Design Methane Concentration: In accordance with the Los Angeles Department of Building and Safety Methane Code, Ordinance Number 175790, a Design Methane Concentration is the highest recorded concentration of methane soil gas detected during the course of methane testing on a property. The Design Methane Concentration is what defines the level of methane mitigation applicable to a subject site.
Hydraulic Head Hydrualic Head: In the field of hydrogeology, hydrualic Head is a measure of the potential energy of a fluid at any given point in a hydraulic system. It explains the potential energy driving fluid flow by summing the elevation of the fluid and the pressure it exerts.
What is a Concrete Slab and Buttress Dam? A Concrete Slab and Buttress Dam is a freshwater-retaining structure comprising reinforced concrete slabs that are supported in-place by buttresses. The foundation of a Concrete Slab and Buttress Dam receives a large load. Thus, the foundation must be structurally sound, impervious, and competent. The alternative types of dams…
Confined Aquifer Confined Aquifer: In the hydrogeology branch of geology, a confined aquifer is an aquifer that is overlain (and underlain) by a layer of low permeability, such as clay, shale, or silty clay. In fact, the two confining layers contain the storage and flow of groundwater, such that the aquifer maintains hydraulic pressure (or…
Stratosphere Stratosphere: The stratosphere of a terrestrial planet is the second-lowest member of the atmosphere. On Earth, the stratosphere starts atop the troposphere at approximately 10 kilometers above mean sea level, and terminates roughly 50 kilometers above mean sea level. In fact, geologists understand that the Earth’s ozone layer exists within the stratosphere, which absorbs…
Well Graded Soil Well Graded: In the soil classification process of geology, well graded soil represents a sedimentary soil sample that fully displays all of the possible grain sizes for that soil classification, in accordance with the Unified Soil Classification System (USCS). For example, a well graded sand (SW) comprises fine, medium, and coarse grains…
Impervious Membrane in Methane Mitigation Impervious Membrane: In accordance with the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, an impervious membrane is a continuous methane gas barrier. It is a crucial part of the methane mitigation process and underlies a building to impede the vapor intrusion of methane soil gas….
