A private well makes you your own water utility. Here is how to test, treat and protect the water your family drinks.
You are the water utility now
Public water systems are tested and treated by professionals every day. A private well is not. The EPA puts the responsibility plainly on the owner, and that responsibility grows on an estate that may have to run on its own water for months. Our guide to water independence covers sources; this guide covers making that water safe.
Test first, then treat
The EPA recommends testing a private well every year for total coliform bacteria, nitrates, total dissolved solids and pH, and more often in homes with infants, older adults or pregnant or nursing women. Test right away after flooding, nearby construction or well repairs, or any change in taste, odor or color. Add tests for what is nearby: pesticides and nitrate near agriculture, fuel compounds near tanks, radon where it occurs. Use a laboratory certified for drinking water.
The test results decide the treatment train. There is no single filter that does everything.
A typical treatment train
- Sediment filtration removes sand and silt. It protects everything downstream, and it matters for disinfection: the EPA notes that disinfection works less well in cloudy water.
- Carbon filtration improves taste and odor and, in certified units, reduces specific contaminants. NSF/ANSI 42 covers taste and odor; NSF/ANSI 53 covers health-related contaminants such as lead, cysts and certain organic chemicals.
- Ultraviolet disinfection inactivates bacteria, viruses and cysts without chemicals. A UV system certified to NSF/ANSI 55 Class A is designed for primary disinfection of water that is otherwise clear.
- Reverse osmosis, certified to NSF/ANSI 58, reduces dissolved contaminants such as arsenic, nitrate, fluoride and dissolved solids. It is usually installed at the kitchen tap for drinking and cooking water.
Every stage depends on power and spare parts, so an off-grid estate stores replacement cartridges and UV lamps and puts treatment on protected circuits.
When power or equipment fails
Boiling is the oldest and most reliable backup. The CDC advises bringing clear water to a rolling boil for one minute, or three minutes above 6,500 feet. The EPA uses a lower threshold of 5,000 feet for the three-minute rule. Much of the Mountain West sits above both, so our estates plan for three minutes.
Unscented household bleach is the other backup. The EPA's emergency ratio is 8 drops of 6 percent bleach (or 6 drops of 8.25 percent) per gallon of clear water, doubled for cloudy or very cold water, stirred and left for 30 minutes. The water should have a slight chlorine smell; if not, repeat the dose and wait 15 minutes more.
Cisterns and shock chlorination
Stored water needs care too. The CDC describes disinfecting a cistern of treated water with about 3 cups of unscented bleach per 100 gallons, left for at least 12 hours before draining and refilling. Wells are shock-chlorinated after repairs, flooding or a positive bacteria test, then retested before the water is used for drinking. We include both procedures in every household manual.
Key takeaways
- Test a private well every year for coliform bacteria, nitrates, total dissolved solids and pH.
- Filter sediment before UV; UV only works on clear water.
- Use certified equipment: NSF/ANSI 55 for UV, 53 for health contaminants, 58 for reverse osmosis.
- At high elevation, boil water for three minutes.
- Keep unscented bleach and a printed dosing chart for emergencies.
This guide is general information to help you plan. It is not engineering, legal or water-rights advice, and requirements vary by state and county. Every Styrkholm project is designed by licensed professionals for the specific site.