How Long Does it Take To Get Chlorine Out of Well Water


When it comes to ensuring the safety of your well water, shock chlorination is a common practice. This method involves introducing chlorinated water flowing into your well to eliminate harmful bacteria and contaminants. 

However, after the shock chlorination, many well owners wonder how long it takes for chlorine to leave their plumbing and when their water will be safe to drink again. In this article, we’ll delve into these questions and provide valuable insights on how long does it take to get chlorine out of well water.

How Long does it Take for Chlorine to Leave your Plumbing after Shock Chlorination?

How long does it take to get chlorine out of well water? The time it takes for chlorinated water to dissipate from your plumbing system can vary. Generally, chlorine bleach will naturally evaporate over time, but several factors influence how quickly it disappears.

These factors include the water temperature, the presence of organic matter, and the depth of your well.

Water Temperature

Warmer water tends to release chlorinated water faster. So, if you’re shocking your well during the summer, it may take less time for the chlorine to dissipate compared to doing it in the colder months.

Organic Matter

If your well water contains a lot of organic matter, such as leaves or algae, it may take longer for chlorine to neutralize these contaminants. In such cases, you may need to flush your plumbing system more thoroughly.

Well Depth

Deeper wells may require more time for the chlorine to reach the bottom, where it’s needed to disinfect the water. Therefore, it may take longer for chlorine to disappear from deeper wells.

When is Water Safe to Drink After Shock Chlorination?

After the shock chlorination process, it’s crucial to determine when your well water is safe for drinking. The safety of your water primarily depends on the concentration of chlorine remaining in the chlorinated water.

Chlorine is used to disinfect the water, but it can be harmful in high concentrations. Therefore, you should wait until chlorine levels drop to a safe and acceptable range before considering your water safe for consumption.

Typically, the recommended chlorine concentration range for safe drinking water is around 0.5 to 1.0 parts per million (ppm). This range ensures that harmful bacteria and contaminants have been effectively neutralized, but the water remains safe for human consumption.

When looking at how long does it take to get chlorine out of well water, you have to assess the chlorine levels in your well water accurately, you can use chlorine test strips. These kits are readily available at most hardware stores or online retailers and are easy to use.

Follow the instructions provided with the kit to test the chlorinated water’s chlorine smell concentration. Once the chlorine levels fall within the acceptable range, your water can be considered safe for drinking and cooking.

How to Know if Your Shock-Chlorinated Water is Safe to Drink

Ensuring the safety of your well water post-shock chlorination involves monitoring chlorine levels and verifying the absence of harmful bacteria. Here’s a step-by-step approach:

Chlorine Test Strips

As mentioned earlier, use chlorine test strips to check the concentrated chlorine solution in your water. Ensure that it falls within the recommended range of 0.5 to 1.0 ppm for safe drinking.

Bacterial Testing

While chlorinated water effectively kills many bacteria, it’s essential to confirm that harmful microorganisms have been eliminated. You can do this by having your water professionally tested for coliform bacteria.

If the test results come back negative for coliform, it indicates that the shock chlorination process has effectively disinfected your well.

Consult a Professional

If you have any doubts about the safety of your water, consider consulting a water quality expert or a local health department. They can provide guidance on water testing and safety standards specific to your region.

How to Know if Shock Chlorination Has Worked

To assess the effectiveness of your shock chlorination treatment, it’s essential to confirm that it has successfully eliminated harmful bacteria and contaminants. Here’s how to verify its success:

Water Testing

As mentioned in point 3, professional water testing for coliform bacteria is a reliable way to determine if the shock chlorination process has worked. Coliform bacteria are commonly used as indicators of water contamination because their presence suggests the possible presence of harmful pathogens.

Repeat Testing

In some cases, it may be necessary to conduct follow-up water testing to ensure that the bacteria have not returned after shock chlorination. This is especially important if you’ve experienced recurrent contamination issues in the past.

