Water Quality
Frequently Asked Questions

How much chlorine is in the water?

The water is chlorinated at the lake intake sites between 1.50 and 2.00 mg/L, depending on seasonal changes in water quality. Throughout the distribution system the chlorine concentration ranges between 0.10 mg/L and 0.90 mg/L. Concentrations greater than 0.10 mg/L must be maintained to ensure disinfection of the water as it is pumped through the watermains.

The taste and odour threshold for chlorine is 0.60 mg/L; sensitive individuals can smell or taste (usually smell) chlorine around 0.40 mg/L. Chlorine is very volatile and readily dissipates into the air; this is why people can smell it in the shower. Chlorine is easily removed by boiling the water, leaving it overnight in an open container (in the fridge) or by using a charcoal filter.

What is the level of Trihalomethanes from chlorination?

The concentration of Total THM’s in Kelowna’s drinking water ranges between 30 ppb and 60 ppb. The Health Guideline is 100 ppb and we’re far below this conservative level.

How much fluoride is in the water?

The City of Kelowna Water Utility stopped fluoridating in 1996; the natural occurring fluoride in Okanagan Lake is between 0.20 mg/L and 0.30 mg/L.

How hard is the water provided by the City of Kelowna Water Utility?

The water contains 100-120 mg/L or 5-7 gpg (grains per gallon) of total hardness. Both calcium and magnesium are measured for total hardness. Water is considered soft at 60 mg/L, hard at 200 mg/L and unacceptable at 500 mg/L.

What kind of filter should I use to remove Cryptosporidium and Giardia?

The water utility routinely monitors for cryptosporidium and giardia. Anyone with a home filter system should ensure the filter they are using is rated “1 micron absolute”. The “absolute” rating is very important because it means that pore size is not any bigger than 1 micron. Some filters are rated using a nominal pore size; this is not good enough to provide a proper barrier for Cryptosporidium and Giardia because they range in size from 1 to 5 microns.

Are herbicides and pesticides found in Okanagan Lake?

We have been monitoring for herbicides and pesticides since the beginning of the Water Quality Program in 1991. No trace of herbicides and/or pesticides has ever been found at any of the testing locations by the private labs hired to conduct the analyses. Testing is done for over 100 specific types of herbicides and pesticides.

Samples are collected during July as Agriculture Canada suggests July is the month mostly likely to produce a positive test indicating the presence of herbicides and/or pesticides. Since none has ever been found the Public Health Department has approved a monitoring change allowing scans to be done every second year rather than every year.

Are heavy metals present in Okanagan Lake?

The presence of heavy metals has never been detected. Dissolved and heavy metals are included on the annual Health Canada Potability scans and remain on a yearly analysis schedule. At one point in the program samples were collected each month from all pumpstations for heavy and dissolved metals scans.

Understanding Measurements

One part per million (ppm) or mg/L is similar to:

• 1 inch in 16 miles
• 1 minute in 2 years
• 1 cent in $10,000

One part per billion (ppb) is similar to:

• 1 inch in 16,000 miles
• 1 second in 32 years
• 1 cent in $10,000,000