Selma Water Hardness & Quality Report (2026)

Selma, California, in Fresno County in the heart of the San Joaquin Valley — the self-proclaimed "Raisin Capital of the World" — receives its municipal water from the City of Selma Public Works Water Division, drawing from local groundwater wells tapping the Central Valley alluvial aquifer and supplementary Kings River irrigation canal surface water supply. Selma's location on the fertile valley floor between the Sierra Nevada and the Coast Ranges places it squarely in California's most intensively irrigated agricultural landscape, where both surface water and groundwater reflect decades of agricultural and mineralogical interaction with deep valley sediments.

The hard 165.5 mg/L hardness and elevated TDS of 494.4 mg/L reflect the San Joaquin Valley's complex alluvial geology. The deep Central Valley aquifer beneath Fresno County consists of Pliocene and Pleistocene alluvial fan deposits from ancient Sierra Nevada drainage — sands, gravels, and silts derived from granitic and metamorphic Sierra terrain mixed with marine sediment residues from earlier Miocene incursions into the valley. Irrigation percolation over generations has concentrated dissolved minerals in the shallow groundwater zone, and Kings River surface water contributes additional dissolved loads from its Sierra foothill transit through calcareous sedimentary formations.

At 165.5 mg/L, Selma residents experience hard water with consistent mineral effects throughout the home. Kettles and coffee machines accumulate white scale within weeks, dishwashers benefit from rinse aid and periodic descaling treatments, and the moderately elevated TDS produces a perceptible mineral character in unfiltered tap water. Quarterly descaling of heating appliances is recommended. The PFAS level of 6.8 ppt warrants a certified drinking water filter — San Joaquin Valley communities face broad groundwater quality pressures from agricultural, industrial, and military sources throughout the region.