City Departments
Drinking Water Frequently Asked Questions
Yes, however, naturally occurring constituents in the water (such as iron) may form and settle out in the piping system. Well-run water utilities will have ongoing programs of flushing and cleaning for the distribution pipes to ensure that these pipes are kept clean. Flushing is done by opening fire hydrants and letting the water rush out. Without flushing, material such as iron could gather in the piping and come out through faucets of your home.
Another way to clean pipes is by forcing a tight-fitting plastic sponge through the pipe using water pressure. The sponge scrapes the pipe walls clean. The dirt is then flushed out through a fire hydrant. Similar devices with other designs are also available.
Keeping water pipes clean is a big job, as there are over 410 kilometres of pipe in the City of Cambridge.
2. I have seen work crews cleaning watermains and the water they flush out looks terrible. How can the water be safe if the pipes are so dirty?
Almost all water pipes have a thin film of rust and harmless microbes on the inside. Experience has shown that this thin film causes no health problems. Build-up of this material may, however, cause problems such as clogging of fixtures, causing the tap water to look bad, or using up the disinfectant in the water as it passes through the pipes. The City of Cambridge has a regular program of flushing and cleaning the distribution pipes. When all of this material is removed from the walls of long lengths of pipe and it comes out through a fire hydrant all at once, it looks worse than it really is. If you watch the workers do this, you will notice that the water cleans up rather quickly.
3. How does a water utility detect a major leak in the distribution piping system?
A major leak can be detected by:
- Visual detection (water on the ground) by employees who work on the water system.
- A loss in pressure that can be detected by the City of Cambridge water staff and customers.
- Reports by public-minded citizens.
- Annual leak detection surveys undertaken by City of Cambridge water staff.
Once a leak is suspected, its precise location is determined by water personnel. Sensitive listening devices are used to detect the sound of the leaking water underground.
Stopping leaks is important because leaks waste water, adding cost to both the water distributor and you. The distributor doesn't get paid for the water that is lost to leaks, but may pass its cost along to the customers. The industry average for the water lost from leaks is 12 to 15 percent, although most distributors try to keep such losses to around 10 percent.
Any leakage that occurs within the boundary of your property is your responsibility and must be repaired at your own expense. Prompt repair is to your benefit because as long as the pipe is leaking, your water bill will be higher and it may cause property damage.
4. Fixing a broken water pipe looks like a dirty job. How is the inside of the pipe cleaned afterward?
After work is done, the pipe is filled with water containing a large amount of chlorine. Holding this water in the pipe for a time kills all the germs.
This is not the end of the story, however. The next problem is how to dispose of all this water that contains so much chlorine. Regulations control its disposal. A chemical must be added to react with the chlorine and destroy it before the water can be flushed out of the pipe and discharged, or the highly chlorinated water must be discharged to an area where it will not have an adverse impact on the environment. Further testing for the presence of potentially harmful bacteria is also done to ensure there are no health hazards present prior to the water being made available to the public.
5. Why is some drinking water stored in large tanks high above the ground?
Two reasons. First, this type of storage ensures that water pressure and water volume are sufficient to fight fires. The second reason is to provide an extra source of drinking water during the day when water use is high. The tanks are refilled at night when drinking water use is low. Water suppliers must be very careful of these storage tanks because water may stay in them a long time. Thus, there is a potential for a decline in water quality. Regular inspection and sampling will prevent problems.
6. I have a water softener, but I still get spots on my bathroom tile. Why is this?
First, a little easy chemistry. All water contains dissolved non-toxic minerals. Calcium, magnesium, sodium, sulfate, chloride, bicarbonate are the most common. These have no health effects. If you put water in a dish and let it evaporate, the white stuff that is left are these minerals.
Two of these minerals, calcium and magnesium, cause "hardness". Because they interfere with suds and thus make washing "hard" (difficult), they are referred to as causing hardness. A water softener like you have trades (exchanges) the calcium and magnesium for sodium or potassium, so the water leaving the softener has no calcium and magnesium (thus no hardness) but more sodium or potassium.
