Ultraviolet treatment is one of the chemical-free methods for disinfecting water from the mains or from well sources. It is particularly popular among the owners of private wells who may be concerned about the presence of bacteria.
UV light can be a good remover of microbes but cannot remove every type of contaminant.
How UV Disinfection Neutralizes Bacteria/Viruses Without Chemicals
Light exists on a spectrum of colors. Once the frequency of the waves goes past what is visible, it becomes ultraviolet, a type of radiation you may have heard of in relation to sunlight or even tanning beds.
Ultraviolet light can disrupt microorganisms’ ability to reproduce, which means they are neutralized after treatment without the need for chlorine or other chemical disinfectants. One thing it cannot do, however, is filter out physical contamination such as sediment or debris. Learn more on our page about bacteria disinfection.
Warning Signs You May Need UV
These situations should prompt you to have your water thoroughly tested:
- A positive result on regular testing for coliform bacteria.
- Flooding near a well.
- Heavy rainfall or runoff into your well.
- Sudden changes to the quality of well water.
- New knowledge of local contamination or water quality vulnerabilities.
Coliform testing is vital for water safety in your home because while most coliform bacteria will not make you sick, they act as a reliable warning sign that more dangerous contaminants could be present in the water supply. A positive result should always be investigated, not just masked with coliform-exclusive treatment.
Learn more from our coliform bacteria resource.
UV vs Chlorination for Private Wells
UV treatment is not universally better than chlorination. They both serve different purposes and are appropriate for different situations.
| Ultraviolet Treatment | Chlorination | |
|---|---|---|
| Summary | Antimicrobial disinfection using light. Can destroy chlorine-resistant bacteria such as Cryptosporidium, but leaves no trace, so bacteria can potentially regrow later. | Introduces a disinfecting chemical to the water, which remains after treatment to continue protecting water. |
| Taste/Odor | None – nothing is added to the water, so no change here. | Can leave a strong chemical taste and odor that requires additional filtering to remove. |
| Chemical Handling | None; no chemicals involved. | Sodium hypochlorite (liquid bleach) for running the system. Chemical byproducts over time can include trihalomethanes (THMs). |
| System Requirements | Reliable ongoing power supply and a yearly UV bulb change. | Constant monitoring of chemical levels and regular refilling. |
Maintenance Requirements
Your UV treatment system has several areas of maintenance to ensure continued good working order.
UV Lamp
The ultraviolet bulb should be replaced every twelve months, after approximately 9000 hours of use. The lamp may still glow at the end of the year, but the UV intensity will reduce over time, leading to less effective bacterial eradication.
Quartz Sleeve
This is the high-spec quartz glass screen covering the ultraviolet lamp inside the system. It keeps the bulb dry and safe from debris and must be cleaned when the bulb is changed. It may need to be cleaned more frequently in very hard water areas where scale can build up rapidly. Mineral scale can block the UV radiation, reducing bulb effectiveness.
Quartz sleeves need to be replaced every two to five years, or sooner if they become scratched or cracked. With a water softener, they aren’t replaced very often.
Filters
Sediment filters must be replaced every six to twelve months. You don’t want unwanted particles in your drinking water, and larger ones can block UV light from reaching microbes in the treatment tank.
Pairing UV With Sediment Pre-Filtration
It’s important that water is crystal clear in order for UV systems to successfully remove microorganisms and bacteria. Sediment and debris particles can interfere with the light able to reach microbes: light travels in straight lines, so anything can become a blocking obstacle.
Sediment pre-filters can protect your UV system from damage and improve the conditions for ultraviolet light treatment. Depending on the composition of your water, additional filters may be needed. Check out our information on well-water filtration for more detailed information.
Contact Aqua Clear Water Systems today for support with water testing and selecting a professional water filtration and treatment system for your home.
