Lodi Water Hardness & Quality Report (2026)

The City of Lodi Water Department serves approximately 68,272 residents in Lodi, San Joaquin County, California. Water is sourced entirely from groundwater, with 28 wells including deep wells and one artesian well, supplemented by three reservoirs for storage. There are no surface water treatment plants; low-level chlorination is applied proactively, with filters installed on seven wells to address specific contaminants. The utility's mailing address is 2001 West Turner Road, Lodi, CA 95242.

The supply originates within the Eastern San Joaquin Groundwater Subbasin, a critical aquifer in California's San Joaquin Valley. Water percolates through Quaternary alluvium and Tertiary sedimentary rocks, including the Pleistocene Laguna Formation and older Plio-Pleistocene deposits rich in calcium and magnesium from weathered Sierra Nevada volcanic and granitic materials. Long groundwater residence times enhance mineralization, and the basin's geology — shaped by Sierra Nevada erosion — yields elevated dissolved solids typical of hard Central Valley aquifer supplies.

Very hard water promotes significant scale buildup on fixtures, pipes, and heating elements, reducing efficiency in water heaters, dishwashers, and washing machines by up to 50% over time. White crusty deposits on glassware, faucets, and appliances are common, alongside soap scum and dry skin from poor lathering. Regular vinegar descaling, installing scale inhibitors, and flushing water heaters annually help mitigate issues; a water softener is strongly recommended for households to extend appliance life and improve cleaning. Water quality is excellent, earning an A grade with no EPA violations; all 191+ tested substances meet MCLGs, with no lead or copper action level exceedances and trace DBCP filtered where needed on specific wells.