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    Hydrology University

    Guide · Start with the problem

    Well water versus city water: who is responsible for testing

    Public systems are regulated and report annually. Private wells are the owner's responsibility.

    HU Editorial Team · Cites EPA, NSF/ANSI, and the sources linked below · Updated October 2026

    The problem

    Public water systems must test and publish a Consumer Confidence Report.

    Private wells are not covered by the Safe Drinking Water Act; owners decide what and when to test.

    What public data can and cannot say

    Can tell you

    • City customers can read their CCR and the ZIP report.

    Cannot tell you

    • There is no public dataset for an individual private well.
    Check your ZIP public-system report

    How to test

    • Well owners: test at least for bacteria and nitrate on the schedule your health department recommends.
    • City customers: start with the CCR, then test the tap for plumbing-related questions.

    System types compared

    • Sediment prefilter

      Point of entry

      Micron rating and housing size

      Reviews

    • Whole-house

      Point of entry

      Whether the seller lists the system for well water

      Reviews

    • Under-sink RO

      Point of use

      Pre-treatment needs and listed scope

      Reviews
    Check your ZIP

    Referred equipment

    Sources

    1. US EPA, Consumer Confidence Reports
    2. US EPA, Private drinking water wells

    FAQ

    Does the ZIP report cover my well?
    No. It covers public systems only. Private wells need their own test.

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