The water program of Pennsylvania's land-grant extension, with signed articles on wells, springs, cisterns, and testing.
The testing guides tell a well owner what to test, how often, and how to read the lab report, and the numbers match EPA where we checked them. Articles carry named authors and revision dates, and many are available in Spanish. The lead author of the testing series is listed as former staff, and the university sells its own test kit and short paid courses alongside the free articles.
Best for Private well and spring owners deciding what to test
Free, with paid options
Start here: extension.psu.edu/testing-your-drinking-water
The extension program behind most of the published guidance on sizing, building, and maintaining residential rainwater systems in the United States.
Catchment yield, first-flush sizing, tank materials, and in-home use are covered with the design detail a reader needs before buying a tank. The site has been static since the mid-2010s and its treatment manual is a 2007 Texas state document, so take the design guidance from here and the treatment numbers from EPA and CDC.
Best for Designing a rain barrel or cistern system that actually yields what you expect
Free
Start here: rainwaterharvesting.tamu.edu/in-home-use
Minnesota's land-grant extension pages on private wells, well testing, and what to do after a flood, written by named educators.
Clear tables of what each contaminant means for a household and when to act, with every limit matching EPA where we checked. Written for Minnesota, but well basics travel. The drinking water pages were last reviewed in 2021 and 2022; the numbers still match current federal limits, and the lead limit tightens in 2027.
Best for Well owners outside the Northeast who want a second extension voice
Free
Virginia Tech's extension program that runs county well-water testing clinics and explains the results in plain terms.
The FAQ answers the questions a well owner actually has, from why the water smells to what a coliform hit means, and the numbers match or run stricter than EPA where we checked. Clinics run across Virginia through the year with a cost-recovery test kit; readers elsewhere get the same explanations free. Shock chlorination is referred to a licensed driller rather than given as a recipe.
Best for Understanding a well test result in plain language
Free, with paid options
Start here: wellwater.bse.vt.edu/faq.php
Well owner education from the National Ground Water Association, supported by an EPA-funded private well program.
A staffed hotline, a free printable maintenance checklist, and plain guidance on annual testing, written for people who own a well rather than for the trade. It is published by the drillers' trade association, so the contractor finder and the loan offer serve its members; the educational pages do not push either.
Best for Seasonal well maintenance and knowing when to call a contractor
Free
Start here: wellowner.org/resources/water-quality/water-testing