WaterAnswer.com

Water Quality Tools & Resources

This hub is designed around one workflow: Locate -> Validate -> Prioritize -> Treat.

Start with the task, not the product

  • I need to know what’s in my water: Use the ZIP/address lookup workflow.
  • I want a location-first drilldown: Use the state -> city -> system browser.
  • I have my utility report and need help reading it: Start with the CCR guide.
  • I want to validate product claims first: Use the NSF certification checker workflow.
  • I want contaminant-to-treatment mapping: Use the treatment matrix.
  • I already know the contaminant and need treatment: Use the filter decision guides.
  • I have a private well: Skip utility lookup and go straight to testing workflow.

July 1 deadline reminder

Public water systems in the US are required to deliver annual CCR reports by July 1. If your report is missing, check your utility site and EPA’s CCR directory first.

External resources worth bookmarking

Modular quick-reference cards

Hardness conversion

Grains per Gallon (gpg) mg/L as CaCO3 Category
0-1 0-17 Soft
1-3.5 17-60 Slightly hard
3.5-7 60-120 Moderately hard
7-10 120-180 Hard
10+ 180+ Very hard

Convert with: mg/L รท 17.1 = gpg

NSF standards

Standard What It Covers
NSF 42 Chlorine taste/odor, aesthetic issues
NSF 53 Lead, cysts, VOCs, health-effect contaminants
NSF 58 Reverse osmosis (PFAS, arsenic, nitrates, fluoride)
NSF 401 Emerging contaminants (pharmaceuticals, pesticides)
NSF 55 Class A UV disinfection, purification level
NSF 55 Class B UV disinfection, supplemental only
NSF 177 Shower filtration

A filter certified under one standard is not automatically certified under others.

Methodology-first trust notes

  • We prioritize primary sources: EPA rules, utility CCRs, and NSF certifications.
  • We separate legal compliance from health-target interpretation.
  • We annotate uncertainty when utility-level or address-level mappings are incomplete.
  • We publish review and ranking policy here: /review-policy

Start With These

Start Here

Water System Lookup and Contaminant Triage

ZIP-first and address-first workflow to identify likely utility context, then move to contaminant and treatment decisions.

Water Quality Browser

Browse from state to city to water system to contaminant before selecting tests or filters.

What Water Filter Do I Need?

Match your contaminant to the right NSF standard and filter type. The decision guide most filter sites skip.

NSF Certification Checker Workflow

Certification-first checklist to verify exact model claims before you buy.

Contaminant to Treatment Matrix

EPA treatability-inspired matrix mapping contaminants to practical household treatment options.

NSF Certification Standards Explained

NSF 42, 53, 58, 401, 55, what each covers and why the specific number matters when you're buying a filter.

EPA MCL vs. MCLG Explained

The legal limit and the health goal are different numbers. Why EWG standards differ from EPA limits.

What Is TDS in Water?

Total dissolved solids measures everything dissolved in your water. What a high reading means and what it doesn't.

 Well Water

How to Test Well Water

What to test for, how often, how to find a certified lab, and how to read the results.

Private Well Water Action Plan

CDC/EPA style trigger-based checklist for annual and event-based well testing.

How to Read Your Water Quality Report

Your utility sends a CCR every year. Here's what the numbers actually mean and where to find yours.

Frequently Asked Questions

What's the fastest way to look up my water system?
Start with ZIP code in the Water System Lookup tool, then confirm your utility name from your water bill or Consumer Confidence Report (CCR). ZIP and address matches are triage tools and may not reflect service boundary edge cases.
When do utilities publish Consumer Confidence Reports?
US public water systems must deliver the annual CCR by July 1 each year. If you did not receive one, check your utility website or use the EPA CCR directory.
How should I choose between EPA limits and stricter health benchmarks?
Use EPA limits to understand legal compliance and utility obligations. Use stricter health benchmarks to set your personal risk tolerance and treatment goals. They answer different questions and should be used together.
Where can I find a certified lab to test my water?
Use the EPA private wells resource hub and your state-certified lab list. For private wells, annual testing and event-based testing (after flooding, repairs, or smell/taste changes) are both important.