All Cities
Local Water DataHidalgo County

RO Membrane Selection for Mercedes, TX Water

City of Mercedes
PWS ID: TX1080007
2025 water quality report

What's in Mercedes's Water

Reported values from City of Mercedes's 2025 water quality data. Feed water chemistry drives membrane choice, operating pressure, and cleaning frequency.

Source water

Surface water from the Rio Grande River blended with groundwater

Total Dissolved Solids

1250 mg/L

Brackish-range TDS — well above the EPA secondary standard of 500 mg/L; brackish water membranes are designed for exactly this feed

Hardness

325 mg/L as CaCO3

Very hard — high scaling risk — expect antiscalant dosing, conservative recovery, and a regular cleaning schedule

Arsenic2.6 ppb
Asbestos mfl0.197
Barium0.0643 ppm
Beta emitters7.5 pCi/L
Bicarbonate204 ppm
Calcium77 ppm
Chloramines2.18 ppm
Chloride294 ppm
Combined radium1.5 pCi/L
Copper 90th0.433 ppm
Fluoride0.8 ppm
Gross alpha3.3 pCi/L
HAA516.1 ppb
Lead 90th4 ppb
Lithium56 ppb
Lithium (range)49.6-61.4 ppb
Magnesium32.2 ppm
Manganese0.0173 ppm
Nickel0.0025 ppm
Nitrate0.61 ppm
Pfhxa0.0033 ppb
PH7
Potassium7.25 ppm
Sodium279 ppm
Sulfate389 ppm
Total alkalinity167 ppm
TTHM51.4 ppb
TTHM (range)20.9-71.6 ppb
Yttrium125.4 ppb
Zinc0.0052 ppm

Our Recommendation for Mercedes

Mercedes remains the heaviest water in the Valley database: TDS 1250 mg/L (over the 1000 secondary standard), hardness 325, sulfate 389 (over 300), chloride 294, sodium 279. Scaling and salinity are both live problems — a brackish NanoH2O (formerly LG) BW 400 R G2 (or higher-flow BW 440 R G2) with proper antiscalant dosing and conservative recovery is the build. The 2025 report also discloses lithium at 56 ppb and yttrium at 125 ppb — unusual detections that RO rejects along with the salts.

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
View membrane

Maximum Active Area

NanoH2O (LG) BW 440 R G2

  • 99.8% salt rejection
  • 12,650 GPD · 225 psi
  • 440 ft² active area
View membrane

Running RO on Mercedes 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 City of Mercedes's 2025 published water quality report (PWS ID TX1080007). 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