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INTRODUCTION The following report describes a pilot test of the C-SpargeTm process for remediation of dissolved chlorinated solvents from ground%%ater The test was conducted b} Mateboer Milieutechniek B V for the Provincial Government of Utrecht at Rembrandt Street in Bilthoven, The Netherlands,from March 27, 1997 through April 4, 1997 The test involved installation of a C-Spargel well (TW), some additional monitoring wells (four 2-inch ID),the use of previously existing miniwells, and a fire well across the site THE C-SPARGETm PROCESS where The C-SpargeTm process consists of a combination of in-situ air stripping, dissolved chlorinated solvents(like PCE,TCE,DCE or vinyl chlonde) are extracted from tee:..—�� 4L _ in 1�'►^ - — - - -' trichloroethene(TCE),-then reacts with encapsulated ozone in gas/gas reaction described by the Criegee mechanism as a pnmary ozonide The ozonide is very unstable,decomposing to form a carbo 1 oxide which reacts with water(hydrol as it exits the bubble to eld reaction end _ products Cl-,H2O, and CO2(Masten, 1996) This is a very clean reaction sequence since the TCE is concentrated in the fine bubbles to react with ozone on a mole-to-mole basis The concentration of ozone in the bubbles is matched to the expected TCE concentration The process focuses ozone reaction selectively to air-stnppable compounds which invade the bubbles. As a result, Othe encapsulatedaditional ozone concentration is maintained at a low multiplier of the stnppab is available for side reactions with other dissolved organic compounds which have low Henry's numbers Primary reactions do not create any intermediate products because the reactions proceed so rapidly and bubble rise times are quite long. As of yet,the only identified end products have been inorganic(chloride, carbon dioxide,bicarbonate,nitrate,sulfate, and dissolved oxygen) Other organics may be produced,but at levels below normal detection- SM DESCRIPTION lume of The field test site is positioned in a small park area midway on a long p predominantly trichloroethene(TCE)onginaung at a commercial building and traveling over 244 m(800 ft) across a predominantly commerceal� residentialbdeposits iGroundwaThe ter�xists at a on lies in a thick fine sand deposit which contains gra depth of 2.5 m(8 2 ft)below grade. About one-half of the area of groundwater overlying the TCE plume is contaminated with dissolved hydrocarbon (BTEX)from a nearby commercial fuel spill. Soil borings taken by Tauw Engineering in the vicinity of the plumeshowed over mlow (19.7 surface loam extending to 3 m ells to(6 6 ft)deep Fine sand occurred in many A thick cla ft) deep Often gravel layers were intercepted at 4 m(13 ft)to 6 m(19 7 ft) deep Y layer,which probably serves as a bottom confining layer,was found at 38 m to 40 m(124 7 ft to 131 2 ft)deep. A hydraulic conductivity(K)of 7 5 x 10-2 cm/sec has been estimated for the sand deposits. Previous groundwater sarnpling had identified a narrow, long HVOC plume on two transects (A-A' and BB") extending from a source near A(wells 120 and 121) at a commercial facility to under Rembrandt Street, and ending under another commercial comptex The Bowe f 140)near Rembrandt Street(Figure 1) The distance was about 225 m(738 ft)Ict P 2