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…

Geology Geology: Geology is a field of science relating to the earth, including but not limited to the earth’s resources, physical processes, chemical properties, history, and future. Additionally, the science of geology includes the study of other terrestrial planets, such as Mercury, Venus, or Mars. Branches of Geology There are numerous branches of geology that…

Effective Stress (σ’) “Effective Stress” (σ’) is a geotechnical engineering term. Effective Stress is a function of “total stress,” and is due to the solid particles of soil. Effective stress represents an excess of stress above pore-water pressure (or neutral stress). Effective Stress Formula Effective Stress = Total Stress – Pore-Water Pressure.

Silicates Definition In the fields of geology and mineralogy, the term “silicates” refers to compounds whose crystal structure contains SiO4 tetrahedra. Silicates are either isolated or joined to form groups, rings, single or double chains, sheets, or three-dimensional frameworks.

Mineraloid Definition The term “mineraloid” refers to a natural earth substance that appears to be similar to a genuine mineral, although lacks any form of internal structure and crystal form. Nonetheless, a mineraloid does comprise true minerals within it. For instance, Fire Opal and Blue Opal are not minerals because they are amorphous (do not…

Surface-Wave Magnitude “Surface-Wave Magnitude” is the magnitude of an earthquake that scientists estimate using measurements of the amplitude of surface waves.