How To Chlorinate Your Well

So, you’ve got a well. Congratulations, you’re basically a medieval baron with plumbing. But every so often, your underground aquifer starts acting funky—like, “is that a dead mouse in the faucet?” funky. That’s when you need to chlorinate the thing, or as I call it, giving your well a spa day with bleach.

First, let’s get one thing straight: you are not trying to make your water taste like a public swimming pool. You’re just killing bacteria, viruses, and whatever slime monster has been partying in your aquifer. A shocking fact: one study found that up to 40% of private wells have coliform bacteria. Yes, that is poo-adjacent. So, yeah, we’re doing this.

Gather Your Weapons

You’ll need unscented household bleach—the cheap, clear kind. No “lemon fresh” or “ocean breeze.” Your well doesn’t care about aromatherapy. Also grab a garden hose, a five-gallon bucket, and the courage of a knight facing a dragon. Oh, and rubber gloves. Because bleach on skin feels like betrayal.

Here’s a surprising fact: bleach evaporates potency over time. That bottle in your laundry room from 2019? It’s basically fancy water. Go buy fresh stuff. The math is simple: if it smells like a hospital, it’s good.

Pump the Brakes—and the Water

Turn off your pump, or at least disconnect power to it. You don’t want to get electrocuted while holding bleach—that’s a party trick nobody invites you back for. Now, remove the well cap. If it’s rusted stuck, congratulate yourself on being strong, then hacksaw it off like a barbarian.

Pour your bleach directly into the well. How much? For a standard six-inch well, use three quarts of bleach per 100 feet of water depth. If your well is 200 feet deep, that’s a gallon and a half. Yes, we are doing elementary school math with poison. Write it down. Double-check. We don’t want your house to smell like a hazmat site.

The Circular Samba

Attach your garden hose to an outdoor spigot, drop it into the well, and turn on the water. Let it run for at least 15 minutes. This recirculates the bleach through the entire system—pipes, tank, and that weird guest bathroom nobody uses. Your goal is to give the whole house a colonic. The water will start to smell like a motel pool.

How to Chlorinate a Well (with Pictures) - wikiHow

Now, go inside and open every faucet—hot and cold—one by one. Let them run until you smell bleach at each tap. This is the “chemical victory lap.” Don’t forget the outdoor spigots, the washing machine, and that hose bib where your dog drinks. Your dog will get cranky, but your dog also licks unspeakable things, so take a number, Fido.

Wait. Just… Wait.

Turn everything off and let the bleach sit in the pipes for 12 to 24 hours. This is not a suggestion—sleep on it. The chlorine needs time to murder every microbe in existence. During this time, do not drink the water. Do not shower in it unless you want to emerge looking like a peeled shrimp. And definitely don’t rinse your contact lenses. That is how evolution weeds people out.

Surprising fact: chlorine is more effective at higher pH levels. If your well water is acidic (below pH 6), the chlorine fizzles out like a firework in a rainstorm. So if you’re fancy, test your pH first. Most people skip this and blame the bleach. Don’t be most people.

The Big Flush

After the wait, connect your garden hose again to the outdoor spigot and run it away from your house—into a ditch, a gravel patch, literally anywhere but your neighbor’s prize petunias. Let it run for an hour or until the chlorine smell is gone. Then go inside and flush every faucet again, repeating the process. This can take two hours or two days depending on how stubborn your well is. Welcome to the world of private water, where you are the city engineer and the janitor.

How to Chlorinate a Well (with Pictures) - wikiHow

Test the water. You can buy a test kit at a hardware store—it’s basically a pregnancy test for bacteria. If it’s still positive, repeat the process. Don’t panic. Wells are like teenage children—they don’t always obey the first time.

The Aftermath

Once the test comes back clear, flush again. Seriously, your water might taste like a swimming pool for a week. Boil it for pasta or buy bottled water. And remember: you just nuked your entire water system. It’s sterile now. You are basically a hand sanitizer brand ambassador.

One last shocking fact: many wells only need chlorination once a year—unless you have a flood, a dead animal nearby, or a houseguest who insists on “testing” the well water with their mouth. So set a reminder. Or don’t. Either way, your well knows now that you’re in charge. And it’s properly terrified.

Go ahead, take a shower. You’ve earned it. Just maybe open a window first.