Wednesday, August 24, 2016

Engineers create water quality measuring tool

by Staff Writer - Vernon Morning Star posted Aug 24, 2016 at 1:00 AM
University of B.C. engineers have created a tool that will help communities measure water quality, as a way to ensure clean and safe drinking water is coming out of the taps. Nilufar Islam, who recently received her PhD from UBC Okanagan, has spent the better part of her career creating methods to improve drinking water quality. Working with Rehan Sadiq, associate dean of the School of Engineering, and Manuel Rodriguez, from Laval University, she developed a water quality index to improve the interpretation of drinking water quality in distribution networks. Disinfectants, commonly used in water to ensure it is safe to drink, can react with natural organic matters in the water, or the distribution system, to create disinfection byproducts (DBPs). These DBPs including trihalomethanes and haloacetic acids are known to have potential reproductive and development effects. It’s like a catch-22,” said Islam.

“Disinfection is necessary to ensure microbiological water quality, but it can produce DBPs when used excessively. DBPs in municipal water may potentially lead to detrimental health impacts. The question became, how can we make sure that our drinking water contains DBPs within acceptable limit without degrading microbiological water quality?” Noting it’s almost impossible for the general consumer to interpret complex regulatory violations, Islam and Sadiq created a tool, known as the non-compliance potential (NCP) index, to make interpreting measurements of diverse water quality parameters as easy as possible. The index has been used recently to study water distribution systems in many Canadian cities. The NCP index is designed to merge difficult to understand data into simple indicators that show municipalities whether their water systems are, or are likely to, contain unwanted byproducts that are created when disinfectants react with organic materials in water system. “As many small municipalities do not have the technical and financial resources to collect and decipher water quality data on a regular basis, tools such as the NCP index could help them target how and where they spend their time and money,” said Sadiq. In assessing the benefit of the NCP index, researchers measured water quality at various points in several water distribution systems. They then measured the systems to determine which areas had or were most likely to have compromised water quality. “With so many small municipalities required to operate and maintain water systems, we feel it is important to ensure they have the tools to understand how their systems are operating and where best to target their capital investments,” said Sadiq. “It wouldn’t be possible to examine the whole system at a time, so helping municipal engineers better prioritize operations is a good way to ensure our water quality is maintained.”
The maximum acceptable concentration (MAC) for trihalomethanesFootnote1 (THMs) in drinking water is 0.100 mg/L (100 µg/L) based on a locational running annual average of a minimum of quarterly samples taken at the point in the distribution system with the highest potential THM levels.


The maximum acceptable concentration (MAC) for bromodichloromethane (BDCM) in drinking water is 0.016 mg/L (16 µg/L) monitored at the point in the distribution system with the highest potential THM levels.

Other Considerations

Utilities should make every effort to maintain concentrations as low as reasonably achievable without compromising the effectiveness of disinfection.

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