How we check listings

• Every listing comes from the program's own official page: a state lab, health department, extension office, or water utility.
• Each one shows the date we checked it. We recheck within 90 days.
• No program pays to be listed or to rank higher. Order is distance, then price.
• Limits on the results page come from the EPA, with the source linked.
• Found a mistake? Tell us and we recheck the official page.
• Download the data (CSV).

216 programs listed.