Ultra Violet Water Treatment FAQs
What is a UV Water Treatment System?
A UV Water Treatment systems uses a method known as Ultraviolet germicidal irradiation (UVGI). This method uses ultraviolet (UV) light at sufficiently short wavelength to kill microorganisms. It is predominantly used in situations where there is a private water supply treatment requirement.
UV effective against protozoa such as Cryptosporidium & Giardia lamblia?
Yes, it is proven that UV is the best available technology to treat these protozoan cysts. In addition,the dose levels required to inactivate these cysts are actually quite low: less than 10mJ/cm² for 99.9% reduction of Cryptosporidium parvum and Giardia lamblia.
Why disinfect a water supply?
Disinfection is recommended for all water supplies that are not protected by a municipal water source. Unfortunately, due to the uncertainties that exist with some current water supplies, it is not necessarily safe to rely on the fact that water supplies “may be safe”.
Does UV remove E. Coli?
Yes, E. Coli requires a dose of up to 10mJ/cm² to achieve a 4 log reduction. WATTS® UV Systems deliver 30mJ/cm² at end of lamp life.
Is UV 100% effective?
UV disinfection typically offers 4 log reduction (99.99%) for both bacteria & most viruses. UV is more effective than chemical disinfection processes at destroying a wide range of viruses. See also pre-filtration.
How do I know the system is working?
WATTS® UV Systems are equipped with ballasts that emit an audible and visual alarm indicating lamp failure.
Is it necessary to disinfect a municipal water supply?
Municipal water suppliers work hard to provide safe disinfected water – however, even in the most advanced & best “policed” areas of Europe and the USA there have been outbreaks of Cryptosporidium – it is worthwhile noting : only one cyst will cause vomiting & illness.
How much does it cost to operate UV Systems?
A WATTS® 45 lpm UV system will use 110 watts, similar to a 100 watt light bulb.
Will a UV change the taste of water?
No, UV is a physical process.
Maintenance?
A WATTS® UV lamp should be changed every 9,000 hours – so approximately once per year.
Is pre-filtration required?
Yes, microbes can be shielded by suspended particles (sediment/turbidity), it is recommended that a pre-filter be installed of at least 5 microns, this should be changed every 6 months to prevent"mitosis", commonly called "grow through".
Is the electrical supply adequate?
WATTS® UV systems are all supplied with a ballast that provides a constant output regardless of input frequency & voltage, which results in consistent UV output.
What size UV?
Average households range from 15 lpm to 46 lpm – covered by the WATTS® range.