Guide · Updated October 3, 2026

Manganese in Wisconsin Well Water

Black on a sink is a clue. It is not a specification. Until a Wisconsin-certified lab prints manganese in µg/L or mg/L on a sheet, a stain story, a neighbor’s tank, or a catalog is not a diagnosis. DNR’s manganese page names brown, black, or rust-black color, black staining on faucets, sinks, or laundry, and a metallic or off taste as common reasons to test. Those clues are still not a specification.

This page is a reading order for that sheet. It is not a medical consult and not a shopping list. Small amounts of manganese are part of a normal diet; this site will not turn a stain into a disease claim. High manganese is a test-then-class problem. Coliform or nitrate on the same sheet still goes to the health department first.

Private wells are unregulated. DNR’s private-well testing pages, EPA’s private-wells pages, and CDC’s well-testing guidance put the schedule on the owner. Nobody mails you a Consumer Confidence Report.

What 300 µg/L means — and what it is not

DNR’s groundwater enforcement standard and EPA’s lifetime health advisory are both 300 µg/L. DHS: at or above that line, people over 50 and infants under 6 months should stop using the water for drinking and for foods or beverages that take a lot of water; everyone should avoid long-term drinking use until a long-term fix is in place. That is a health-advisory / groundwater-enforcement comparison, not a private-well criminal statute that forces you to abandon the well overnight. DHS still recommends an alternative safe source for drinking and water-heavy cooking when results stay at or above that line.

EPA’s secondary drinking-water standards list manganese at 0.05 mg/L (50 µg/L) for aesthetic effects — black-to-brown color, black staining, and bitter metallic taste. That is an SMCL for public systems. It is not Wisconsin’s 300 µg/L health line and not a private-well legal limit. Do not call 0.05 mg/L a kitchen-tap statute, and do not confuse it with 300 µg/L.

USGS Water-Resources Investigations Report 90-4171 found manganese concentrations that exceeded Wisconsin’s then-current drinking-water standards in about one-quarter of sampled wells in the shallow aquifer system (iron exceeded in about one-third). That is a published sample set, not a county ranking. Your well is not a map. The Minnesota manganese page is the peer-state version of the same split.

Units. 300 µg/L = 0.3 mg/L. 50 µg/L = 0.05 mg/L. µg/L and ppb are the same magnitude here. If the sheet prints mg/L, convert before you compare it to DNR/DHS 300 µg/L or EPA’s 0.05 mg/L SMCL. How to read a well water lab report is the decoder.

Iron often travels with manganese. DNR’s iron brochure (DG-035) asks for manganese on the same conversation as iron. Iron in Wisconsin Well Water is the sister reading order. Hardness and pH change which oxidation/filtration class fits — see Hardness in Wisconsin Well Water. Hydrogen Sulfide in Wisconsin Well Water is a different job when the complaint is rotten egg.

How often Wisconsin says to test

On DNR’s Tests for Private Well Users (DG-023) and DHS private-well pages:

• Every year: coliform bacteria and nitrate.
• Manganese when water is brown or black, stains faucets or laundry, or has an off taste or odor — or when you already know iron/manganese geology is in play.

Manganese is the stain or advisory number you came for. It is not a reason to skip the yearly pair. If coliform or nitrate is flagged, stop. Call the local health department. Do not shop an oxidizing filter while that sheet is open. Nitrates in Wisconsin Well Water is the nitrate reading order. Arsenic in Wisconsin Well Water is a different job on the same inventory.

If you treat, sample after treatment for the tap you cook and drink from — unless you also need a raw-side number for a design. Ask for a second bottle if you need both. Retest to confirm a high result before you commit to a long-term fix.

Get a certified-lab µg/L — not a stain guess

Start at this site’s Wisconsin certified-lab inventory. Chemistry certification is DNR; bacteria certification is DATCP. A coliform certificate is not a manganese certificate.

Open DNR’s certified laboratory lists and the private-well testing page. Confirm drinking-water manganese (and iron / iron bacteria if offered) on the current chemistry list. Then call: private-well / residential sample, bottle, hold time. Nationwide index: certified labs by state. Lab news: /labs/wisconsin/news. Sibling pages: Iron in Wisconsin Well Water; Hydrogen Sulfide in Wisconsin Well Water; Hardness in Wisconsin Well Water.

Sample the cooking and drinking tap. Untreated: usually kitchen cold. Follow the lab’s hold-time instructions.

A store strip is a screen. Well water test kits explains that split. Tap Score / SimpleLab is an approved class example of a mail-in certified-lab kit — not a ranked pick. Pair it with a lab from /labs/wisconsin. Bacteria or nitrate still goes to the health department. See the disclosure.

Households with pregnant people and young children may be eligible for free or low-cost testing through a local health department when a burden blocks testing — that is an access path, not a substitute for choosing the right class after a paid sheet.

After the sheet: classes, not a catalog

Name the µg/L first. Then look a model up in the NSF drinking-water treatment-unit database. NSF is a claim on a listed model, not a badge this site awards. This page does not rank brands.

DNR/DHS options when manganese stays high: bottled water, a certified treatment device, or an alternative safe source / new well. Wisconsin wants treatment devices that appear on the DSPS-approved water treatment device list for the contaminant claim.

Usual classes for manganese (often paired with iron):

• Oxidation + filtration (aeration, chlorination, catalytic media, manganese greensand) when dissolved manganese needs to be oxidized then filtered.
• Ion exchange in limited chemistry windows — not automatic when manganese is already oxidized or when iron or organics foul the bed.
• Point-of-use options for drinking taps when a whole-house POE system is not the right fit yet — still must match the certified claim.

Whole-house iron and sulfur filters is the oxidation-class catalog page. Iron filter vs. water softener is the trap page. Treatment order after the pressure tank still applies: sediment first, iron/manganese oxidation next, softener last.

Hire a licensed plumber or licensed well/pump professional when the chemistry is messy. DNR customer service: 1-888-WDNRINFO. Ask about well-compensation grant eligibility only when DNR/DHS frames a public-health hazard path — that is a program, not a shopping coupon.

Manufacturer sites are catalogs, not rankings. SoftPro is an approved iron/sulfur whole-house filter class example that sits in the same oxidation/filtration conversation often used for manganese (tracked; see the disclosure):

• SoftPro
• SpringWell (official URL, application pending)
• US Water Systems (official URL, application pending)

If bacteria is present, stop. Health department first. A manganese filter on a contaminated well is the wrong Monday.

When the number is high — use the DHS order, not a catalog first

If the sheet is at or above 300 µg/L:

1. Retest to confirm.
2. Follow DHS drinking and food-prep advice (especially ages 50+ and infants under 6 months). Bathing, brushing teeth, and dishwashing are generally still OK per DHS manganese private-well guidance — that is their wording, not a medical clearance.
3. Then pick a long-term class: certified treatment, alternate source, or new well.

Do not let a salesperson skip the sheet. Do not treat bacteria or nitrate problems with a manganese filter.

Bottom line

Manganese in Wisconsin wells can stain black-brown, and at 300 µg/L DHS changes drinking and food-prep advice. The glass can still look clear. Order a certified-lab manganese test from the Wisconsin inventory. Compare µg/L to DNR/DHS 300 µg/L and EPA’s 50 µg/L SMCL — two different lines, neither a private-well kitchen-tap statute. Treatment class comes after the sheet. Iron often travels with it. Bacteria and nitrate still go to the health department.

Updated 2026-10-03.