance & Interest H-M-L.