Whole House Water Softeners in Grapevine

Grapevine treats lake water at a plant of its own and buys the Trinity River Authority's treated water at the same time. Its 2025 report says the city draws surface water out of Lake Grapevine and buys from the authority, whose Lake Arlington supply is pumped in from Cedar Creek and Richland-Chambers, and that both the Grapevine and authority plants put the lake water through a series of treatment steps before sending it out across a distribution network of more than 328 miles. A 2015 report put the split at 70 percent authority water and 30 percent Lake Grapevine. The city plant is getting its first major work since 1989: an $18 million project approved for design in May 2024 adds three filters, rehabilitates four clearwell storage tanks and replaces another, and studies further removal of PFAS compounds. The city's 2019 report listed the chemistry both plants apply to lake water, among them ozone, alum, polymer, potassium permanganate, ammonia and caustic soda.

The report's tables run two columns, City of Grapevine and Trinity River Authority, and the hardness row is where the 110 ppm figure lives: 110 ppm total hardness, as calcium carbonate, in the authority column, sampled in 2025, with the Grapevine column marked NA. The same column gives a calcium reading of 38 ppm, magnesium of 3.68, alkalinity and bicarbonate both 81, sodium 27.5, dissolved solids 194, sulfate 48.9 and a pH of 8.8. The report puts that hardness down to calcium and magnesium in solution. So 110 ppm, moderately hard by the USGS yardstick and roughly 6.4 grains per gallon, is a measurement of the authority's water, which is the larger share of what Grapevine delivers, and the 2025 report prints no hardness result for the water the city's own plant makes from Lake Grapevine, so this page carries one figure, not two.

That leaves a Grapevine homeowner with a known figure for most of the supply and an unmeasured share from the city plant, and the mix at any one tap depends on which plant feeds that part of the system, how hard the city plant is running that season, and how much of the 70 percent authority share reaches that street; the 70 percent figure is a decade old, so the share may have moved since. Lake Grapevine is reservoir water like Lake Arlington, but the city does not print its number in the current report and this page will not guess it. Size the softener with room above 110 ppm rather than exactly to it, so the unit handles whatever the Grapevine plant's share adds, and let the free water test say what your tap carries; that is the number we set the softener to.

Sources: City of Grapevine, 2025 Water Quality Report · Community Impact, February 17, 2015: Prepare for Stage 2 cutbacks, Trinity River Authority warns · Community Impact, May 23, 2024: Grapevine council approves water treatment plant contract · City of Grapevine, 2019 Annual Drinking Water Quality Report · USGS Water Science School: Hardness of Water