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:i G N — the destruction of petroleum hydrocarbons, and other volatile organic compounds, are well-documented (Watts, 1991, 1992 and 1994). Leetham et al (2002) describes gasoline and MTBE destruction using chemical oxidation. Although Fenton's chemistry has been documented for well over 100 years, it has been employee safety and handling issues that have kept large numbers of environmental contractors from using in- situ chemical oxidation technology. Although this technology can be used safely, significant safety planning, worker training, personal protective equipment, on- site supervision and monitoring must be an integral part of all oxidation projects. Concerns: Under certain conditions, the injection of an oxidant such as hydrogen peroxide into the subsurface potentially oxidizes and remobilizes certain soluble metals under certain conditions. The highly toxic, oxidized variety of chromium, hexavalent chromium Cr(VI) can be formed from the reduced variety, trivalent chromium Cr(". The amount of Cr(VI) mobilized will depend on the background chromium concentrations in the soil. However, any hexavalent chromium formed from the reaction with an oxidant should become reduced and attenuate back to trivalent chromium within a short time frame and distance. Hydrogen peroxide works well and has been accepted by the CRWQCB-LAR Due to the limited lifespan of the hydrogen peroxide, AA&A proposes using hydrogen peroxide with persulfate, in order to make a longer-lasting treatment chemistry. AA&A also recommends bench testing other persulfate treatments for comparisons. Hydrogen Peroxide with Sodium Persulfate and amendments Persulfate oxidation uses sodium persulfate catalyzed or activated by hydrogen peroxide (with ferrous sulfate and sulfuric acid or other acid), or chelated iron complex to produce sulfate free radicals that attack contaminants. The reaction mechanism associated-withTersuifate-baseetprocesi3--isskowrrbulaw 52082- F 4 2SO4" Where, S2O82- = Persulfate (Sodium, Ammonium or Potassium), SO4`= Sulfate free radical BothH202 and activated persulfate oxidizers will work effectively to destroy the site contaminants. The by-product generated by injecting activated persulfate is sulfate. The secondary drinking water standard for sulfates of 250 mg/L. To treat hydrocarbons, sodium persulfate is activated. The basic reaction is: 52082- q 2SO4- Where 52082- = Persulfate (Sodium, Ammonium or Potassium), SO4 = Sulfate free radical 4