Thus, minerals were not eliminated during softening, just traded. If you put the softened water in a dish and let it evaporate, the white stuff left over, although it would be different it would look the same and would equal the same amount as before the softener was installed.
If you had installed a reverse osmosis unit instead of a water softener, it would actually remove minerals from the water, not just exchange them, and you would not experience this problem.
7. How much water does one person use each day?
Total water use varies depending on lawn watering, if any, and whether a home has a washing machine and a dishwasher. The US average is nearly 50 gallons used each day by each person. Of this, the amount used for cooking and drinking varies among individuals, from about 13 ounces to about 2 quarts. The average use is about 2.5 pints - about half for plain water consumed as a beverage and the rest consumed in other beverages (juice, coffee, and so forth) and used for cooking.
Because of other uses in a community, the water supplier pumps much more water than is just used in households. A study of 1,100 water suppliers around the United States showed that to supply all the water needed for all uses the average amount pumped was 180 gallons each day for each person.
In Canada, average total home water use is about 60 US gallons for each person each day. The use for drinking water has been estimated at about 1.5 litres (1.5 quarts) each day.
8. Where does the water go when it goes down the drain?
In the City of Cambridge you are on a sanitary sewer system and all of the drains in your house are connected to a single pipe that leads to the street. The pipe in the street collects the wastewater from all the homes in your area and takes it to a larger pipe that collects wastewater from other homes. The wastewater then flows into still bigger pipes that connect various neighbourhoods. Think of a large tree with your house at the tip of a branch near the top. Like the tree branches that are bigger nearer the ground, the pipes in the wastewater collection system are larger and contain more liquid as they near the wastewater treatment plant. Here, the wastewater is treated and cleaned so that it can be put back into the environment without harming anything. A drinking water distribution system looks similar but in this case the drinking water goes from the treatment plant to your home.
9. What activity in my home uses the most water?
Toilet flushing is by far the largest single use of water in a home. Most toilets use from 4 to 6 gallons (15 to 23 litres) of water for each flush. Canadian flush toilets use about 4 to 6 imperial gallons (18 to 28 litres). On the average, a dishwasher uses about 50 percent less water than the amount used when you wash and rinse dishes by hand if the dishes are not pre-rinsed and if only full loads are washed in the dishwasher.
Without counting lawn watering, typical percentages of water use for a family of four are:
- Toilet flushing - 40%
- Bath and shower - 32%
- Laundry - 14%
- Dishwashing - 6%
- Cooking and drinking - 5%
- Bathroom sink - 3 %
In the United States, the National Energy Act of 1992 requires low-volume toilets in new construction or as replacement in existing homes after January 1, 1994. Businesses were to have complied by 1997. Ultra-low-flow (ULF) toilets are available that use only 1.4 to 1.6 gallons (6 litres) for each flush. Since 1996, the Ontario Building Code has required all new homes to have only low volume toilets installed. For toilets installed prior to this date, many cities and municipalities have implemented replacement programs by offering rebates for those who have replaced their older less efficient toilets with new low volume ones. The Region of Waterloo Water Efficiency Department operates this service for all Waterloo Region citizens and more information can be found on their website www.region.waterloo.on.ca
10. My water faucet drips. Should I bother to fix it?
Yes. Drips waste a precious product, and this waste should be stopped, even though the dripping water may not register on your water meter. To find out how much water you're wasting, put an 8-ounce (236 millilitre) measuring cup (or anything that will measure 8 ounces) under the drip and find out how many minutes it takes to fill it up. Divide the filling time into 90 (90 divided by minutes to fill) to get the gallons of water wasted each day.
As an example, if you have a faucet that dripped 60 times a minute (once each second) this adds up to over 3 gallons (12 litres) each day or 1,225 gallons (4,630 litres) each year, enough to fill more than twenty-two 55-gallon (210 litre) drums, just from one dripping faucet. This leak would fill the 8-ounce (236 millilitre) measuring cup in less than 30 minutes.