ARCHIVED REPORTS_1988_1 - Laserfiche WebLink

Home Browse Search

u 1 n C 1 The following monitoring system is proposed to bring the facility into compliance with Title 23, Subchapter 15, Article 5 of the CAC. The proposed system is based on the current understanding of hydrogeologic conditions at the site. Following installation of the proposed system, new information on the hydrogeologic conditions will be evaluated and the need for additional wells or characterization will be assessed. The proposed ground -water monitoring system is intended to fulfill SWAT detection monitoring requirements, as well as to provide back- ground and compliance points for ongoing monitoring according to Subchapter 15 requirements. The proposed ground -water monitoring network includes three deep wells and two shallow wells. Proposed surface -water sampling is discussed in Section III.B. No unsaturated (vadose) zone monitoring is proposed for this site, as discussed in Section III.E. Chemical characterization of the unsaturated zone will be performed as detailed in Section III.F. The results of a recent investigation into subsurface conditions at the site indicate that the Corcoran Clay Member of the Tulare Forma- tion lies in the shallow subsurface of the northern half of the landfill (EMCON Associates, 1988). A perched zone of ground water may occur locally on or within the Corcoran Clay at an approximate depth of 20 feet. A deep regional aquifer occurs at an approximate depth of 250 feet. Therefore, to comply with Section 2553(a) of Subchapter 15, which requires detection of fluids at the earliest possible opportuni- ty, the proposed monitoring network is designed to sample ground water in the shallow perched zone (if confirmed by further drilling), as well as the deep regional aquifer. Initially, five monitoring wells are proposed: three monitoring wells to monitor the deep regional aquifer and two shallow wells to monitor any perched ground water. Well MW -1 (see Figure 2) is intended to D cmrnn