Contaminant Guide

Arsenic in Drinking Water: Testing, Limits & Filters

Arsenic is naturally occurring in many aquifers — tasteless, odorless, and only knowable by test. Here's how to read your numbers and match treatment without overbuying.

Last updated: July 2026 · Crystal Flow H2O Editorial · Ships nationwide · Direct install in Northern California

Why arsenic shows up

Arsenic occurs naturally in rock and soil and dissolves into groundwater. It’s a documented concern across parts of the western U.S., the upper Midwest, and New England — and in Central Valley / Sacramento-region groundwater communities (including documented EWG detections in Elk Grove).

EPA limits vs health guidelines

The federal MCL is 10 ppb. EWG’s health guideline is far stricter (0.004 ppb). A result can be “legal” and still above health-protective guidance. Always read both numbers on your report.

How to test

Full testing guide · ZIP lookup

Treatment options that work

Common approaches: adsorptive media (including specialized iron-based or ceramic media), reverse osmosis, and ion exchange configured for arsenic speciation (As III vs As V matters). Point-of-use at the kitchen is often the right economic choice; whole-home arsenic treatment is used when multiple taps need coverage.

Crystal Flow / TipaTech options

Local proof point: Elk Grove arsenic, chromium-6 & PFAS profile.

Have an arsenic number on your report?

Send the PDF or read the number on a 10-minute call — we’ll say whether T-18, Arsenic Extension, LotusDY, or a different path fits.

Call (916) 400-0725 Arsenic Extension FAQ

Ships free nationwide. Direct install in Northern California; partner installers coordinated elsewhere on request.

FAQ

Can I taste arsenic?

No. Testing is the only way to know.

Does a water softener remove arsenic?

No. Softeners target hardness ions, not arsenic.

Is reverse osmosis required?

Not always. Depends on concentration and speciation. Many homes do well with adsorptive media + a selective-membrane drinking tap. Confirm with post-install testing.

Take the next step

What you read about doesn't have to be your problem.

Three ways to start — whichever feels right. All free, no signup, real humans.

Prefer email? info@crystalflowh2o.com · Or use the contact form.

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