Chilliwack's Drinking Water

Drinking Water Q&A – August  2014

Is Chilliwack's water chlorinated?

The City of Chilliwack is a water supplier as defined under the Drinking Water Protection Act. All water suppliers are issued an annual permit to operate by the local health authority. Water suppliers are required to remain in compliance with conditions of their operating permit at all times. The City’s permit requires disinfection (chlorination) with a minimum target disinfection residual at the tap of 0.2 mg/L.

Secondary Disinfection does the following:

    • Inactivates microorganisms in the distribution system
    • Indicates distribution system intrusions, and
    • Controls biofilm growth

How does the City check for chlorine residual levels?

Operations staff use electronic chlorine test equipment to check chlorine residuals in all areas of the water distribution system. The target level for chlorine residual at the tap is 0.2mg/L , minimum. This is a low residual level which is enough to provide residual protection throughout the water system yet is low enough to keep taste and odour issues to a minimum.

How is Chilliwack water tested to ensure it remains safe to drink?

The Drinking Water Protection Act Regulations require all public water systems to take water samples every week. The City takes 44 water quality samples every week and these are sent to the BC Centre for Disease Control laboratory for testing.

What about disinfection by products?

Chlorine is one of the most widely used forms of disinfection in Canada and the United States. It is effective at killing many forms of waterborne bacteria and viruses. When chlorine is used to disinfect water supplies containing high levels of organic matter, water quality specialists have discovered that disinfection by-products (DPB’s) called trihalomethanes (THMs) and haloacetic acids (HAAs) can form.

DPB’s are a problem in water systems that use water with a high organic content, especially in systems that use surface water supplies. Chilliwack’s source water comes from the Sardis / Vedder aquifer and is of an extremely high quality with negligible organic content. What this means is that the risk of DBP formation would be almost non existent. With this being the case DBP’s do not manifest in the City’s water system. As a precautionary measure and in order to monitor for any DBP’s the City carries out testing procedures on an annual basis to check for DBP formation.

If you have any health concerns or health related questions about chlorinated water you can contact Fraser Health Authority directly at;
Phone : 604-870-7919
or by mail to
Fraser Health Authority
102 – 34194 Marshall Road
Abbotsford, BC
V2S 5E4

Why can’t the City use a non chemical system like ozone or UV?

There are a few non chemical water treatment options such as ozone, UV and micro filtration that are used by some water suppliers to purify their water. These methods are used for "primary" treatment of source water to remove impurities and to kill harmful bacteria so that the water can be used in the drinking water system. However, prior to entering the drinking water system, the water which has already undergone primary treatment, must go through a second process called "secondary disinfection" where a disinfection chemical, such as chlorine, is added to the water. The reason that both primary and secondary treatments are required is that UV, Ozone and filtration leave no disinfectant residual in the water as it flows through the water system - the addition of a secondary disinfectant allows for a disinfectant residual to remain in the water from source to tap.

In Chilliwack’s case the source water pumped from the aquifer is already very pure and free of contaminants and hence primary treatment is not required. Ozone and UV are not suitable for use as a secondary disinfectant because they leave no disinfectant residual in the system. Without exception, all secondary disinfection options involve the use of chemicals in one form or another to provide a stable disinfectant residual throughout the water system.

The City’s permit to operate requires a disinfectant residual to be maintained in the distribution system and chlorination achieves this.

Can I install a water filter in my home if I don’t want to drink chlorinated water?

There are household filter systems available that will remove chlorine from drinking water. Chlorinated water is supplied in compliance with Canadian Drinking Water Quality Guidelines and to not drink chlorinated water is a personal choice. In home water filter systems are readily available at any hardware store.


Chlorinated Water – Helpful Tips

How can I reduce the taste and odour of chlorine in my tap water ?

There are a number of things that you can do to reduce and even remove the taste and odour of chlorine from your tap water.

Water jugThe simplest thing you can do is to fill a jug with water and keep it in the fridge for drinking. Much of the chlorine taste and odour will leave the water if left overnight. Cold water also tastes and smells better than water at room temperature.

BritaUsing a water jug with a filter, such as a Brita filter jug, will reduce the taste and odour of chlorine in your water and the jug can be kept full in your fridge. Water can be consumed as soon as it has filtered into the jug.

Water filtersThere are various faucet mounted water filters available at most home improvement and department stores. These filters simply attach onto your existing faucet and up to 99% of chlorine is filtered from the water as it comes out of the tap.

Inline Water FilterFor a more permanent solution there are inline water filters available that can be plumbed directly into the cold water supply line under any sink. These filters remove chlorine as water flows through on its way to the faucet. Once installed the filters need to be changed every 10 to 12 months. There are a number of filters on the market varying in price from around $50 to $200. It should take a plumber about 2 hours to install an under sink filter.

Full House Water FilterTo remove chlorine from all fixtures in a house it is possible to buy a full house water filter system. These are larger size filters that are plumbed into the main cold water supply pipe where the pipe enters the house. These filters will remove chlorine so that all water used in the house is up to 99% chlorine free. This system can cost anywhere from $200 to $300 to buy and a full house filter can be installed by a plumber in about 1.5 hours.

With all of the above filter systems, in order for them to remain effective at chlorine removal, is it important that filters are changed at intervals given in the manufacturers instructions.

Can I use chlorinated water in my fish tank ?

Fish TankUsing chlorinated tap water in a fish tank / aquarium can cause damage to your biological filter. This damage will allow ammonia to start to build up in the tank, eventually becoming harmful to your fish. For this reason it is important that you treat your water to remove chlorine with an appropriate dechlorinator before you add it to your tank.

You should be able to get a dechlorinator from your local pet shop. Most stores carry a variety of dechlorinators. Remember, though, you only need to treat the new water you are adding to the tank, you do not need to treat the entire tank volume unless you are filling the tank for the first time, or have drained all the water from the tank for some reason. Dechlorinators are also generally very fast acting. Most will neutralize the chlorine in a bucketof water in just a minute or two.

Persons with weakend Immune systems

A healthy and safe drinking water source is especially important to those with weakened immune systems. The following links provide information on how to help prevent water-borne infections and how to disinfect drinking water.