A private well can become a source of fresh water supply. Over time, however, it may become contaminated with bacteria and other harmful pathogens. Adding chlorine is an effective treatment against bacteria, as it kills them all. This process takes a day or two, so it's best to prepare for minimal water consumption during this time.
Method 1 of 3: Preparation
Step 1. Determine when to perform chlorine treatment
It is a good idea to purify the well at least once a year, preferably in the spring. Apart from this time, there are various other circumstances in which treatment becomes necessary:
- If you notice a change in the color, smell or taste of your drinking water, or if your annual test results show bacteria.
- If the well is new, if it has recently undergone repairs or if new pipes have been added.
- If it has been contaminated with other water that has infiltrated or if the water becomes muddy or cloudy after a rain.
Step 2. Get the necessary materials
obviously you will need chlorine to purify the well. You can use it in tablet or granule form, but it can be easier to use regular household bleach. The important thing is to buy an odorless variety. It may take up to 40 liters, depending on the size of the well.
Chlorine test kit:
It allows you to accurately measure the chlorine levels in the water, rather than simply relying on the smell. These kits are usually used for swimming pools and can be found at any pool and spa supply store. Make sure you get the OTO test in drops instead of paper strips, as these only indicate the ideal chlorine levels for swimming pools.
To recirculate the water in the well, you need a clean garden hose. Some sources recommend using a tube with a diameter of 1.25 cm, rather than the standard 1.5 cm one, but that is up to you. You should cut the end of the pipe at an acute angle.
Step 3. Calculate the volume of the well
To determine the amount of chlorine needed to properly disinfect the well you need to measure the volume of water it contains. To do this, multiply the depth of the well (in cm) by the liters of water per square meter.
- To determine the depth of the water in the well you need to measure the distance from the bottom to the waterline. You can do this by using a fishing line and a medium sized weight. The line remains taut until the weight touches the bottom; once reached, the thread goes limp. When this occurs, mark the point on the line with a piece of string or tape, extract it from the water and measure the length.
- Alternatively, you can contact the company that built the well, as they usually keep a record of all their projects.
- The number of liters per square meter is related to the diameter of the well and should be indicated on the documentation. Drilled wells usually have a diameter between 10 and 25 cm, while those drilled vary between 30 and 60. Once you know the diameter of the well, you can do an online search and find tables to calculate the liters.
- Now that you have the measurements for the water depth (in cm) and the amount of water per square meter (in liters / m), you can multiply these numbers to get the total volume of water. You must use 1.5 liters of bleach for every 400 liters of water, plus another 1.5 liters to treat the water in the house's plumbing.
Step 4. Plan to not use the well water for a minimum of 24 hours
The chlorination process takes time, usually 1 to 2 days. During this time you cannot take water for daily household activities, so it is important that you plan accordingly.
- During the chlorination process there will be more chlorine in the well than in a swimming pool, which makes it dangerous to consume the water. Also, if you use too much, the chlorine can end up in the septic tank, where it kills the bacteria needed to break down the waste.
- For these reasons, you will need to consume bottled water for drinking and cooking and not turn on sinks or showers. You should also try to use the toilet as little as possible.
Method 2 of 3: Chlorinate the Well
Step 1. Open the vent
Depending on the type of well, it may be necessary to open the vent tube to pour in the chlorine.
- The pipe should be on top of the well, it is usually about 15cm long and 1.25cm in diameter. Open the vent by unscrewing the tube from the gasket.
- Alternatively, it may be necessary to remove the cover from the top of the pit by unscrewing a few screws.
Step 2. Pour in the chlorine
Once you have access to the well, carefully pour in the right amount of chlorine, avoiding getting any electrical connections wet.
- Gloves, goggles, and an apron should be worn when handling undiluted chlorine.
- If you spill some on the skin, rinse immediately with clean water.
Step 3. Connect the hose
Attach the end to the nearest tap, then insert the other end (which you cut at an angle) into the hole left by the vent pipe or directly into the well.
If the pipe isn't long enough to reach the well, try joining some of them together
Step 4. Recirculate the water
Open the tap to maximum and let the water circulate for at least an hour.
- The water flowing from the tube pushes the water from the bottom of the well to rise to the surface, evenly distributing the chlorine.
- In this way all the bacteria present in the water come into contact with the chlorine and are killed.
Step 5. Test for chlorine
When the water has been circulating for at least an hour, you can check the amount of chlorine present. You can perform the test in two ways:
- Remove the hose from the vent and use the chlorine kit to check its presence in the water that comes out of the hose.
- Alternatively, you can turn on an outside faucet to see if you can detect the chlorine smell.
- If the chlorine test comes back negative or you don't smell chlorine in the water supply, keep recirculating the water for another 15 minutes, then retest.
Step 6. Rinse the walls of the well
Once the chlorine has been detected, reinsert the tube and run the water vigorously for 10-15 minutes all around the walls to wash any residual chlorine from the pump structure and pipes. Once this is done, remove the hose and replace the lid or reinsert the vent hose.
Step 7. Do the chlorine test inside
Enter the house and check for chlorine in every sink and shower in the bathroom and kitchen, using the kit or your sense of smell.
- Do not forget to test both taps, both the hot and cold water taps, and also remember to check any external taps until it detects the presence of chlorine.
- You should also flush each toilet once or twice.
Step 8. Wait 12 to 24 hours
Let the chlorine act in the water supply for a minimum of 12 hours, but preferably 24. During this time, do your best to consume as little water as possible.
Method 3 of 3: Remove the Chlorine
Step 1. Prepare as many hoses as possible
After 24 hours the water will be completely disinfected and you can start the chlorine removal process.
- To do this, connect as many hoses to outdoor taps as possible and tie the ends around a tree or fence about 1 meter above the ground. This makes it easier to monitor the water flow.
- Do not run the water near the septic or septic tank, as you do not have to expose these areas to chlorinated water.
Step 2. Run the water at maximum pressure
Open all the taps and let the water run as hard as possible. Try directing the flow into a ditch or some area that can contain water.
The important thing is that the ditch does not flow towards a stream or a pond, because the chlorinated water would kill fish, plants and other animals
Step 3. Test for chlorine
Periodically check the water coming out of the pipes to check for the presence of chlorine.
Use the kit for this purpose, as you cannot detect small amounts of chlorine by smell alone
Step 4. Do not leave the well running dry
While it may seem like a tedious task, it is important to monitor the flow of water at all times to ensure that the well does not run dry.
- If the well dries up, the pump can burn and its replacement can be very expensive. If the water pressure seems to drop, turn off the pump and wait an hour before running it again. In this way the well fills naturally.
- Stop the flow of water only when all traces of chlorine have been removed; this could take as little as two hours or more, depending on the well.