Using UV Light to Treat Water: What You Need to Know

UV light has become an increasingly popular method for treating water, offering a chemical-free way to eliminate harmful microorganisms. This technology uses ultraviolet light to disrupt the DNA of bacteria, viruses, and other pathogens, rendering them harmless and preventing them from reproducing. As concerns about waterborne diseases grow, understanding how UV light can protect your water supply is essential for anyone looking to ensure the safety and quality of their drinking water.

How Does UV Water Treatment Work

A UV water purification system differs from other water treatment systems because it only uses ultraviolet light. UV systems are designed to destroy contaminants at the microbial level without filters or chemicals. Instead, they use a low-pressure monochromatic lamp to produce ultraviolet light that treats the water as it passes through the system. UV disinfection systems destroy about 99% of bacteria and other microorganisms. The treatment process is physical, instead of chemical, and provides instantaneous disinfection without altering the water’s taste. 

 

Learn more about Kind Water’s UV Water Purification System. 

 

Ultraviolet Light

The spectrum of light visible to the human eye includes wavelengths from 700 to 400 nanometers (nm). At the top of the range where wavelengths are the shortest, light takes on a violet color. Ultraviolet light derives its name from the fact that its wavelength is even shorter than violet light and is therefore invisible to the human eye. It also has more energy than visible light. 

The Effect of Ultraviolet Light on Bacteria

Ultraviolet light is broken down into different wavelengths: UVA, UVB, and UVC. UVA has the longest wavelengths, ranging from 400 to 315 nm. UVB wavelengths are in the middle at 315 to 280 nm and UVC has the shortest wavelengths at 280 to 100 nm. UVC has more energy than UVA and UVB and is germicidal. When microorganisms are exposed to UVC, the light penetrates their cell walls and destroys their DNA and RNA, effectively killing them. Because UVC does not reach the earth from the sun, bacteria have no previous exposure to UVC and therefore build up no immunity. With their DNA and RNA altered, bacteria are no longer able to replicate, which takes away their ability to cause human health issues.

Why and When Do I Need a UV Disinfection System?

In recent years, it has come to light that much of the country’s aging water infrastructure is deteriorating while demand is growing. Many public water system pipes are more than a century old, meaning they’re subject to breaks and leaks. Dig-ins, droughts, flooding, and other environmental conditions can also lead to underground pipe failure. When that happens, bacteria can enter the water system as it’s delivered to your home. Water treatment plants may also be shut down because of equipment failure or deliberate sabotage. Some microorganisms are resistant to chlorine, which is used to disinfect city water. So, it’s possible even treated water from municipalities could still be compromised. 

Homeowners relying on wells for their water should strongly consider investing in a UV treatment system. Coliform bacteria, which is found in human and animal waste as well as plants and soil, could contaminate private wells. This often occurs if the well cap is missing or defective, contaminants seep through or along the outside of the well casing, or if the well floods. While most coliform bacteria don’t cause serious illness, E. coli strains can be dangerous. Home UV treatment systems can protect your water from bacteria and other microorganisms, whether your well has been compromised or not. 

Boil Water Notices

When a line break or other system failure raises doubt about a public water system’s safety, authorities must issue a boil water notice. The boil water notice will state your water is not safe to drink unless it is boiled due to the possible presence of disease-causing organisms. Boiling water at high temperatures destroys any bacteria in the water. These notices can be issued for anywhere from 24 hours to several days.

Unfortunately, boil water notices are becoming more frequent. Texas, which has a fragile water system and sees severe weather conditions annually, is one example: in 2022, more than 3,000 notices were issued across the state. Texas isn’t the only state issuing an increasing number of boil water notices, though. It is a trend visible nationwide. To add to the problem, public water systems are sometimes slow to issue boil water notices. 

Microorganisms Killed By Ultraviolet Water Treatment

UV disinfection systems are highly efficient at removing microorganisms, including bacteria. Some of the microorganisms a UV disinfection system addresses include: 

• Bacteria
• Campylobacter
• E. coli
• Enteric viruses, including rotaviruses
• Enterococci
• Hepatitis A viruses
• Norovirus
• Protozoa, such as cryptosporidium and giardia
• Salmonella
• Shigella

How Safe Is UV Disinfection?

UV disinfection systems are incredibly safe. They have no moving parts and do not require the handling or disposal of harmful chemicals. They require almost no maintenance other than changing the ultraviolet bulb once a year and the UV sleeve every two years.

UV Water Treatment Benefits

UV water purification systems use no harsh chemicals and have no known threats to human health, making them a safe option for the environment and people alike. They also provide continuous protection, disinfecting water on a 24/7/365 basis without impacting water taste or odor. With only a small energy footprint, they use the same amount of energy as a regular light bulb, meaning homeowners won’t have to worry about a sizeable uptick in energy consumption due to their UV system. 

Disadvantages of UV Water Treatment

UV water treatment systems are only designed to kill bacteria and other microorganism. They will not remove other contaminants like heavy metals, organic material, or chemicals. System effectiveness may also be impacted if there is too much organic material present in water, as this reduces the amount of ultraviolet light reaching the water. For a complete water treatment solution that addresses a full range of needs, Kind Water recommends a system that includes UV purification as well as other filtration technologies.

 

Kind Water’s Whole House Salt-Free Water Softener and Filter Combo with UV