Pi (Oil Spill) Services Ltd

In the context of the oil spill industry

Absorbents (oleophillic)	Materials utilised for the preferential collection of free phase fuel oils. Available in varying media adapted to intercept and collect oil from specific environments, e.g. streams, drains, hardstanding etc.

Activated carbon	Highly porous carbon which is an extremely effective adsorbent for fuel oil hydrocarbons, amongst other substance types. Uses include purifying water and air sampling.

Attenuation	General term for a reduction in concentration of a substance, e.g. a contaminant reduced by dispersion or biological processes.

Auger	A device used when soil boring for samples, or well installation purposes. Augers can be hand or mechanically driven.

Bio-remediation	Restoration of contaminated water or land utilising natural or induced biological processes. Contaminant degradation might be enhanced by oxygenation, addition of bacteria and/or nutrients and increasing contaminant exposure, amongst other things.

Controlled waters	Defined by the Water Resources Act 1991, Section 104, to include inland fresh waters, groundwaters, estuaries and coastal waters within a three mile limit of the shore.

Diesel	A colourless fuel very similar to gasoil comprising a mixture of compounds (predominantly hydrocarbons), distilled from crude oil and used in road vehicles. Also known as DERV (Diesel Engined Road Vehicle) fuel.

Dissolved phase	Describes the existence of substances (e.g. components of a fuel oil such as hydrocarbons) in a dissolved state, typically in an aquatic environment following weathering.

Emulsion	Fine dispersion of two immiscible* liquids through one another, brought about by varying processes including pumping and weathering.
	* Immiscible - describes fluids that will not conventionally mix, such as oil and water.

Free phase	Describes the existence of fuel oils in their original state or at high saturation in soil or water.

Gasoil	A fuel very similar to diesel comprising a mixture of compounds (predominantly hydrocarbons), distilled from crude oil, dyed red and used in industrial plant, vehicles and boilers.

Hydrocarbons	Compounds that typically contain only carbon and hydrogen, although some may contain trace quantities of oxygen, nitrogen, sulphur and other elements. They are prominent in fossil fuel oils and the most common hydrocarbon groups found in these fuels are paraffins, napthenes and benzene type compounds.

Hydrocarbon chains	Carbon atoms in hydrocarbons are arranged in open ended chains or closed rings to form molecules. The hydrocarbon molecule size is readily distinguished by the number of these carbons (e.g. C10, C11, etc.) and the magnitude of this provides an indication of the properties of a given compound. The range of sizes identified by analysis within the blend of a fuel oil, can be central to a more precise speciation of the particular substance.

Interceptor	A device permanently installed in the line of an effluent flow to remove free phase oil from water. Floating oil is typically separated from the water by means of a series of baffles.

Interface meter	A device used to simultaneously measure groundwater depth and the overlying oil thickness (if applicable), e.g. down a monitoring well.

Kerosene	A colourless fuel predominantly comprising hydrocarbons, distilled from crude oil and used in domestic oil-fired boilers or in adapted forms as jet fuel.

Migration	Describes the process and route of transport of a contaminant, from one place to another.

Monitoring well	An installation featuring the setting of tubular perforated screen into a soil bore, to depths below groundwater level, so as to provide ready access to the same for sampling or depth monitoring purposes.

Pathway	A specific route along which a contaminant moves through the environment.

Perched groundwater	An accumulation of water, whose dispersal is inhibited by a low permeability soil or rock layer and which is suspended above the main water table.

PID	Photo-ionisation detector. A device used to detect the presence and approximate concentration of airborne "volatile organic compounds" (VOCs).

Plume	Describes the area encapsulating the significant extents of dispersal of a contaminant such as a fuel oil, e.g. in free phase form across a body of water; at high saturation through soil; in high adsorbed concentration through soil, etc.

Receptor	An entity (e.g. controlled water, structure, etc.) which has been, or could potentially be impacted by a contaminant

Separator	As per "interceptor" but generally refers to mobile units used to respond to pollution incidents.

Sump	An excavation developed into the subsurface, generally within the oil plume, for the purposes of product recovery or treatment.

Surfactants	Substances which can reduce liquid surface tension and thus, in a spill remediation scenario, can increase contaminating oil's exposure by enhancing emulsification processes. Bio-surfactants can further contribute to increasing degradation rates by introducing nutrients to aid bacterial activity.

TPH	Total petroleum hydrocarbons. Since the term typically embraces the hydrocarbon ranges C8 to C35, it is in strict terms a misnomer as the very light hydrocarbon fractions (e.g. below C8) are not included.

Trial pit	An exploratory excavation developed into the subsurface aimed at exposing the soil profile and/or the contaminant.

VOCs	Volatile organic compounds. Organic compounds which evaporate readily and therefore contribute to air contamination - typically the lighter fractions of fuel oils. VOCs include hydrocarbons as well as other compounds of carbon and hydrogen containing also elements such as oxygen, nitrogen or chlorine.

Volatilisation	The evaporation of volatile compounds, i.e. the process by which the liquid phase changes state to the gaseous phase.

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