How To Chlorinate a Well – Step By Step Guide 2023

Last Updated on January 3, 2023 by Mattias

Chlorinating a well is essential to keep bacteria and other harmful things out of your well, but always remember to find the cause after you’re done with the chlorination.

In this guide, you will learn how to chlorinate a well by yourself, but always contact a professional if needed.

When Should You Chlorinate Your Well?

The United States Environmental Protection Agency recommends all well owners test their water yearly for coliform bacteria. 

well depth

Your well must be chlorinated when: 

  • Test results from a lab show presence of coliform bacteria are present. 
  • Surface or flood water gets into your well
  • You have a new well that has just been hooked up to your plumbing system. 
  • You’ve just repaired or replaced your well pump.
  • If you’ve installed: a new holding tank, pump, or pressure tank in your well system.
  • Signs of iron or sulfur bacteria, even if they don’t have a health threat, can give your well water a brown color and bad taste, and cause clogging in your pump and water system. 

Before you begin the well disinfection process, store enough water for at least 24 hours for household use, drinking, cooking, and flushing toilets. 

If you’re disinfection your well because of a positive test, you must use a safe source of bottled water for drinking and cooking during the disinfection process. 

Before you start disinfection your well, let all your neighboring well owners know that you’re going to disinfect it so they can monitor their system for any chlorine bleach smell.

Let your family know not to use the water during the disinfection of the well.

Read also: Pressure Switch For Well Pump Adjustment 101

How To Chlorinate a Well

Before starting the process, you need the following:

  • A 5-gallon bucket
  • Wrenches so you can remove the well cap
  • Clean hose
  • Small cup
  • Where to turn ON/OFF the well pump

Buy regular unscented detergent-free household bleach, which is needed to destroy the bacteria in the water.

Handle the bleach carefully by wearing protective gloves, glasses, and clothing. 

Determine how much bleach to add to your well water follow these instructions 

  • Find the depth of your well 
  • Diameter of your well casing 
  • Depth to water level 

These measurements should be listed on your well information report. If you don’t have a report, you can get additional information about your well here.

If the diameter isn’t listed in the report, simply measure it using a tape measure.

The water level may be measured manually in a large-diameter well using a tape measure. 

Manually measuring the depth in a small diameter well is not recommended because of the risk of getting tangled in well pump wires.

Use these measurements to find the depth of water in your well: 

Let’s say your well is 100 feet deep, and you must go down 16 feet until you hit the water table. That means 100 – 16 = 84 feet of water in the well. 

Diameter of well casing Chlorine bleach solution added per 3 feet of water in well  
2 inches2 tsp
4 inches8 tsp
5 inches4 tbsp
6 inches6 tbsp
8 inches11 tbsp
30 inches9 1/2 cups
36 inches13 1/2 cups

Let’s start by following these instructions, so you can measure the depth.

Read also: How Fast Does Well Water Replenish? An Easy Explanation

How To Chlorinate a Well: Instructions

1. Turn the power to your well pump OFF, and If you got a water softener, filter, or any purification equipment now, it’s time to bypass them. Some water softeners shouldn’t be chlorinated, so contact the manufacturer of your water softener before bypassing it.

Warning: Don’t use liquid bleach with a steel well casing since it can break loose accumulated corrosion and cause your pump to fail.

If you got a steel well casing, use granular chlorine instead. 

2. Remove the well cap but be careful because if your well cap has one large bolt in the center. Don’t try to remove it. 

Then you must call a licensed well constructor for the disinfection. This also applies if your well head is buried, shallow wells, or doesn’t follow the construction requirements. 

3. If you could remove the well cap try to measure the water depth in the well to determine how much bleach should be used. 

Warning: Well caps and seals are often regulated by local codes and the state. Ensure you’re following all applicable codes and laws if you’re opening your well. 

If you’re uncertain, don’t hesitate to contact any licensed well contractor, driller, or pump installer for help. 

It’s better to call for help and don’t do something wrong that can damage your well or other wells nearby. 

4. Pour the determined bleach into the bucket, then sanitize the upper portion of the well by pouring the solution into your well between the well casing and the crossbar. Try not to get any solutions on the wires since they could corrode. 

5. Connect your garden hose to your outside faucet and extend it about 4 feet into your well. 

6. Turn your pump ON and the outside faucet on. Let the water from the hose run for 20-25 minutes, distributing the solution in the system. 

7. Now turn your pump OFF and remove the hose. 

8. Put the well cap back. 

9. Now you can turn the power ON, once again. 

10. Now turn on each outdoor and indoor faucet. Let the cold water run until you can smell a chlorine/bleach smell.

Let the water run everywhere, like the shower, dishwasher, washing machine, and toilet. 

11. Turn off all faucets when a chlorine smell occurs.

12. Now wait 6 hours minimum but overnight is recommended, and use the stored water as drinking water if you’re thirsty.

13. After 12-24 hours – connect a hose to your outdoor faucet and let water run on the ground for 20-30 minutes. 

Therefore, the chlorine is flushed away from your water system. Keep the water away from:

  • Your drainage
  • Trees and plants
  • Streams or rivers
  • Lawns

When the time has passed, turn the outdoor water faucet OFF.

14. Let all indoor and outdoor faucets run for 3-5 minutes so the last solution is removed. 

15 . The last important step is to do one more water test to ensure you did a proper disinfection. If you still have bacterial contamination, iron, or sulfur, contact a professional for more help. The test should be done 2-3 weeks after the disinfection.

Read also: How To Prime a Well Pump – Step By Step

How To Disinfect Your Well Water – Shock Chlorination

How To Chlorinate a Well Summary

I hope you found this guide helpful.

As you discovered, it’s a pretty long process that must be done carefully, but it’s essential to do it when needed so you and your family can have clean water.

Always contact a professional if you’re uncertain about anything when chlorinating your well.