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RO Membrane Selection for San Antonio, TX Water

San Antonio Water System (SAWS)
PWS ID: TX0150018
2025 water quality report

What's in San Antonio's Water

Reported values from San Antonio Water System (SAWS)'s 2025 water quality data. Feed water chemistry drives membrane choice, operating pressure, and cleaning frequency.

Source water

Groundwater from the Edwards, Carrizo, Simsboro, Trinity and Wilcox aquifers, surface water from Canyon Lake, plus purchased supplies (Vista Ridge, Canyon Regional WA, GBRA Western Canyon, Schertz-Seguin and others)

TTHM note

highest single-location yearly average as printed — above the 80 MCL number but not a violation under LRAA compliance math; purchased GBRA Western Canyon water ran 71.3

Barium0.125 ppm
Beta emitters5.5 pCi/L
Chlorine1.46 ppm
Combined radium1.5 pCi/L
Copper 90th0.187 ppm
Dibromochloromethane9.9 ppb
Diethylhexyl adipate1 ppb
Fluoride0.69 ppm
HAA530.6 ppb
HAA5 (range)0-30.6 ppb
Lead 90th1.6 ppb
Lithium15.6 ppb
Lithium (range)13.1-17.2 ppb
Nickel0.004 ppm
Nitrate2.45 ppm
Nitrate nitrite1.83 ppm
Selenium3.1 ppb
Thallium0.61 ppb
TTHM86.2 ppb
TTHM (range)0-86.2 ppb
Uranium1.7 µg/L

Our Recommendation for San Antonio

San Antonio's water comes overwhelmingly from limestone aquifers — the Edwards above all — which makes it famously hard, though SAWS publishes those mineral numbers only to the state database, not in this report. What the report does show: disinfection byproducts pressing the limit, with the worst-site TTHM yearly average printed at 86.2 ppb against an 80 MCL (compliant only via running-average math), and purchased surface water running 71.3. For equipment on SAWS supply, a brackish NanoH2O (formerly LG) BW 400 R G2 removes the DBPs and the limestone scaling load in one pass.

Membranes Matched to This Water

The Industry Workhorse

NanoH2O (LG) BW 400 R G2

  • 99.8% salt rejection
  • 11,500 GPD · 225 psi
  • 400 ft² active area
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Running RO on San Antonio water?

Send us your system size and feed water details — we'll spec the right membrane for your operation and quote same-day shipping.

Data Source

Water quality values on this page are taken from San Antonio Water System (SAWS)'s 2025 published water quality report (PWS ID TX0150018). Values are utility-wide averages; water at a specific site can vary. For membrane selection on a critical system, test your actual feed water.

View the official report