Field scale quantification of contaminant mass fluxes and natural attenuation rates using an integral investigation approach

Standard groundwater investigation methods are generally based on regionalised concentration point measurements. To overcome this limitation, an integral investigation approach was applied at a former urban gasworks contaminated with BTEX and PAH compounds. Mass fluxes were quantified at two control planes situated 140 m and 280 m downstream from the contaminant source. Compound specific mass fluxes were measured and effective natural attenuation rates ranging from 4.7E-07 s⁻¹ to 1.6E-06 s⁻¹ were estimated for the target compounds, based on their specific mass flux changes between the control planes.