With more than 30 years’ experience in the residential and commercial water treatment space, Mark Nelson is a Class 1 Drinking-Water Operator and a CBWA (Canadian Bottled Water Association) Certified Plant Operator. As founder and president of Nelson Water in Ottawa, Mark focuses on dealing with challenging water treatment system designs for problem water. He also heads the largest water bottling plant in the city of Ottawa with a delivery network throughout the Valley.
Bacteria is common in private well water, and it can cause a host of negative health effects, from nausea to diarrhea and worse. So, it’s important to test the well water regularly to ensure that you know which contaminants are present. Annual water testing is an absolute must because the makeup of water can change quickly due to a wide variety of environmental conditions. The most effective disinfection approach for a private well is chlorination. This is known as “shocking” the well, and it’s a tried and tested way to remove E-coli or coliform bacteria. In this article, we will take a closer look at this process to help you make informed choices.
A Brief Primer
It’s important to understand that shocking a well involves a little more than pouring a bucket of bleach into the well. There is a clear chlorination process to follow to ensure that there is sufficient bleach cleaning power to remove the bacteria. As this happens, you need to protect the rest of the water systems from potential damage.
Another consideration is that well water chlorination is extremely effective when you want to eliminate bacterial contamination. But, this is a one shot deal, the bacteria will be gone, and yet the underlying cause remains. So, if you are experiencing recurring contamination problems, the source must be identified. This could be a lack of proper maintenance, a well construction issue, a poor well location, and more.
Always remember that shocking the well is a temporary fix until you deal with the core problems. The process can be repeated regularly, and the process can be carried out by most homeowners with some preparation.
How Do I Disinfect My Private Well?
This is a common question; a DIY approach can be effective, but there is a process to follow, and some advanced planning is required. If you have bacteria in your well, it’s probably E.coli or some type of coliform. To make an accurate assessment, it’s a good idea to invest in annual laboratory water testing for your well. The DIY approach that we will detail here will remove E.coli and coliform bacteria, and the process can be repeated as needed.
Gather the Supplies
Locate the wellhead, get a bucket, some unscented bleach, rubber gloves, a garden hose, and chlorine test strips. The hose should be connected to an outside hose bib, and it needs to be long enough to reach the well. Always wear gloves to protect your hands from the bacteria as you work through the rest of this process.
Make Preparations
Next, go into the house and place the water softener into bypass mode to protect the resin media tank. All back washable filters should be bypassed, including sediment, sulfur, and iron filters. If you have cartridge water filters, these should be removed and set aside in a safe place until you’re done. There is no need to remove the UV purification light if you have one installed, and it can stay on throughout this process. Now it’s time to remove the wellhead cap bolts, but take care; there is an electrical connection in place. Once the bolts are removed, remove the wellhead and keep the bolts in a safe place.
Mixing the Bleach
Now it’s time to mix the bleach with water to create a cleaning solution for the well. The volume of bleach that you use will vary depending on the specifications of your specific well. Let’s take a look at three examples and one default approach:
- A 6” casing requires 280mm of bleach per 50 feet of water.
- Dug wells with 36” casings need 1L of bleach per 5 feet of water.
If you’re unsure about the amount of bleach you need to add, you can add 2L of bleach to the well. This is imprecise, but it is a good standby, and it should get the job done. When you’ve decided how much bleach to use, add that volume to around three gallons of clean water in the bucket and mix it thoroughly.
Pouring the Bleach Solution
Pour the solution into the well, take the connected hose and run the water back into the well to thoroughly circulate the chrome solution. Continue this process for at least one minute, and running the water for over two minutes is ideal. When you’re finished, shut off the hose and go indoors to run the cold faucet that’s at the furthest far point from where the water enters the home. Run the water until you can smell the chlorine to check that the cleaning worked, and this can be confirmed with the test strips. From this point, you can work your way back into the home to check other faucets and plumbing fixtures.
Checking the System
Start by flushing the toilet to move the water through the waste system. Then run the shower and/or tub faucets and check the condition of the water with the test strips. Only test the cold water at this stage, work your way back to the pressure tank area and then repeat the chlorination procedure discussed earlier. When the bleach solution has been added, repeat this entire process with hot water too. Again, start with the hot water faucet furthest away from where the water comes into the home and work back.
Washing the Well Casing
Take the hose and run the water into the well to clean the well casing surface. When you’re done, shut off the water and leave the well to sit overnight to give the well time to settle. If you’re in a hurry, you can continue the process after four hours, but longer is better. When you’re ready, hook up the hose again and run the water onto a hard flat surface such as the driveway. Don’t run the chlorine enriched water onto grass that you care about because it can kill the grass and other plants. You may be surprised at the discoloration in the water, but this is normal, and it’s especially noticeable if you have high concentrations of iron in your well water.
If you’re unsure about this process or you would prefer to hire a professional to disinfect your well, contact your local water treatment specialist today.