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Calculator 🇺🇸 US: EPA standards as a guide — private wells are not regulated

Well water treatment sizing calculator

Enter the values from your well water lab report below and the calculator lays out the treatment equipment in the order the water flows — sediment filter, hydrogen sulfide, iron and manganese removal, carbon, softener, reverse osmosis, UV — and works out flows, brine and running costs. Private wells are not regulated by EPA [1], so your water is compared with EPA public-water standards as a guide [2].

Updated 2026-10-24 · every regulation and price links to its source at the bottom of the page. A guide, not a construction design.

Size the treatment for your well

Key parameters are marked with a dot: without TDS, hardness, iron, manganese, sodium, chloride, sulfate and the permanganate index the result is approximate. An empty field means «not measured», not zero. Hardness can be entered in grains per gallon (gpg) or mg/L as CaCO₃; ppm is the same as mg/L.

Size whole-house reverse osmosis →

In the app, with the same data

The result above is yours, free and without signing in. In the app the same data gives you more:

  • Water treatment from your test inside your house plan — the same treatment chain
  • See your house in 3D — outside with the roof, inside and as a walk-through
  • The plan as PDF and DXF to show a builder or an architect

No retyping: the values from this page are put into a new plan.

Sign up free — your data moves into the plan →I already have an account — sign in

What you typed stays in your browser until you move it into a plan yourself.

How does the calculator choose?

Order. A sediment filter always comes first [3]; hydrogen sulfide is removed before catalytic media [4]; then iron and manganese, carbon, the softener, a membrane and UV last.

Iron before the softener. A softener removes dissolved iron only incidentally — generally only when pH is above 6.7, hardness is 3–20 gpg and dissolved iron is below 5 mg/L [5]; our selection keeps the stricter softener inlet of 0.2 mg/L iron and 0.05 mg/L manganese [6]. Birm-type media needs pH 8 for manganese [7].

Bacteria. EPA public-water rules allow no E. coli [8]; when bacteria were found — or never tested on a well — UV goes last, on clear treated water [9].

This calculator gives equipment sizing estimates from the values you enter; it does not guarantee that the water is fit to drink. Only a certified laboratory test after installation can confirm that. Prices in US dollars come from US sources where we found them (sediment, iron, softener, UV and its lamp, reverse osmosis, salt); any other item is marked «≈» when it is converted from Ukrainian prices, or says «no local price found».

Frequently asked questions

Do I need an iron filter or just a water softener?

A softener handles dissolved iron only incidentally — generally when pH is above 6.7, hardness is 3–20 gpg and dissolved iron is below 5 mg/L [5]; oxidized (rusty) iron fouls the resin and needs a filter first. The calculator puts iron removal before the softener when the iron or manganese is above the softener inlet.

Which values does the water test need?

TDS, hardness, iron, manganese, sodium, chloride, sulfate and the permanganate index, plus bacteria (total coliforms, E. coli) and nitrate, which EPA limits for public water [10].

Does a water softener lower TDS?

No: it swaps calcium and magnesium for sodium, the dissolved solids stay [11].

Read also:Whole-house reverse osmosis sizing calculatorPrivate Well Water Testing in the US: What to Test, CostWell Water Treatment Systems: Types, Limits and NSF RulesWater Softener for Very Hard or Salty Well Water: What It Does

Sources

  1. US EPA — Private Drinking Water Wells (landing page) (US) · regulation · checked 2026-09-29 · source
  2. 40 CFR 143.3 Secondary maximum contaminant levels (National Secondary Drinking Water Regulations), § 143.3 (US) · recommendation · checked 2026-09-29 · source
  3. dvgw.de, Mechanisch wirkende Filter (DE) · regulation · checked 2026-09-29 · source
  4. Penn State Extension — Hydrogen Sulfide (Rotten Egg Odor) in Water Wells, Treatment options (US) · recommendation · checked 2026-09-29 · source
  5. Penn State Extension — Iron and Manganese in Private Water Systems, Water Softeners (US) · recommendation · checked 2026-09-29 · source
  6. ecosoft.ua (UA) · recommendation · checked 2026-09-29 · ~ · source
  7. lenntech.com, Conditions necessary for the use of Birm — Manganese Removal (US) · recommendation · checked 2026-10-16 · source
  8. 40 CFR 141.63 Maximum contaminant levels (MCLs) for microbiological contaminants (National Primary Drinking Water Regulations; Revised Total Coliform Rule), (c) (US) · regulation · checked 2026-09-29 · source
  9. Chautauqua County (NY) Environmental Health Services — Private Drinking Water Standard for Ultra Violet (UV) Light Disinfection System, Water Quality; installer checklist (US) · regulation · checked 2026-09-29 · source
  10. 40 CFR 141.62 Maximum contaminant levels (MCLs) for inorganic contaminants (National Primary Drinking Water Regulations), (b)(7)–(9) (US) · regulation · checked 2026-09-29 · source
  11. Montana State University Extension Water Quality — Hardness fact sheet, Treating Hard Water (US) · recommendation · checked 2026-09-29 · source

🌐 🇺🇦 За нормами України · 🇬🇧 UK regulations