Understanding Your UV System

Posted by Jeff Wahl on 12/23/2014
Understanding Your UV System
“When it comes to water, safety is of paramount concern and too often home owners trust the water implicitly when a residential UV System is installed.”

Over the last 25 years the use of Ultra Violet Disinfection Systems has become common place for keeping bacteria out of rural water supplies. If you own a home in the country, it is very likely that a UV System (also known as Blue Light or Sterilizer) is installed either at the kitchen sink or where the water enters the house.

Inactivation of harmful bacteria, viruses and dangerous parasitic protozoa such as Cryptosporidium and Giardia occurs at the point of contact between UV Rays and water inside of a stainless steel chamber. An Ultra Violet Lamp is the source of the UV Ray and radiates 360 degrees through a Quartz Sleeve which protects the lamp from coming in contact with water.

The benefit of this type of disinfection process is the instant neutralization of microorganisms preventing them from causing any harm. The process adds no by-products to the water. Today’s market for UV Systems is diverse and can often be challenging for an average homeowner to understand the water quality, maintenance and operational requirements to keep the water safe. These requirements are critical to water safety and include the following:

  • The Manufacturer’s Water Quality Requirements
  • Proper Pre-Treatment Achieving 5 Microns
  • Annual Ultra Violet Lamp Replacements
  • Frequent Cleaning of the Quartz Sleeve
  • Proper Plumbing Disinfection
  • Where the UV is to be Located
  • Understanding UV Transmittance
  • What to do During a Hydro Outage?
The complexity of each of these items can be addressed individually with respect to the impact on water safety. Paramount is the understanding that no residual disinfectant leaves the chamber nor does it enter any of the upstream plumbing or fixtures such as a sink, shower or toilet. If bacterial contamination is present in all of your plumbing, just installing a UV System will not remove it. Further steps must be taken to ensure the water safety. Water Quality can have an impact on the UV’s ability to “see” through the Quartz Sleeve. For simplicity this can be illustrated using a common light bulb analogy. If you paint a light bulb orange and turn it on, there is power and the light is on but it will not shine very brightly. The same analogy applies for a Quartz Sleeve, if Iron (orange staining) exists in the water there can be a “coating” of the Quartz Sleeve and diminish the strength of the UV Ray.

The same applies for Water Hardness and Sulphur. Turbid water (sediment) will also interfere with the UV Ray as microorganisms can “hide” in the particles and not be inactivated inside the chamber. If the water is not clear and has a colour, it is possible that a low UV Transmittance (Water Clarity) exists and the UV Ray will not shine properly.

Proper testing of water is a requirement for any UV Installation.
Rural areas experience power outages on a more frequent basis. Quite often people will turn on taps or flush toilets during an outage and inadvertently cross contaminate their plumbing without ever knowing it. Bacteria passes through the UV when it is not on and when power is restored the homeowner assumes that everything is okay because the UV is operational again. This may not be the case as bacteria have the opportunity to replicate on the other side of the operating UV Light.



Proper Education and / or an Automatic Solenoid Shut Off Valve Should be a Requirement.
Many systems are equipped with an automatic lamp replacement counter or reminder to ensure that the lamp is replaced at the required 1 Year Interval. There are systems which do not have this feature and rely on the customer to know that the lamp must be changed. The power indicator on most units is not a lamp replacement indicator and many homeowners are unaware of this. They do not change their lamp for years or until it burns out which has the potential to result in poor water quality while the homeowner is completely unaware.

Replace all UV Lamps after 12 Months of Running Time.
The Quartz Sleeve is often an unknown component of the UV System as many lamps can be changed without ever removing the sleeve. Proper cleaning of the sleeve is required and replacement sleeves should be at the 3 year interval. Sleeve cleaning and replacement is important for the UV Ray to be able to properly disinfect the water. It is also important to ensure that the O-Rings do not dry out and possibly cause a flood in your home. Do not touch the sleeve with bare hands as oils from the skin can also interfere with the disinfection process.

Properly Clean the Quartz Sleeve & Replace O-Rings. Change the Quartz Sleeve Every 3 Years.
Ultra Violet Lights are effective bacterial disinfection systems but they do not physically remove anything from water and do not remove chemicals or other contaminants that may be present in your water. For simplicity, if a pesticide is in the water and you send it through a UV the result would potentially be bacteria free water that contains the pesticide. Water can contain many contaminants that are not bacterial in nature and drinking water should be free of all contaminants and bacteria.

If you own a UV Light consider all of the necessary requirements to keep the water safe and if you are unsure contact a Certified Water Treatment Professional who can assist you to ensure that your water is safe.

Volume 1 – Issue 3 Wahl H2O - Water Awareness
Copyright 2014 Jeff Wahl – Wahl Water | All Rights Reserved
Contact Jeff via email jeff@wahlwater.com

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