Vapor Intrusion
Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.
Vapor Intrusion occurs when harmful soil contamination changes phase from liquid to vapor underground and moves upward through geologic layers and building foundations, accumulating within indoor air.
Liquid Limit (LL) “Liquid Limit (LL)” in the field of geological engineering, refers to the upper limit of the “plastic state.” This is a separation of the plastic phase and viscous liquid phase when measuring soil consistency. Mathematically, it is the water content (basing on the percent of dry weight), at which two sections of…
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…
Phase 2 Environmental Screening Level Phase 2 Environmental Screening Level Numbers are comparative concentrations of chemicals in soil or soil-gas, which represent a threshold for human health concern. In a Phase 2 Environmental Site Assessment, these numbers are tools to compare directly with the contaminant detection on site. As a result, a practical risk assessment…
Metamorphic Rock Definition In the field of geology, the term “Metamorphic Rock” refers to a rock classification that is the result of the alteration of prior existing sedimentary rocks or igneous rocks. The alteration process is “metamorphosis, and can take place by various methods and environments. The metamorphosis process produces specific metamorphic rocks, on the…
Volatile Organic Compounds (VOCs) Volatile Organic Compounds (VOCs): Volatile Organic Compounds are toxic organic chemicals with higher tendencies to change from liquid to vapor phase under typical earth pressures and temperatures, and usually have little-to-no water solubility characteristics. VOCs are commonly found within hydrocarbon-based fuel additives, industrial solvents, refrigerants, hydraulic fluids, degreasers, and more. These…
Runoff (R) The term “Runoff” (R) in hydrogeology and geology refers to the part of rainfall which accumulates on the ground surface and naturally forms into flowing streams.