Single Station Methane Gas Detector Single Station Methane Gas Detector: As per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a single station methane gas detector is a device consisting of electrical components that are capable of measuring methane soil gas concentrations indoors, and initiating an alarm. The single…

Anion Anion: In the fields of chemistry and geochemistry, an anion is a negatively charged ion. The oppositely charged ion is a cation.    

Trench Dam Trench Dam: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, a trench dam is part of a methane mitigation system. A trench dam is essentially a subsurface barrier that exists within a furrow or ditch, that is adjacent to the foundation of a building in a…

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…

Aphanitic Definition Aphanitic: In geology, the term aphanitic describes the texture of plutonic or volcanic igneous rocks, with grains that are not visible to the naked eye. In fact, an aphanitic texture is usually the result of faster cooling and solidification of liquid magma.

Unobstructed Opening Definition in Methane Mitigation Unobstructed Opening: Per the Los Angeles Department of Building and Safety (LADBS) Methane Code, Ordinance Number 175790, an unobstructed opening is a permanent clearance or gap in the walls, floors, or ceiling of a structure, to allow for direct fresh airflow. In methane mitigation plan applications, this does not…