The Standards for Residential Water · HWS-2026

Every standard for a home’s water. One authority.

Plumbing, water heating, treatment, fixtures, drains, efficiency and code. We don’t invent the standards — we bring together the ones that already govern a home’s water system and set the bar above the legal minimum.

Read the standards Partner with us

Homeowner? Request a Home Water Review →

Who we work with

ContractorsPlumbing, water heating and treatment professionals carry the mark. Lenders & financingDocumented scope and verified installs behind every project you fund. Insurance & home warrantyA documented view of a home’s water system, across eight domains. Property, builders & real estateRecords and certificates for portfolios, new builds and transactions. HomeownersA Home Water Review and a Water Record that stays with the house.

Home water programs

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For homeowners

Start with a Home Water Review.

Your plumbing, water heating, fixtures, drains and water quality reviewed against the standards. Your home goes on the record, and every improvement raises it.

Already on record? Log in to your Water Record →

Request received.A participating provider will text you to confirm a time. After your review, your home goes on the record.

From the meter to the drain

Eight domains. Every standard in one place.

Each domain gathers the existing standards that apply, what the law requires, and the higher bar a home should meet.

01Source & service lineWhere the water comes from, and the pipe that carries it from the main to the house.02Whole-home treatmentWater treatment where the supply enters the home, serving every tap, shower and appliance.03Drinking water at the tapThe water the household drinks and cooks with.04Supply pipesEvery pressurized water line inside the home, from the meter to each fixture.05Water heatingThe system that stores or heats water, and how that water reaches people safely.06FixturesFaucets, showerheads, toilets and the valves that serve them.07Drains & sewerDrain, waste and vent lines, and the sewer lateral from the house to the public main.08Pressure & protectionWater pressure, backflow into the supply, and leaks.

Localized, nationally based

National floor. State rules. Your address.

NationalThe floor everywhere in the U.S.

EPA drinking water limits and health goals, the federal lead-free law, DOE efficiency standards, WaterSense and ENERGY STAR, and NSF/ANSI product certification.

StateWhat your state adds on top

State drinking water standards and health goals, appliance and fixture efficiency rules, and the plumbing code the state adopts — California, for example, adopts the UPC as the California Plumbing Code.

LocalWhat applies at your address

Your city or county’s code adoption and amendments, your utility’s annual water report, and the local cross-connection rules.

The bar rises

Every edition raises the bar or holds it. None lowers it.

When the law catches up to the standard, the standard moves ahead. Homes are verified to the edition in effect and can re-verify to any later one.

How editions work

Two levels

Reviewed, then Verified.

Know yourWATERHome Water Review™

Reviewed

A 15-minute Home Water Review at your kitchen table. Your home goes on the record.

Your utility’s report explained against legal limits and health goals
Your home’s water setup reviewed in person

Protect yourHOMEHome Water Standards™

Verified

A review, then a water improvement installed by a licensed contractor. Your certificate shows every domain improved — and stays with the house.

Improvements tracked across all 8 domains of the standard
A certificate buyers, insurers and agents can check

Have a certificate?

Check it in seconds.

Enter the certificate ID. Only that record’s status and domains are shown — never a list, never an address.

Contractors, lenders, insurers & B2B

One standard. Every partner.

Contractors license the Home Water Standards™ mark; lenders, insurers and property businesses work from the same documented record. Same audit fee whether you pass or fail — that’s why it means something.

Contractors & partners

Every home starts with a review. Every improvement raises the record.

Request a Home Water Review

The standards · HWS-2026 edition

Home Water Standards™. From the meter to the drain.

Eight domains. For each: the existing standards that apply, what the law requires where the home is, and the higher bar a home should meet. Codes vary by jurisdiction; the code adopted at the home’s address always controls.

Why “Standards”

No new rulebook. The ones that already exist, together.

Residential water is governed by dozens of standards — EPA drinking water rules, NSF/ANSI product certifications, the plumbing codes, DOE efficiency rules, WaterSense. Each covers one piece. Home Water Standards™ brings them together and organizes them by what they do for the home, so every bar traces back to a published standard.

