Laserfiche WebLink
Groundwater Monitoriny Well Conslructlon Workplan <br /> January 2024 <br /> Background <br /> The San Joaquin County Public Works Department is the lead agency for the TSb Sustainable <br /> Groundwater Management Act implementation. The Subbasin is being managed by six <br /> Groundwater Sustainability Agencies (GSAs): BCID,Byron Bethany Irrigation District, the <br /> cities of Tracy and Lathrop, San Joaquin County, and Stewart Tract. Together they created and <br /> adopted the TSb GSP. <br /> During preparation of the GSP, groundwater levels in the Upper and Lower aquifers were <br /> evaluated. Some existing monitoring wells(irrigation supply wells) were found to have <br /> inadequate sanitary seals and gravel packs crossing the Corcoran Clay. Groundwater levels in <br /> these wells, though penetrate below the Corcoran Clay, had ground water levels representative of <br /> the Upper Aquifer. The GSP identified the need for dedicated monitoring wells to resolve <br /> groundwater levels in the Upper and Lower aquifers. <br /> In 2019, the GSAs applied to DWR for Technical Support Services to construct new monitoring <br /> wells in the Subbasin. In 2022,DWR committed to drilling up to six new monitoring wells in the <br /> Subbasin, including MW-204. <br /> One of the six monitoring wells, MW-203, was drilled to a depth of about 1,350 feet, about 2 <br /> miles northwest of MW-204, and provided significant information about the geologic conditions. <br /> The knowledge obtained from MW-203 was used to design MW-204. Ground surface at MW- <br /> 203 is about 140 feet amsl while MW-204 ground surface is about 170 feet amsl. Therefore, to <br /> penetrate the same aquifers encountered at MW-203, if the aquifer lie horizontal,they would be <br /> encountered about 30 feet deeper at MW-204 location. <br /> I <br /> GEI Consultants, Inc. 5 <br />