Iron and manganese in well water: New York limits and staining

As of 2026-10-07. From the New York State Department of Health (NYSDOH) and US EPA. Private wells aren't regulated like public water: NYSDOH recommends public-water limits for private wells. Sources are linked below.

The limits

TestNew York (NYSDOH Fact Sheet #3)US EPA secondary standard
Iron0.3 mg/L: "Rust-colored staining of fixtures or clothes"0.3 mg/L: "rusty color; sediment; metallic taste; reddish or orange staining"
Manganese0.3 mg/L: "Black staining of fixtures or clothes; potential nervous system damage"0.05 mg/L: "black to brown color; black staining; bitter metallic taste"
Iron plus manganese0.5 mg/L: "Rusty or black staining of fixtures or clothes"(none)

These limits apply to public water systems. Private wells aren't required to meet them, but health departments use them as guidance.

NYSDOH says the limits in its fact sheet "are based upon requirements for Public Water Supply systems and are also recommended for use on individual residential systems." EPA's numbers are different in kind: EPA calls them "non-mandatory water quality standards" and says "EPA does not enforce these" secondary levels. EPA groups iron and manganese with standards for color, taste and staining.

Signs to test for them

NYSDOH's Fact Sheet #3 (based on an EPA table) suggests these tests:

How often to test

NYSDOH's Test Your Well page lists iron and manganese ("cause rust or black staining of fixtures or clothes") under "Every 3-5 years." Use a NYSDOH ELAP-certified lab.

If your result is high

Before you buy treatment, confirm the result with an ELAP-certified lab and ask your local health department about it. The Minnesota Department of Health's home water treatment fact sheet compares common unit types and the contaminants each is designed to remove. Reading the rest of your report? See well water test results explained.

Common questions

What level of iron in well water is too high in New York?

NYSDOH Fact Sheet #3 lists 0.3 mg/L for iron, with the concern "Rust-colored staining of fixtures or clothes." For iron plus manganese together it lists 0.5 mg/L. These limits apply to public water systems. Private wells aren't required to meet them, but health departments use them as guidance.

Is manganese in well water only a staining problem?

Not only. NYSDOH Fact Sheet #3 lists 0.3 mg/L for manganese, with the concern "Black staining of fixtures or clothes; potential nervous system damage." These limits apply to public water systems. Private wells aren't required to meet them, but health departments use them as guidance.

How often should I test for iron and manganese?

NYSDOH's Test Your Well page lists iron and manganese under "Every 3-5 years."

Got your results back? The NY guide explains about two dozen common tests, with a fill-in worksheet.

Get the NY guide (PDF), $19

Instant download. 14-day no-questions refund. Printable guide (PDF), New York Edition 1.0.

Sources

Related guides