Last updated 2026-10-21.
Information only
Water Filtration Assistant explains publicly available water quality information and water treatment products. It is general information, not medical, legal or engineering advice, and it is not a substitute for a test of your own water by a certified laboratory.
About the water data
- Utility results are system-wide figures from each district's annual report, measured where water enters the system. Water at your tap can differ: your home's pipes and fixtures can add lead or copper.
- Reports cover a past year. Conditions may have changed since.
- We copy numbers carefully and link each one to its source, but mistakes are possible. The district's own report is the official record. Your water bill names the district that serves you.
Affiliate disclosure
Some links on this site are affiliate links. If you buy through them, we may earn a commission at no extra cost to you. Commissions never affect which products we show or their order: products are ranked by certified removal first.
Products
Product details come from makers' pages, spec sheets and certifier listings, and prices change. Check the details with the seller before you buy. Install treatment equipment according to the maker's instructions and local plumbing codes; some installations require a licensed plumber.
No warranty
The site is provided "as is", without warranties of any kind. To the extent the law allows, Water Filtration Assistant is not liable for losses arising from use of the site or of products you buy from third parties.
Third-party sites
Links to water districts, agencies, retailers and makers go to sites we don't control. Their terms and policies apply there.
Governing law
These terms are governed by the laws of the State of California.