Observe Water Quality

 Pay attention to the taste, odor, and clarity of your drinking water. After successful shock chlorination, your well water should be clear, odorless, and free from any unusual tastes. Any persistent issues should be investigated further.

Remember that the effectiveness of shock chlorination depends on proper procedure and thorough flushing of your plumbing water system. If you have concerns about your water’s quality or the success of the shock chlorination process, consult with a water treatment professional for guidance and additional testing.

Regular maintenance and vigilant monitoring of your well water quality are essential for ensuring the long-term safety of your drinking water supply. 

Alternatives to Shock Chlorination

While shock chlorination is a commonly used method for disinfecting well water, there are alternative approaches that you can consider depending on your preferences and specific well conditions.

Maintain Your Well Properly

Proactive well maintenance can help prevent contamination and reduce the need for shock chlorination. Here’s how:

Regular Inspection: Periodically inspect your well for any visible signs of damage, like cracks or leaks. Address issues promptly to prevent contaminants from entering the well.

Sealing the Well: Ensure that your well is properly sealed to prevent surface water, contaminants, or pests from infiltrating the well casing.

Keep the Area Clean: Maintain a clean and well-maintained wellhead area. Remove debris, vegetation, and potential sources of contamination from the vicinity of the well.

Testing and Monitoring: Regularly test your well water for contaminants, especially if you notice changes in water quality. Early detection can help you address issues before they become severe.

Use a Continuous Disinfection Treatment System

Instead of periodic shock chlorination, you can opt for a continuous disinfection treatment system that provide ongoing protection for your well water:

Ultraviolet (UV) Disinfection: UV systems use ultraviolet light to kill bacteria, viruses, and other microorganisms without adding chemicals to your water. They are effective and require minimal maintenance.

Chlorine Injection: A chlorination water treatment system that injects a controlled amount of chlorine into your water supply can provide continuous disinfection. It’s important to monitor and adjust the chlorinated water levels as needed to maintain water quality within safe limits.

Ozonation: Ozone generators can be used to disinfect well water by producing ozone, a powerful oxidizing agent that destroys bacteria and contaminants. Ozone treatment is effective but may require professional installation and maintenance.

Consider a Chemical-Free Option

If you prefer not to use chemicals like chlorine, there are chemical-free treatment options to consider:

Reverse Osmosis (RO): RO systems use a semipermeable membrane to remove contaminants from water, including bacteria and chemicals. They are effective but may have higher upfront costs and require regular filter replacement.

Activated Carbon Filters: These filters are excellent at removing a wide range of contaminants, including chlorine, volatile organic compounds, and unpleasant tastes and odors. They provide chemical-free treatment but should be replaced periodically.


In conclusion, when looking how long does it take to get chlorine out of well water, maintaining the safety and quality of your well water is of utmost importance. Chlorination (shock) is a widely used method to disinfect well water, but it’s essential to wait until chlorine smell levels fall within the safe range before using the water for drinking and cooking.

Regular monitoring, well maintenance, and water testing are key to ensuring the ongoing safety of your water supply.

Additionally, alternative disinfection methods, such as continuous disinfection treatment systems and chemical-free options like RO and activated carbon filters, offer effective alternatives to chlorination (shock). Choosing the right method depends on your specific needs and preferences.


How often should I perform well maintenance?

Regular well maintenance should include inspections at least once a year. However, it’s essential to monitor your well’s condition and water quality continuously and address any issues promptly.

Are chemical-free treatment methods as effective as chlorination(shock)?

Chemical-free methods like UV, RO, and activated carbon filters can be just as effective as shock chlorination in removing contaminants from well water. The choice depends on your water quality and treatment goals.

Can I use multiple disinfection methods simultaneously?

Yes, you can combine disinfection methods if necessary. For instance, you can use a UV system for continuous disinfection and an activated carbon filter for improved taste and odor removal. Consult with a water treatment equipment professional for the best combination based on your water quality concerns. 

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