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2022 ANNUAL GROUNDWATER MONITORING REPORT TEICHERT AGGREGATES AND GRANITE CONSTRUCTION VERNALIS AREA approximate depth of 250 feet beneath the Vernalis Central Phase 1 and 8 that appeared to divide the underlying aquifer into shallow and deep zones.This clay is most likely the Corcoran Clay Member of the Tulare Formation,which has been reported to extend beneath much of the San Joaquin Valley, including the present monitoring network area (Hotchkiss, 1972). Further,the investigation indicated that the direction of groundwater flow in the shallow zone was predominantly to the southeast. Since 1994,groundwater levels have been obtained from a total of sixteen wells(Figure 2).The Thoming irrigation well was destroyed in early 2013.Since 2006,water level measurements in the irrigation well 4S/6E-6A1 have been precluded by an obstruction at a depth of approximately 100 feet(bgs). From fall 2018 through 2020,water level measurements in the Koster irrigation well were precluded by instrumentation of the California Department of Water Resources that lodged in the well casing. From 2016 through 2020,water level measurements in the Rustan well were infrequent due to site access limitations. In August of 2022,the Petz irrigation well was removed from the monitoring network when, after installation of a pump, it was determined that the well was out of plumb,therefore, precluding the installation of a sounding tube. Until spring 2021,South Tracy#3 had an obstruction at approximately 271 ft bgs and was only accessible for water levels that were above the obstructed depth. Prior to 2019, port access at the Granite#3 well had been difficult and only a few measurements had been obtained since this well was incorporated into the network in 2006. During spring 2019,the pump was removed from Granite#3 and water levels were obtained through fall 2021 when the sounding port was sealed. In November 2022, Granite#3 was accessible for water level measurements again when the welds were removed from the well head cover plate and water levels could be obtained from inside the well casing. In fall 2017, Granite#4 and Brown's New well were rehabilitated.After the rehabilitation,the sounding port at Granite#4 was obstructed at approximately 370 ft bgs (approximately 285 ft bgs starting in 2020)and was only accessible for water levels that were above the obstructed depth. From February 2021 to February 2022,the obstruction was no longer present and water level measurements were successfully obtained. In spring 2022, an airline was installed to an unknown depth and since then, psi readings have been collected. An airline was installed in the Brown's New well to obtain water levels, but it was destroyed by wildlife in spring 2018 making the well inaccessible for water level measurements.The airline was repaired, and pressure readings were obtained in 2019 and spring 2020. In summer 2020,the pump was temporarily removed, and a water level was obtained. By fall 2020,the pump was re-installed, however there was no longer an airline and no access to the well for water level measurements. In 2021,the well was accessible for water level measurements, however,the well has been pumping during most monitoring campaigns. In 2019,the Granite#5 production well was incorporated into the monitoring program. Pressure readings were obtained in its airline but due to a leak in the airline,the pressure readings are not representative and therefore were not converted to depth to water or water level elevations. In fall 2021,the pump was removed from the well and there was no access for a water level measurement. The groundwater quality network consists of 2 wells upgradient from the Vernalis plant(Hall and Faulkner domestic wells), 1 well onsite (South Tracy#3 production well), and 2 downgradient wells LUHDORFF&SCALMANINI CONSULTING ENGINEERS 2