Loureiro completed treatability testing of in situ chemical oxidation (ISCO) for contaminated soil and groundwater at an active, high security, manufacturing facility in Maine which produces specialty aircraft components. The treatability testing assessed oxidant effectiveness for site contaminants of concern (COCs) including tetrachloroethene (PCE), 1,1,1-trichloroethane (1,1,1-TCA), and 1,4-dioxane, all in the milligrams per liter (mg/L) concentration range. Several ISCO technologies were evaluated, including heat-activated persulfate, chelated iron-activated persulfate (to bind up transition metals in the soil matrix to overcome potential interferences with the oxidant), alkaline activated persulfate (AAP), and an industry available packaged ISCO product. Peroxide and ozone were eliminated from consideration due to client concerns with enhanced vapor migration into the active operating facility that ran 3 shifts of workers directly above the shallow target treatment area.
The treatability test results indicated that AAP achieved the greatest reduction in COCs in site soil and in groundwater. The results were used to design and implement a full-scale application of AAP at the site. Annual post-application monitoring confirmed that the site goals were met and no rebound occurred.
