Tier 1: official sources
These are preferred whenever available: utility water quality reports, Consumer Confidence Reports, EPA SDWIS/ECHO resources, state environmental agencies, local water departments, and USGS references.
Tier 2: official local context
Utility service-area pages, source-water pages, city water department pages, annual reports, and public infrastructure documents can support a profile when they explain local provider context.
Tier 3: credible secondary sources
Secondary sources may be used cautiously when official sources do not provide a specific field, especially water hardness. These should be labeled clearly and not treated as equal to direct utility data.
Sources we avoid for core facts
Unsourced blogs, anonymous forums, generic affiliate pages, and AI-generated summaries should not drive core profile facts. They may help identify questions people ask, but not final page claims.