NationalThe floor everywhere in the U.S.

EPA drinking water limits and health goals, the federal lead-free law, DOE efficiency standards, WaterSense and ENERGY STAR, and NSF/ANSI product certification.

StateWhat your state adds on top

State drinking water standards and health goals, appliance and fixture efficiency rules, and the plumbing code the state adopts — California, for example, adopts the UPC as the California Plumbing Code.

LocalWhat applies at your address

Your city or county’s code adoption and amendments, your utility’s annual water report, and the local cross-connection rules.

Domain 01

Source & service line

Where the water comes from, and the pipe that carries it from the main to the house.

Legal baseline

The utility must meet federal and state legal limits (MCLs) and publish an annual water quality report. Utilities must inventory service lines and replace lead lines under the 2024 Lead and Copper Rule Improvements.

Home Water Standards · HWS-2026

The home’s water report is reviewed against health goals — EPA maximum contaminant level goals, and state public health goals where set. The customer-side service line material is identified, and it is not lead or galvanized steel.

References Safe Drinking Water Act · EPA MCLs & MCLGs · Lead and Copper Rule Improvements (2024) · State drinking water standards (e.g. California public health goals)

Domain 02

Whole-home treatment

Water treatment where the supply enters the home, serving every tap, shower and appliance.

Legal baseline

Not required by federal, state or plumbing code.

Home Water Standards · HWS-2026

Treatment matched to the home’s measured water, using equipment certified to the applicable NSF/ANSI standard for its claims, and serviced on the manufacturer’s schedule.

References NSF/ANSI 42 (aesthetic effects) · NSF/ANSI 44 (softeners) · NSF/ANSI 55 (UV) · NSF/ANSI 401 (emerging compounds)

Domain 03

Drinking water at the tap

The water the household drinks and cooks with.

Legal baseline

Not required. The legal limit ends at the utility’s system; nothing governs the glass.

Home Water Standards · HWS-2026

A reverse osmosis or equivalent point-of-use system at the drinking tap, certified to NSF/ANSI 58 (and NSF/ANSI 53 for any health-effect claims), with filters and membranes changed on schedule.

References NSF/ANSI 58 (reverse osmosis) · NSF/ANSI 53 (health effects) · NSF/ANSI 401

Domain 04

Supply pipes

Every pressurized water line inside the home, from the meter to each fixture.

Legal baseline

Pipes, fittings and fixtures sold for drinking water must be lead-free: no more than 0.25% weighted-average lead. Materials must be approved under the plumbing code adopted where the home is.

Home Water Standards · HWS-2026

No lead or galvanized steel supply lines anywhere in the home. Copper or PEX throughout, with every component certified for drinking-water contact.

References SDWA §1417 · Reduction of Lead in Drinking Water Act · NSF/ANSI/CAN 61 · NSF/ANSI 372 · ASTM B88 (copper) · ASTM F876/F877 (PEX) · UPC / IPC

Domain 05

Water heating

The system that stores or heats water, and how that water reaches people safely.

Legal baseline

Federal minimum efficiency (DOE Uniform Energy Factor) and a temperature-and-pressure relief valve. States add their own rules — California, for example, requires seismic strapping.

Home Water Standards · HWS-2026

Tankless or ENERGY STAR® high-efficiency water heating, scald protection at bathing fixtures, the unit within its rated service life, and scale managed on schedule.

References DOE water heater efficiency standards · ENERGY STAR · ANSI Z21.22 (relief valves) · ASSE 1016 / 1070 (scald protection) · UPC / IPC

Domain 06

Fixtures

Faucets, showerheads, toilets and the valves that serve them.

Legal baseline

Federal maximum flow: toilets 1.6 gallons per flush, showerheads 2.5 gallons per minute. Some states set stricter limits — California: toilets 1.28 gpf, showerheads 1.8 gpm, bathroom faucets 1.2 gpm.

