RO Membrane Selection for Mission, TX Water

Mission's 2025 report finally publishes the mineral load: total hardness 318 mg/L as CaCO3, sulfate 299 (right at the 300 aesthetic limit) and sodium 153 — hard, scaling-prone Rio Grande water — alongside iron (1,080 ppb) and aluminum (637 ppb) that both run over their aesthetic limits and can foul membranes and stain equipment. On the regulated side the disinfection-byproduct story is the sharp edge: TTHM reached 81.7 ppb, at or above the 80 ppb MCL on a single reported value (still compliant on the running-average basis), with cyanide climbing to 120 ppb. For process water that cannot absorb that DBP variability or the hardness and iron scaling, a brackish NanoH2O (formerly LG) BW 400 R G2 with antiscalant and a conservative recovery target knocks down the minerals, iron and DBP precursors in one pass.