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2022 ANNUAL GROUNDWATER MONITORING REPORT TEICHERT AGGREGATES AND GRANITE CONSTRUCTION VERNALIS AREA 1 INTRODUCTION Luhdorff and Scalmanini,Consulting Engineers(LSCE) has prepared this 2022 Groundwater Monitoring Report on behalf of Teichert Aggregates(Teichert) and Granite Construction Company(Granite)for their quarry excavation operations in the Vernalis area of southern San Joaquin County, California (Figure 1). Teichert's plant is located at 36314 South Bird Road, Tracy,CA 95304(Figure 2).The Teichert Plant operates under Quarry Excavation No. QX-91-5 for Teichert Vernalis Central (previously referred to as Lone Tree) and PA-0500847 for Teichert Vernalis West and East. Teichert Vernalis Central mining commenced in 1998 and West and East commenced in 2014. Granite's plant is located south of the Teichert Vernalis Central property at 37400 South Bird Road,Tracy,CA 95304. Granite's plant operates under its Revised Conditional Use Permit for Quarry Excavation and Excavation Plan No. QX-94-1 (Granite's permit) and its approved Groundwater Monitoring Plan (LSCE, 2009). Phase I mining commenced in late 2007. All phases of the excavation are permitted for dry pit operations.The maximum mining depth at the Teichert Vernalis Central and Granite facilities shall not exceed 150 feet below ground surface (bgs) and the Teichert Vernalis West and East mining depths will reach approximately 225 feet bgs.Actual allowed mining depths may be reduced by San Joaquin County based on groundwater level elevation data developed by the monitoring program. Between 1995 and 2008, Teichert submitted annual groundwater monitoring reports for compliance purposes for its Teichert Vernalis Central (Lone Tree)excavation operations. Starting in 2009, comprehensive groundwater monitoring reports have been prepared to satisfy both Teichert's and Granite's permit requirements related to groundwater monitoring and reporting activities. 2 GROUNDWATER MONITORING ACTIVITIES Teichert's permits requires a minimum of 10 wells to be located around the general perimeter of the permitted mining area for quarterly groundwater level monitoring. In addition,the permit requires 5 wells (two upgradient from the project site,two downgradient from the project site, and 1 on site)for groundwater quality monitoring. Groundwater quality monitoring shall include, at a minimum,general mineral analyses,and nitrate. Wells used for domestic purposes shall also be tested for bacteria.The permit does not specify a frequency for groundwater quality monitoring activities. Since the inception of the monitoring program in 1994 and through 2009,groundwater quality sampling was conducted on a quarterly schedule together with groundwater level measurements. Groundwater quality monitoring was reduced to a semi-annual schedule in 2010.The required reporting frequency of monitoring results is annual. The wells for the monitoring network were selected based on a reconnaissance groundwater investigation conducted by LSCE in 1991 and 1992(LSCE, 1992). Results indicated that the depth to groundwater ranged between 80 feet beneath the valley floor to the northeast and 250 feet beneath the mountain flanks to the southwest. In addition, a confining clay was identified beginning at an LUHDORFF&SCALMANINI CONSULTING ENGINEERS