Home Water Standards · HWS-2026

WaterSense®-labeled toilets, showerheads and bathroom faucets, and lead-free fixtures certified for drinking-water contact.

References Energy Policy Act of 1992 · EPA WaterSense · California Title 20 · NSF/ANSI/CAN 61 · NSF/ANSI 372

Domain 07

Drains & sewer

Drain, waste and vent lines, and the sewer lateral from the house to the public main.

Legal baseline

Drain, waste and vent systems built to the adopted plumbing code. In many jurisdictions the property owner maintains the sewer lateral all the way to the main.

Home Water Standards · HWS-2026

Drain lines in sound ABS or PVC — no failing cast iron or Orangeburg pipe — an accessible cleanout, and a camera-inspected sewer lateral.

References UPC / IPC drainage requirements · ASTM D2661 (ABS) · ASTM D2665 (PVC)

Domain 08

Pressure & protection

Water pressure, backflow into the supply, and leaks.

Legal baseline

A pressure-reducing valve is required where street pressure exceeds 80 psi. Backflow protection follows the local cross-connection control program.

Home Water Standards · HWS-2026

Pressure regulated between 40 and 80 psi, hose bibs protected against backflow, and automatic leak detection with shutoff.

References UPC 608.2 · IPC 604.8 · Local cross-connection control programs

Editions

The bar only rises.

Editions are reviewed every year against changes in federal and state standards. An edition may raise the bar in any domain; none may lower it. When a legal minimum rises to meet the standard, the standard is raised above it. A home is verified to the edition in effect on its verification date and may re-verify to any later edition.

Request a Home Water Review

Definitions

The language of residential water.

The terms this standard is built on, in plain English.

Action level: A level that, if exceeded in enough homes tested, requires a utility to take specific steps. Used for lead and copper instead of a legal limit.
Backflow: Water flowing backward from a home or hose into the drinking water supply. Prevented with backflow devices and vacuum breakers.
Customer-side service line: The part of the service line on the property owner’s side of the meter or connection point. Usually the owner’s responsibility.
Domain: One of the eight areas of a home’s water system the Home Water Standards covers, from the service line to the drain.
Edition: A dated version of the Home Water Standards. Each edition may raise the bar in a domain; none may lower it.
Galvanized pipe: Zinc-coated steel pipe common in older homes. It corrodes from the inside and can hold lead picked up from upstream.
Health goal: The level of a contaminant with no known or expected risk to health. Federally, the EPA’s MCLG; some states set their own public health goals. Not enforceable.
Home Water Review: A review of a home’s water: the utility’s report against legal limits and health goals, and the home’s water system in person. Every home on record has had one.
Legal limit: The highest level of a contaminant a public water system may deliver. Federally, the EPA’s maximum contaminant level (MCL). Enforceable.
Point-of-use: Treatment at a single tap, usually the kitchen drinking tap, as opposed to the whole home.
Pressure-reducing valve: A valve that lowers street pressure entering the home. Required by plumbing code where pressure exceeds 80 psi.
Property line: Where responsibility for water changes hands: the public water system answers for water up to it; the owner answers for everything past it.
Reverse osmosis: A point-of-use treatment that pushes water through a fine membrane to remove dissolved contaminants. Certified under NSF/ANSI 58.
Reviewed: A home that has completed a Home Water Review. The first level of the record.
Service line: The pipe that carries water from the public main to the home.
Verified: A reviewed home that then had a water improvement installed, confirmed from the installation record.
Water improvement: Work that raises a home toward the standard in one or more domains — for example, whole-home treatment, reverse osmosis, a repipe, or a new water heater.
Water Record: The private record of a home’s water system under the Home Water Standards. Its status and verified domains can be checked by certificate ID.
WaterSense: An EPA label for fixtures that use at least 20% less water than the federal standard and meet performance criteria.
Whole-home treatment: Treatment where water enters the home, so every tap, shower and appliance receives treated water.

For contractors

Carry the mark. Earn the recommendation.

