or “UV” is a type of energy found
in the electromagnetic spectrum lying between
x-rays and visible light. Ultraviolet is divided
into four basic sections: UV-V, UV-A, UV-B and
UV-C. It is the UV-C, or germicidal UV, specifically
the 265nm wavelength of UV-C that offers
The ultraviolet energy attacks the genetic core
of the harmful microorganism and rearranges
the DNA/RNA preventing reproduction. If the
microbe can not replicate, it cannot infect! UV is
quick and the most cost effective way to disinfect
Is UV 100% effective?
UV disinfection typically offers a 99.99% reduction in both
bacteria and virus and is more effective than chemical disinfection
processes at destroying viruses.
Does UV remove E. coli?
Yes, E. coli requires a UV dose of between 6 to 12 mJ/cm2
to achieve 4-log disinfection. This is well within the capabilities
of the Sterilight UV system.
How much does it cost to operate?
UV systems are extremely economical to operate.
household UV system operates on the same power requirements
as a 40 watt light bulb!
Will UV change the taste or smell of my water?
UV is a physical disinfection process, no additives are
required. It does not change the taste or odour of the water.
It simply provides safe reliable disinfection.
How do I know the system is working?
All UV systems come with “lamp-out” monitors
which give an
audible and visual signal in case of lamp failure. Sterilight
GOLD systems incorporate true UV intensity monitors so an
alarm will sound if the disinfection effectiveness falls
a safe level.
Why do I need Disinfection?
Disinfection is required on all water supplies that are
by a municipal water source. Due to the uncertainties
that exist within some water systems, we can no longer rely
the fact that our water supplies “may be safe.” By
your own disinfection, you are taking the responsibility
ensuring the safety of the water supply for you and your
Do I need to Disinfect My Municipal
Our municipalities work very hard to provide safe disinfected
water supplies to their customers. However, you may wish
yourself that added “peace of mind” and install
a UV sterilizer to
protect against the possibility of drinking contaminated
What are the annual maintenance requirements?
UV systems contain no mechanical parts that wear out or
require maintenance. UV lamps have a useful life of approximately
8,000 hours and require replacement annually. Proper
maintenance of any pretreatment system is also required.
Should I be concerned about the adequacy of my
The UV system requires consistent power, both voltage and
frequency. To compensate for the fluctuations in power supplies,
Sterilight systems incorporate proprietary ICE ballast technology
to provide constant output voltage regardless of the fluctuations.
This results in consistent UV output and UV dose.
What size of system do I need?
An average household UV range in size from 5 to 12 gpm.
Determining your pumps flow rate will typically determine
required flow rate. (Sterilight offers many different models
sizes ranging from 1/2 gpm to 1,000 gpm.)
Should I shut my system off when I am not
The UV system should be left on at all times. By leaving
unit on, you will eliminate the potential problem of having
contamination pass through the system while the unit is off.
I need to worry about the quality of my water prior to the
For UV to be effective, it is recommended that the influent
water contain less than the following:
- iron less than 0.3
- hydrogen sulphide less than 10 ppm
- suspended solids less
than 10 ppm
- manganese less than 0.05
- ppm hardness less
than 7 gpg.
All conditions are treatable. To obtain adequate water
quality for the UV, please consult your local water treatment
professional for further assistance. To validate the disinfection
process, it is important to have the water tested for
bacteriological contaminants on a regular basis.
Is UV effective against protozoa such as
Cryptosporidium and Giardia Lamblia
Yes, as a result of recent findings by academic researchers,
it has now been proven that UV appears to be the best
available technology to treat protozoan cysts. In addition,
dose levels required to inactivate
these cysts are actually
quite low; less than10
mJ/cm2 for 99.99%
reduction of both