Abstract: A system for decontaminating a soil and groundwater region. The system has a well manifold assembly comprising a conduit adapted to be inserted into a contaminated area of the soil and groundwater region, a vacuum system for withdrawing fluid and vapor from the soil and groundwater region, and a remediating fluid injection system in fluid connection with the conduit. The remediating fluid injection system is adapted to inject a remediating fluid into the soil and groundwater region for treating contaminants in the soil and groundwater region. The conduit is linked to both the remediating fluid injection system and to the vacuum system. The vacuum system is operated to perform a dual-phase extraction of fluid and vapor from the soil and groundwater region to create a negative pressure in the soil and groundwater region. Next, remediating fluid is injected into the soil and groundwater region.