A gasoline release from an underground storage tank (UST) at a rural corner store/service station in Santa Cruz County, California resulted in impacted groundwater. Of major concern was a dissolved plume of methyl tertiary butyl ether (MtBE). The MtBE plume extended over 1,200 feet and impacted a domestic supply well that provided water to several households. The MtBE plume was delineated using groundwater sampling via temporary Geoprobes and diffusive sampling. With an understanding of the impact plume, a closed-loop groundwater extraction and sparge barrier system was designed, constructed, and operated. Additionally, drinking water was temporarily supplied to households whose water supply was impacted, while a replacement water supply well was located and constructed, the distribution system was replaced, and the newly installed water supply system was activated.