A term that was plucked from obscurity for a stay on the front pages of Vancouver’s newspapers a few months ago is now making appearances in the Kelowna press: Turbidity.

Turbidity is defined as “muddiness created by stirring up sediment or having foreign particles suspended”. Why do we care about this? Anybody who lived in Kelowna in 1996 will recall that many people fell ill due to ingesting a parasite called Cryptosporidium. Little beasties like Cryptosporidium, and Giardia (more popularly known as beaver fever) can cling to the suspended particles in turbid water like a tick on an unprotected ankle. The parasites then use the particles as a shield to avoid being killed by the disinfectants that are added to drinking water, usually chlorine. Some water districts, such as the City of Kelowna’s water utility, Turbidity is much more of an issue if your drinking water is sourced from water found above ground like rivers, lakes and creeks. This is because (especially at this time of year with spring runoff turning normally placid streams into raging muddy torrents) clay, silt and various kinds of organic and inorganic matter get tossed around like margarita mix and tequila in a blender. A margarita should be well blended, your drinking water . . . not so much. So if your water comes from a well, underground spring or a large lake you will probably never have to worry about turbidity.

Why has turbidity become such a talked-about phenomena lately? Because the provincial government redefined the standards that govern when the general public is informed of turbidity levels making boil-water advisories much more common than they used to be. Any time the level rises above 1 NTU a boil-water advisory is now issued. What’s an NTU you ask? It’s a nephelometric turbidity unit. Simply put, it’s a measurement of how much light gets scattered and absorbed by water by bouncing off sediments instead of traveling in a straight line. More simply put, it tells you how muddy your water is. I’d like to make a joke referencing blues legend Muddy Waters at this point but we’re having a serious chat about drinking water so I won’t. I will give you a frame of reference – you can’t see any difference in water that has a turbidity rating of 1 or 2 NTU’s. AT 5 NTU’s you will notice cloudiness in the water and at 25 NTU’s you would think twice about filling your dog’s dish with it, let alone drinking it yourself. A government-defined turbidity rating of Good, which is less than 1 NTU means newborns or anybody with a compromised immune system should boil their water. A Fair rating (1-5 NTU’s) means that children, the elderly and those with compromised immune systems should boil their water. Poor (greater than 5 NTU’s) indicates that everyone should boil their water for at least a minute. How closely should we pay attention to water quality advisories? Hard to say. Two million people in the Vancouver area were under a boil water advisory and there were no reported incidences of drinking water-related illnesses. My tap water was recently under a water quality advisory. My immune system is fine and, while I may occasionally be accused of being immature, I am far from newborn. Nevertheless, I erred on the side of caution and only used my tap water for coffee, showers and brushing my teeth.

There are currently two water districts in the Kelowna area that have recently issued water quality advisories. You can check their web pages for updates on the turbidity of your drinking water. The South East Kelowna Irrigation District’s page is http://www.sekid.ca/ and the Black Mountain Irrigation District has a very detailed, regularly updated report at http://www.bmid.ca. If you’re not sure where your water comes from you can check the Kelowna Joint Water Committee web page at http://www.kjwc.org.