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. An impervious membrane must comprise materials approved by the LADBS.
Wing Dam or Wing Dike A “Wing Dam” or “Wing Dike” refers to a dam that intentionally retains a fraction of the width of a flowing water source. Unlike a conventional dam, a wind dam aims to divert the path of water flow. Additionally, a wing dike can control the velocity of water flow. For…
Vent Riser in Methane Mitigation Vent Riser in Methane Mitigation: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a vent riser is a cast iron or ABS pipe that runs through the building walls (vertically). A vent riser is part of a methane mitigation system and has…
Methane Soil Gas Methane Soil Gas: In geology, methane soil gas refers to the confinement of CH4 within the interstitial pore spaces of subsurface soils. On Earth and potentially on Mars, methane derives from subsurface pockets of biogenic and petrogenic natural gas. To illustrate, accumulations of buried organic matter decay via microbial or thermal degradation….
U-Shaped Kitchen U-Shaped Kitchen: A U-shaped kitchen, or a horseshoe kitchen, is a general kitchen plan layout with counters, walls, and cabinets that generally form a square-like or rectangular-like shape of the letter “u.” In the State of California (and other states with similar building code standards), U-shaped kitchens must have a minimum of 60-inches…
Sedimentary Rock Definition In geology, the term “Sedimentary Rock” refers to the classification of rock that is the result of the gradual consolidation and deposition of loose particles of other rock classifications (igneous or metamorphic). Alternatively, sedimentary rocks can also form by the accumulation and precipitation of other natural chemical solutions in a depositional environment….
Maximum Soil Screening Levels (MSLs) Maximum Soil Screening Levels (MSLs): MSLs are a list of risk-based hydrocarbon concentrations for soil pollution evaluations, that is developed by the California Regional Water Quality Control Board. These screening levels are based on the Leaking Underground Fuel Tanks (LUFT) Manual, for cleaning up soil contamination from leaking USTs. However, MSLs…
