Whole House Water Softeners in Seagoville

Seagoville's Water Billing page states the arrangement plainly: the city contracts with the City of Dallas, which provides the purification, and the water bought from Dallas is stored in the Seagoville water tower and reservoir. The city's 2025 water quality report names Bachman Lake among its sources, and Dallas's December 2023 memorandum identifies Bachman as the site of one of Dallas's three plants, one of the two that receive Ray Roberts, Lewisville and Grapevine water down the Elm Fork of the Trinity; the third, East Side in Sunnyvale, treats lakes Hubbard, Tawakoni and Fork. Seagoville's report also walks through a treatment sequence: aeration to oxidize iron, polyaluminum chloride and soda ash to gather particles into floc that settles out, chlorine, filtration through fine coal and silicate sand, chlorine again, and finally soda ash to set the finished water's pH and alkalinity, fluoride, and a corrosion inhibitor, before the water is pumped to underground reservoirs and water towers. The report adds that the source water assessment that applies is the TCEQ's assessment of Dallas's sources, not a Seagoville one.

None of those steps is softening, and the report's results tables, with a City of Seagoville column beside a Dallas column, have no hardness line. So the figure to use is Dallas's. The 2023 memorandum puts Dallas's system at 120 to 155 mg/L as calcium carbonate, in grains roughly 7 to 9 per gallon, and the USGS scale, which calls 121 to 180 mg/L hard, puts all but the very bottom of that range in the hard class. The soda ash step the report describes adjusts alkalinity, which is a different measure from hardness: alkalinity is the water's capacity to neutralize acid, while hardness is its calcium and magnesium content. Seagoville's report does not print an alkalinity result either. With no city-level hardness figure in the report, this page gives none for Seagoville.

At a Seagoville tap, the tower matters more than the lake. Water from Dallas fills the city's reservoir and tower, and from there gravity and the city's pumps set the pressure on each street; a house below a full tower sees more pressure than one near its level. The supply described in the 2025 report is purchased surface water only; it names no well, so there is no second water to blend in and the mineral content at every address is the Dallas content. The Seagoville column of the results table, covering lead and copper, disinfection by-products and chlorine, is the only part of the report that is the city's own measurement; everything upstream of the tower is Dallas's. When sizing a softener, use 9 grains per gallon, the top of the Dallas range, and let the free water test pin down the exact figure at your own tap.

Sources: City of Seagoville: Water Billing · City of Seagoville 2025 Water Quality Report · City of Dallas memorandum to the Quality of Life, Arts and Culture Committee, December 1, 2023 · USGS Water Science School: Hardness of Water