Chlorine in Drinking Water

Chlorine is an oxidizing, bleaching and disinfecting agent and has been used to disinfect water since the 1890s.

How Chlorine Disinfects Water

First of all, what is chlorine?

Chlorine is an element. And in its pure chemical form is a green gas. So chlorine is added to water for disinfecting through multiple forms, such as a gas, liquid or dry calcium.

So, why does chlorine disinfect water?

Water contains many different bacteria, parasites, viruses and contaminants. Chlorine attacks many of those contaminants. Chlorine's chemical elements attack cell walls, slime coatings and shells. Therefore destroying the contaminants. And preventing the spreading of germs through additional reproduction.

And how is it added to water?

As a natural element, chlorine is a gas. However, the structure of the element is applied to water in a few different ways. Chlorine is added to water through a dry calcium hypochlorite, a liquid sodium hypochlorite solution like bleach, or as a chlorine gas. So no matter which way the chlorine is added, it works to destroy harmful contaminants in water.

How much chlorine is in municipal water supplies?

The United States Environmental Protection Agency (EPA) maintains the National Primary Drinking Water Regulations (NPDWR). So the U.S. government sets the standards for how much chlorine is acceptable in municipal water supplies. And the EPA does still use chlorine in water to prevent the spread of harmful diseases and waterborne illnesses. Similarly to the 1890s. While the EPA sets the limit of 4 parts per million for chlorine in drinking water, there are still potential side effects of overexposure to the element.

What are the side effects of chlorine?

Because chlorine destroys harmful organisms quickly, it has been an effective way of treating water for more than 100 years. As a result, you'll be able to smell it and taste chlorine in your water.
High levels of chlorine leave an unpleasant, bleach-like taste in your food. And outside of food, chlorine dries out skin and hair. Furthermore, it can causes rashes, especially if your home contains hard water.

Culligan Solutions

Reverse Osmosis

An RO system reduces contaminants, like chlorine in drinking water. Using an activated carbon filter and a semipermeable membrane.

What is RO Filtration?

Reverse Osmosis is a water treatment method filtering water in about four steps: pre-filtration, reverse osmosis, drainage and storage.
So let's expand on these four steps.
First, pressurized water moves through a particle filter. And removes impurities like sand, salt and sediment.
After the particle filter, water passes through an activated carbon filter. Because the activated carbon filter traps and removes minerals and contaminants. As well as chlorine, mercury, copper and other pesticides. Concluding the first two steps of the process known as the pre-filtration stage.
Next, pressurized water forces its way through a semipermeable membrane. And trapping the smallest impurities so only water passes through.
Finally, removed contaminants flush away in the last stage, the discharge stage. So a storage tank collects treated water, and contaminants are flushed away.
Before the water is sent to the faucet, it undergoes one final activated-carbon filtration. Improving the taste and quality of the water for household use.

What does RO Filtration Remove*?


While chlorine is used to disinfect water, reverse osmosis filtration removes chlorine and the contaminants chlorine destroys. So the RO filtration method water is filtered, reducing 99 percent of contaminants. And does not taste or smell like chlorine.


A lesser-known contaminant is chloramine. Chloramine contributes to an altered taste or smell in drinking water.


Exposure to lead is never safe, in any amount. And it is especially dangerous for children. Lead is difficult to detect. Because it cannot be seen, smelled or tasted.


Mercury comes from the natural degassing of the earth's crust. And from human activities like burning fossil fuels. Overexposure to mercury damages the brain, kidneys or even a developing fetus.


Hexavalent chromium is another name for chromium-6. And it is a known carcinogen. So it links to cancer, reproductive issues, asthma attacks and other severe effects. Chromium-6 is an industrial chemical found in all 50 states.


High sediment levels in water cause cloudiness or haziness. So the higher the level of cloudiness or haziness, the higher probability of sediment. And sediment causes gastrointestinal issues.

UV Filtration

UV Filtration is a safe and natural way to treat water. And it's also low-maintenance.

What is UV Filtration?

First, let's start with UV. What is UV? UV is short for ultraviolet. And ultraviolet is a term describing a wavelength of energy on the electromagnetic (EM) spectrum.The EM spectrum is a tool scientists use to show how energy moves in and out of light.
UV light is powerful enough to kill bacteria. Because the wavelengths of UV light produce enough energy, it disinfects water. And makes water safer for us to drink.

How does UV Filtration Disinfect Water?

Four parts assemble to produce the UV Filtration system. First, a lamp generates UV light. Second, a controller powers the lamp. Third, a UV chamber exposes the water to the UV light. And fourth, a quartz sleeve protects the UV light.


At the heart of every UV system is the lamp. Because energy comes from light, without the lamp there would be no energy to kill bacteria.


Power to the UV system comes from the controller. So the controller generates energy. And the UV light makes the water safer.

UV Chamber:

Contaminated water enters a UV chamber. And the UV chamber exposes water to light. Consequently, killing bacteria and making the water safer to consume.

Quartz Sleeve:

The quartz sleeve protects the lamp from the activity inside the UV chamber. In addition to protecting the lamp, the sleeve makes sure the correct amount of energy is appropriate and consistent. Resulting in a constant flow of energy for the water.
Quartz sleeves are made of 100 percent fused silica quartz. And they have a high UV transmittance. So more light passes through the water.

What contaminants does UV Filtration Treat?


Cryptosporidiosis is also known as cryptosporidium. A disease microscopic parasites carry. As a result symptoms such as diarrhea, dehydration, nausea, vomiting and fever occur.
Crypto is found in areas throughout the United States and the world. Therefore, it is one of the leading causes of waterborne illness in humans in North America.
As a result, this parasite has an even greater impact on people with weak immune systems. Including those who are receiving treatment for AIDS, cancer and organ transplant. And anyone using immunosuppressive drugs.


Salmonella is a well-known type of bacteria. And a cause of illness for over the past 100 years.
Several different variations of Salmonella spread through human and animal feces.
Every year in the United States, salmonella causes an estimated:
  • 1.2 million illnesses
  • 23,000 hospitalizations
  • 450 deaths


Another parasite causing negative health effects such as diarrhea is giardia. Because Giardia is a parasite with an outer shell, it is harder to kill with chemicals like bleach or chlorine. So while chemicals have a difficult time breaking down the DNA of the parasite, UV light does not.


Some types of E. coli cause diarrhea. While others cause urinary tract infections (UTIs), respiratory illnesses and other contagious diseases.

Benefits of UV Disinfection

Some benefits of our UV Disinfection include:
  • Low maintenance.
  • Reduce the carbon footprint.
  • Avoid harsh chemicals like bleach and chlorine.
  • Unchanging taste, smell and appearance of water.
  • Low operating costs (pennies per day).
  • Works well with other Culligan water treatments.

Conclusion: Chlorine in Drinking Water

Although chlorine still treats municipal water supplies, at Culligan, we give you multiple water treatment options. So whether you want to learn about Reverse Osmosis Filtration or UV Disinfection for your home, a local Culligan expert is just a call away.