Title: A Practical Guide to Assessing DNAPL Releases in the Subsurface (Technical Bulletin 11) 
Resource Type: document --> technical publication --> methodology description 
Country: United Kingdom 
Year: 2004 
Author 1/Producer: CL:AIRE 
Other Authors/Producers: Laharne, Steve (University Greenwich), Weathall, Gary (BGS), Learner, David (University Sheffield), Smith, Jonathan (Environment Agency) 
Author / Producer Type: Professional / trade / industry associations, institutes or networks 
Publisher: CL:AIRE 
Report / download web link (=direct link): http://www.claire.co.uk/bulletin.php  
Format (e.g. PDF): PDF 
Size: (e.g. 20mb) 547 
EUGRIS Keyword(s): Contaminated land-->Contaminants-->BTEX
Contaminated land-->Contaminants-->Chlorinated aliphatics
Contaminated land-->Contaminants-->PAH
Contaminated land-->Risk assessment-->Exposure pathways
Contaminated land-->Risk assessment-->Models
Contaminated land-->Risk assessment-->Sources
Contaminated land-->Site investigation-->Conceptual site model
Groundwater protection-->Monitoring-->Monitoring overview
 
Short description: This bulletin provides a summary of a recently published Environment Agency (EA) report entitled, 'An illustrated handbook of DNAPL transport and fate in the subsurface'. The purpose of the bulletin is to describe how the report came about and to introduce some of the terms, concepts, problems and solutions relating to DNAPL contamination in the UK which are addressed in more detail in the EA report. 
Long description: Dense non-aqueous phase liquids (DNAPLs) are heavier-than-water organic liquids that have been widely used in industry from the early 1900s to the present. DNAPLs are only slightly soluble in water, and therefore exist in the subsurface as a separate fluid phase, immiscible with both water and air. Common types of DNAPLs include wood treating oils such as creosote, transformer and insulating oils containing polychlorinated biphenyls (PCBs), coal tar and a variety of chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE). Unlike light non-aqueous phase liquids (LNAPLs) such as petrol and heating oil, DNAPLs have the ability to migrate to significant depths below the water table where they slowly dissolve into flowing groundwater, giving rise to aqueous phase plumes. A release of DNAPL at the ground surface can therefore lead to long-term contamination of both the unsaturated and saturated zones at a site. 
Link to Organisation(s): CL:AIRE (Contaminated Land: Applications in the Real Environments)
 
Submitted By: Mr John Henstock WhoDoesWhat?      Last update: 15/02/2007