All About Water Treatment Systems: Chlorination (Chlorine)

Treating well water bacteria with chlorination

Treating well water bacteria with chlorination

Bacteria and springtime well flooding are common concerns for homeowners that use a water well. The typical course of action involves chlorination as a treatment. Shock chlorination uses a strong bleach solution which can kill most organisms on contact. Unfortunately, bleach can have unexpected consequences and can react with well components or other naturally occurring chemicals found in ground water.

Let's explore some frequently asked questions about chlorination and how it works to sanitize your well.

What exactly is water well chlorination?

Chlorination treatment consists of shocking your well with a high dose of chlorine to purify your water and kill any bacteria blooms that may occur as a result of natural processes, or events like flooding. Because the chlorination process can produce serious unintended consequences depending on other chemicals that may be present, it is best handled by a trained well water professional. 

Homeowners often are tempted to use ordinary household bleach for shock chlorination, much like treating an algae bloom in a swimming pool. They often use larger, more concentrated batches of chlorine, or perform chlorination more frequently than typically recommended. It's always best to consult with your well professional before attempting any do-it-yourself treatment.

What are the benefits and dangers of water well chlorination?

When properly administered, chlorine will kill any bacterial organisms present and sanitize your well. Unfortunately, chlorination can have side effects that may require additional types of treatment. For example, for homeowners in New England, naturally occurring arsenic may be present in soil and groundwater. Shock chlorination can cause serious issues where arsenic may be present in the environment. 

Shock chlorination can temporarily increase the concentration of metals present in groundwater. Elevated levels of lead, copper, zinc, iron, and arsenic have been measured in wells after chlorination. In some instances this can result in additional costs as wells may have to be purged with up to four well volumes before levels reach normal.

Are there different types of well water chlorination treatments?

Typically chlorination is done in stages. In fact, there are three types of chlorine used in the treatment of drinking water. Pure chlorine is rarely used. The three most common substances used are chlorine gas, sodium hypochlorite (household bleach), and calcium hypochlorite. The choice of which material is used depends on several factors including cost, available storage options, and pH conditions required. Chlorination affects pH and pH affects results. This fact is commonly overlooked in do-it-yourself residential treatment and is why it is recommended that chlorination treatment is performed by a professional. Chlorination raises the pH of water, so too much can reduce its effectiveness as a disinfectant. Chlorination is also used in water treatment strategies to oxidize iron and manganese. In this instance a higher pH is beneficial. These factors will help to determine which substance is used and why pre-treatment and post-treatment testing is crucial to effective treatment.

What about maintenance or follow up treatments after shocking a water well?

Post-treatment testing will determine if an additional course of treatment is necessary. Your well water professional can provide you with all of the information as to the actions necessary based on your test results.

How do I know if it is necessary to chlorinate my water well?

If your annual test results show elevated levels of bacteria, certain metals, or if your well is flooded during severe rain event you may need treatment. The best option is to work with a well water professional to review your annual test. If your area suffers a severe weather event such as major rain, or higher than normal snow pack that causes flooding you may want to have your well tested as a precaution.

Chlorination is an effective treatment for sanitizing your well. It is a process that is best handled by a well water professional. If you think your well may be at risk, contact your well water specialist and arrange to have your well tested. In the event, contamination is found, and chlorination is necessary, speak with your well water professional to determine all of your options. Chlorination works very well with other point-of-entry filtration systems. Your well water professional can give you all the options when it comes to water treatment.

Remember, If you receive your water from a private well, the task of keeping your water supply safe rests with you. Annual testing is the best way to make sure your water is contaminant free. Even if you do everything right, there are issues that may unexpectedly arise like bacterial growth due to flooding. Unexpected problems are the time to contact your Skillings and Sons well water professional for a solution.