Abstract: The present embodiments provide methods, systems and processes for use in treating soil and/or ground water. Some of these embodiments provide systems for use in remediating contaminants, where the system comprises: a plurality of gas product sources positioned at a geographic location to be treated; a distribution manifold coupled with the plurality of product sources; a plurality of diffuser coupled with the distribution manifold and is positioned within separate wells within the soil; and a controller coupled with the plurality of product sources and the distribution manifold. The controller: activates one or more of the product sources to generate, locally at the geographic location, one of five different gas products in accordance with a first step of a treatment schedule; and communicates with the distribution manifold to direct the generated one of the five gas products to a predefined one of the diffuser.