UV - A Time for Change

Residential ultra violet (UV) disinfection systems are one of the most misapplied and misunderstood pieces of water treatment equipment sold on the market today. Consumers can readily purchase systems from box store retailers, water treatment dealers, heating & air conditioning dealers, plumbing dealers and online from various companies without ever being informed of their operating requirements to ensure proper water disinfection. 

Almost 20 years of field experience has shown me that 8 out of every 10 UV systems are installed incorrectly, do not have the proper incoming water quality and have no monitoring or shutoff devices. This does not change the fact that they are relied upon implicitly to provide safe drinking water in rural communities across the country.

A recent experience with a consumer clearly illustrates this point. Having a drilled well on their property, they were concerned about bacteria and had a plumber install a sediment filter and UV system at their request. The water was never tested prior to the installation and two months later there was a high E-Coli count present in a water sample. 

After investigation it was determined thick calcification on the UV quartz sleeve which was a result of the 97 grains hardness level present in the water prevented the UV ray from properly contacting the water. The calcification had prevented the UV system from operating correctly and there was no monitoring device to detect the problem. 

The UV system never went into alarm and the consumer was never informed of the requirement for <7 grains of hardness when the plumber installed the equipment. This requirement was clearly stated in the owner’s manual for the system. Numerous other examples can be shown for iron, tannin, sulphur, turbidity and power outages. Incorrect system installations prior to pressure tanks, water softeners, iron filters or without a proper sediment filter are also very common.

 

In the province of Ontario, regulations 170/03 & 319/08 govern public facilities such as nursing homes, child care centers, campgrounds, marina’s and various other facilities which serve water to the public from non-municipal sources. These regulations use the NSF 55 Class A certification for UV systems which requires a 40mj UV dosage, a monitoring device (sensor) for the UV transmission level and an audible alarm for adverse conditions. It also requires an automatic safety shut off device (solenoid valve) to stop water flow when the UV system fails to meet any of its operating conditions. 

This Certification is not a Requirement for Residential Systems 

Why do regulations require these safety measures for public facilities and not regulate the private sale of UV systems? The risk of bacterial contamination is just as great for one family as it is for an entire campground full of people or daycare center full of toddlers. 

Manufacturer’s offer residential systems with both sensors and solenoid valves. Most plumbers and water treatment dealers see them as troublesome with “nuisance” alarms and frequent “no water” calls. When water is properly treated and the operating conditions met, UV systems with sensors and solenoid valves can provide the highest level of bacterial safety in residential applications.

 

The time has come for change in the industry to ensure the safety of consumer’s drinking water. Sales of ultra violet disinfection systems should be by licensed dealers / retailers who educate the consumer and properly apply the equipment to incoming water quality, flow and system requirements. Licensed electricians, plumbers, gas fitters, pump installers and mechanics all serve the public with measurable standards. Why does this “standard” not apply for water treatment equipment that rural Ontarian's rely on for safe drinking water every single day?