PF PFAS Decision Engine
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Source policy

The project ranks sources before it ranks products and keeps that order visible.

Direct official evidence sits at the top. Certification directories and vendor records only open after the household path, benchmark context, and source ownership are already anchored.

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Verification ledger

Verification stays attached to the route.

Last verified 2026-03-20 / Source discipline

Verification details
Editorial owner
gabi Editorial Team
No external reviewer claim is made on this build.
Methodology owner
gabi Water Evidence Team
Read methodology for source handling and route logic.
Scope
Source discipline
Action-first, not safe or unsafe and not a health diagnosis.
Tracked sources
243
Registry-backed source documents.
State routes
10
State guidance seeds using official agency routes.
Seeded dossiers
83
Public-water and product records currently rendered.
Guides
23
Search-intent pages tied back to the same source ladder.
Trust tiers

Trust tiers

Higher tiers constrain the decision posture. Lower tiers can add commercial or operational context, but they cannot override route evidence.

Tier 1

Federal rule and program sources

Federal agencies for rule status, program context, and high-level filter guidance.

Tier 2

State and utility evidence

State agencies and utility records for direct route-specific evidence.

Tier 3

Certification directories

Certification directories and listing systems.

Tier 4

Vendor records

Vendor pages for price, replacement cadence, and official model detail.

Tier 1 examples

Federal source examples

Tier 1 / Agency for Toxic Substances and Disease Registry
PFAS Information for Clinicians – 2024
Tier 1 / Agency for Toxic Substances and Disease Registry
Testing for PFAS
Tier 1 / U.S. Environmental Protection Agency
CCR Information for Consumers
Tier 1 / U.S. Environmental Protection Agency
Identifying Drinking Water Filters Certified to Reduce PFAS
Tier 1 / U.S. Environmental Protection Agency
EPA Announces It Will Keep Maximum Contaminant Levels for PFOA, PFOS
Tier 1 / U.S. Environmental Protection Agency
Per- and Polyfluoroalkyl Substances (PFAS) NPDWR Implementation
Tier 1 / U.S. Environmental Protection Agency
PFAS in Private Wells
Tier 1 / U.S. Environmental Protection Agency
Per- and Polyfluoroalkyl Substances (PFAS)
Tier 2 examples

State and utility source examples

Tier 2 / Carolina Water Service of North Carolina
Annual Water Quality Report 2024 Abington CCR 002
Tier 2 / Carolina Water Service of North Carolina
PFAS Report 2023 Abington 002
Tier 2 / Alaska Department of Environmental Conservation
Monitoring Summary for College Utilities Corporation
Tier 2 / Alaska Department of Environmental Conservation
DWW - Water System Facility Detail
Tier 2 / College & Golden Heart Utilities
College & Golden Heart Utilities | Home
Tier 2 / College & Golden Heart Utilities
Water Safety | Water Quality Reports
Tier 2 / Utilities, Inc. of Georgia
Annual Water Quality Report 2024 Alpine Terrace CCR 742
Tier 2 / Utilities, Inc. of Georgia
PFAS Results 2023 Alpine Terrace 742
Commercial unlock rules

Source quality controls what the product layer may say.

A lower-tier source may add

  • Price
  • Replacement cadence
  • Exact model detail
  • Merchant destination

A lower-tier source may not add

  • A household risk grade
  • A compliance finding
  • A whole-house default
  • A reason to ignore missing direct evidence
Editorial guardrails

The trust layer is built from limits as much as from links.

  • No safe or unsafe labels are generated from indirect hints.
  • No anonymous reviewer theater is used to make the route sound more certain than the evidence allows.
  • No product page is allowed to outrun the public-water or private-well evidence path.
  • No whole-house suggestion is treated as a default answer to an ingestion-focused problem.
  • No vendor record can override a direct utility record, state guide, or official benchmark source.