Title: Soil air project – Parameters responsible for the temporal variations in the soil air content in sand and clay soils contaminated with chlorinated solvents. Appendices 
Resource Type: document --> technical publication --> report 
Country: Denmark 
Language(s): Danish
Year: 2006 
Availability: Environmental project, Miljørapport nr. 1095 
Author 1/Producer: Jørgensen, Torben Højbjerg 
Other Authors/Producers: Glensvig, Dorte; Buck, Christian; Bote, Tage V.; Nilausen, Lena; Mortensen, Peter; Skou, Hans 
Author / Producer Type: Agency, regulator or other governmental or inter-governmental body 
Publisher: The Danish Environmental Protection Agency, Miljøstyrelsen 
Publisher City: Strandgade 29, DK-1405 Copenhagen K, Denmark 
Report / download web link (=direct link): http://www2.mst.dk/common/Udgivramme/Frame.asp?pg=http://www ...  
Format (e.g. PDF): PDF 
Size: (e.g. 20mb) 5.2 
EUGRIS Keyword(s): Contaminated land-->Contaminated land overview
Contaminated land-->Site investigation-->Site investigation overview
Contaminated land-->Soil and groundwater processes-->Soil and groundwater processes overview
Short description: The project (see report nr. 1094 for summary) concerns literature and field studies of the parameters affecting soil air and indoor air in buildings due to underlying soil and groundwater pollution with chlorinated solvents. Field studies at sites with sandy and clay soils have demonstrated large variations in the soil air content especially for clay soils. 
Long description: Results for the field measurements were carried out at three localities are shown (see Report nr. 1094 for summary) ; one with sandy soils and two with clay soils. Fields measurements included outdoor and indoor (sub-slab sampling) subsoil gas probes and outdoor/indoor air measurements. Up to five measurement periods with continuous measurement of trichloroethylene (TCE) and tetrachloroethylene (PCE), radon, differential pressure (above/below floor level) as well as soil, groundwater and meteorological measurements were made. The effect of equipment and pump conditions on pollutant air concentrations was also evaluated. Temporal variations in the soil gas concentration of up to a factor of 2 in sandy soils, but up to 2 orders of magnitude in clay soils were observed. Vapour intrusion to indoor air is affected by many factors and no clear cause–and-effect relationships were identified. Barometric pressure changes and precipitation have significant short-term effects on soil gas concentrations in clay soils. An increase in barometric pressure results in a decrease in soil gas concentrations, whereas a fall results in an increase. Changes in the groundwater levels (often causing a smear zone) can have significant long-term effects. In clay soils, sampling and purging should be carried out at the lowest possible flow; preferably 0.1-0.5 l/min and not more than twice the volume of the probe, but sandy soils are less sensitive. 
Submitted By: Dr Jacqueline Falkenberg WhoDoesWhat?      Last update: 30/01/2007