Chemical Oxidation and Biostimulation Achieves Significant Plume Reduction with Single Amendment Application

In situ treatment to an active petroleum service station site in the coastal plain of Florida, USA

Type of Site

Active petroleum service station site



Contaminants Treated

Petroleum hydrocarbons


A historical release of gasoline affected a 1,550-square-meter area and a volume of 9,600 cubic meters of a sandy aquifer. A layer (3 centimeter maximum) of LNAPL was present in a 56-square-meter area. Klozur® CR (5384 kg) was applied to the source area (450 square meters) and PermeOx® Plus (2455 kg) was applied to the balance of the plume as aqueous slurries using temporary direct push points to a maximum depth of 17 meters below ground surface.


Three months post-amendment application, the size of the plume area was reduced by 70% and Florida Groundwater Target Cleanup Goals (similar to MCLs) were achieved within the PermeOx® Plus application area and have been maintained through four consecutive quarterly monitoring events. Initial results in the Klozur® CR application area showed near complete treatment of lighter hydrocarbons, and higher concentrations of heavier hydrocarbons which is likely attributable to high-pH induced desorption from soils or dissolution from the NAPL.