Plumbers, water treatment dealers and manufacturers can license the Home Water Standards™ mark. Homeowners, agents and insurers check it — and every install you record becomes a certificate the homeowner keeps.

Solo contractor

One license, one truck

$69 / month

License to display the mark
Listed as a member on VerifiedStandards.com
Issue verified install records at $25 each
Onboarding audit and annual re-audit

Multi-crew company

Every crew under the mark

$199 / month

Everything in Solo, for all crews
Company-level member profile
Priority audit scheduling
Record volume reporting

Manufacturer

Products that meet the bar

$5,000 / year

Product listing by domain
Mapped to the NSF/ANSI standard each product is certified to
Use of the mark on qualifying products

Founding pricing. Membership fees pay for the audit, not the result.

The rules that make the mark worth carrying

The fee is the same whether you pass or fail the audit.
Members who fall below the standard are removed, and removals are published.
Members disclose any sponsor or sales relationship before a review begins.
A member may never present the mark as a government or third-party certification.

Application received.We’ll verify your license and schedule your onboarding audit.

Partners

Built for everyone who stands behind a home’s water.

Contractors, lenders, insurers and property businesses all make decisions about the same pipes, heaters and fixtures. Home Water Standards™ gives them one set of standards and one documented record to work from.

Contractors

Carry the mark

Plumbers, water heating installers and treatment dealers license the Home Water Standards™ mark and issue verified install records homeowners keep.

Contractor membership →

Lenders & financing

Fund documented work

Projects scoped to published standards, completed by audited members, and confirmed by a verified install record. Financing partners can be offered to homeowners at the point of review.

Become a financing partner →

Insurance & home warranty

See the system, not just the policy

A documented view of a home’s water system across eight domains — supply pipes, water heater, pressure, leak protection and more — shared only with the homeowner’s consent.

Talk about data & programs →

Property, builders & real estate

Records that travel with the home

Property managers and HOAs track portfolios to the standards. Builders deliver homes verified from day one. Agents and inspectors hand buyers a certificate they can check.

Start a program →

Partner inquiry

Let’s build it together.

Tell us who you are and what you’re looking for. Contractors can apply for membership directly.

How partnerships work

Standards are published and the same for every partner.
No partner can pay to change a score or a verification result.
Homeowner records are shared only with the homeowner’s consent.

Inquiry received.We’ll reply within two business days.

Verify a certificate

Check a Water Record.

Enter the ID printed on the home’s certificate. You’ll see its status and what was installed. No addresses, no owner details, no lists.

Members

Log in to your Water Record.

Use the email you gave at your review. We’ll send a one-time sign-in link — no password to remember.

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Records & requests.

ID	Address	Status	Improvement	Login email

Privacy

Your record is yours.

Never public

No list of homes is published anywhere.
Addresses, names and contact details are visible only to the homeowner and our admins.
A certificate check shows one record’s status and equipment — nothing else.
Never sold. Never shared without your permission.

Request received.We’ll confirm ownership and follow up.

Every standard for a home’s water. One authority.

Start with a Home Water Review.

Request a Home Water Review

Eight domains. Every standard in one place.

National floor. State rules. Your address.

Every edition raises the bar or holds it. None lowers it.

Reviewed, then Verified.

Check it in seconds.

One standard. Every partner.

Home Water Standards™. From the meter to the drain.

No new rulebook. The ones that already exist, together.

Source & service line

Whole-home treatment

Drinking water at the tap

Supply pipes

Water heating

Fixtures

Drains & sewer

Pressure & protection

The bar only rises.

The language of residential water.

Carry the mark. Earn the recommendation.

One license, one truck

Every crew under the mark

Products that meet the bar

Apply to carry the mark

Built for everyone who stands behind a home’s water.

Carry the mark

Fund documented work

See the system, not just the policy

Records that travel with the home

Let’s build it together.

Partner with Home Water Standards™

Check a Water Record.

Log in to your Water Record.

Welcome back.

Records & requests.

Edit record

Your record is yours.

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