The Water Division provides clean and safe drinking water to all the residents and businesses within the City of Cambridge. Our Drinking Water Quality Management System is in place to keep our water safe. Water samples from around the City continue to confirm our water quality exceeds provincial standards.

Lead Sampling Program

In 2007, the Ontario Ministry of the Environment and Climate Change (MOECC) implemented a Community Lead Sampling Program under which the City of Cambridge is required to collect, analyze and submit the results of water samples taken in areas suspected of having lead service pipes. Prior to the mid-1950’s, lead was commonly used to build pipes that deliver water from the water main on the street into residential homes. This section of pipe is called the water service pipe.

Twice every year, the City of Cambridge is required to collect water samples to determine if lead is detected in the drinking water above the regulated limit of 10 parts per billion (ppb).

The MOECC requires the following samples to be collected twice per year:

  • 50 residential buildings;
  • 5 non-residential (businesses); and
  • 10 distribution samples (from fire hydrants).

The results are analyzed by an accredited laboratory and provided to homeowners/occupants within 14 days of sample collection date.

I received a letter from the City requesting to collect a water sample. What does this mean?

If you received a letter from the City, we are canvassing your area for participants in the Lead Sampling Program. Your area was chosen because the age of your home may indicate that the water service pipe may be lead. Please note that even if the plumbing inside your house has been replaced, the underground water service pipe coming from the water main to your home could be lead or have lead-containing solder, which could impact your water quality.

Please contact 519-621-0740 or email to request an appointment or if you have any questions or concerns related to lead in your drinking water. 

Drinking Water Quality Management System

Approved by City Council on November 10, 2008 and developed by the Cambridge Public Works department, the Drinking Water Quality Management System (DWQMS) Operational Plan, helps ensure that the City of Cambridge can operate its own water systems and the drinking water quality is not just maintained but continually improved. Our DWQMS includes 21 elements that all QMSs must conform to, including the City of Cambridge Quality Policy.

Drinking Water Quality Management System Poster

Water Testing

In accordance with provincial legislation, the City of Cambridge regularly samples its water and analyzes it for water quality. This helps to ensure that the water supplied to the public meets the Ministry of the Environment's water quality standard. Our Annual Water Quality Reports summarize testing results for review by City Council and the Ministry of the Environment.

If the water quality does not meet the provincial standards, actions as specified through legislation must be followed until it can be proven that the water meets the standard. These actions include immediate notification to the Ministry of the Environment and the local Medical Officer of Health, as well as watermain flushing, increased disinfectant levels and resampling.

Annual water samples
Frequency of annual water sample testing
Reason for SamplingNumber of Samples
Per Year Legislative Requirement 
Number of Samples
Typically Taken Per Year
Bacteria (E.Coli/Total Coliform) Testing 1356 1600
Bacteria (HPC) Testing 339 650
Chlorine Residual Testing 364 832
Lead (internal plumbing) Testing 220 220
Lead (distribution system) Testing 20 20
THM & HAA (organics) Testing 8 8


Door-to-door water testing sales

Please note that the City of Cambridge does not conduct water-related sales of any kind and does not sell, market or endorse any products.

City staff who knock on your door to collect a water sample only do so after a letter notification of sampling has been delivered the week before. The City only collects samples from homes to meet requirements of the Lead Sampling Program.

Residents are advised to use caution when solicited for a water test by a third party and when sharing personal information with people you don’t know.

If you suspect fraud, please call Waterloo Regional Police Services (WRPS) at (519) 653-7700 or Consumer Protection Ontario at (416) 326-8800.

If you have a concern about drinking water quality in the City of Cambridge, please contact Water Services at 519-621-0740. For questions or concerns related to lead in drinking water, you can email

Water Main Cleaning Program

Water mains are underground pipes that carry water from pumping stations to your street, and service pipes connected to your house. The City of Cambridge cleans water mains on a regular basis in order to remove accumulated material and maintain drinking water quality.

The annual Water Main Cleaning Program consists of a combination of water main swabbing and flushing. No chemical cleaning products are used in this process, and minimal water service interruptions are experienced by customers.

Water main cleaning will commence the first week of April 2024 for approximately 6 weeks. The areas of the city to receive cleaning are outlined on this map. In advance of work being done, blue card notices will be hand delivered to customers who are in the immediate area of the cleaning activities. Customers outside of these areas may also experience discoloured water. This is a temporary condition, and should clear within a few hours of daily work concluding. If you have any questions, call Service Cambridge at 519-623-1340.

I received a door hanger notice. What should I do?

Before Flushing

Since water cannot be used during the cleaning process, you should:

  • Fill a clean container with tap water for drinking and cooking.
  • Complete dishwashing, clothes washing, and other activities prior to the cleaning start time indicated on the door hanger notice you receive.
  • Turn off the main water supply by using the shut off valve (usually located at your water meter).
  • If shutting the valve is impossible and you have an automatic water filtration system (ie. water softener), put the system on bypass to prevent it from using water.

During Flushing

  • Do not use any water or flush your toilet to avoid drawing discoloured water into your home’s pipes and causing internal plumbing issues.

After Flushing

  • Use a cold, hard (unsoftened) water tap closest to your water meter, like a basement laundry tub, to flush your water service.
  • Some customers may experience temporary discoulouration of their water, which should not be consumed.
  • If you notice discoloured water, run the cold, hard (unsoftened) water tap closest to your water meter for 10 minutes at medium speed, pencil size stream. 
  • If the water remains discoloured after 10 minutes of running your tap, turn off the tap, wait 60 minutes and repeat the 10-minute flushing process again.
  • If your water does not clear after 2 hours, please contact Service Cambridge at 519-623-1340 for assistance.

Frequently asked questions

How does the City notify customers affected by the program?

We use a number of methods to inform customers of planned water main cleaning and possible discoloured water caused by the program. Notification is done by the following methods:

  • Door hanger notifications are placed on customer’s door notifying of cleaning day and time
  • Advertisements in the Cambridge Times newspaper
  • Information shared through the City’s official social media accounts (Twitter and Facebook)

What is the cleaning process?

Water main flushing is done by forcing water through water mains at high speed and discharging it through a fire hydrant. The fast-moving water flow scours and cleans out mineral deposits and sediment that may have built up over time.

Water main swabbing entails inserting a soft material bullet-shaped device, called a swab, into the water main through a fire hydrant. The diameter is slightly larger than the water main and the swab is pushed through the water main by water pressure. As it passes through the water main, the swab scours the inside of the pipe and removed any built-up material. 

Will water main cleaning impact my water service?

Your water service will not be turned off but we advise that you do not use water during the cleaning process to avoid drawing discoloured water into your home’s pipes.

Is flushing my pipes to remove discoloured water expensive for me?

At the current 2022 water and wastewater rates ($4.9499 per m³) a customer in Cambridge pays approximately 8 cents for every minute that a tap runs. The recommended 10-minute flushing process will cost you approximately 34 cents.

Drinking Water System Inspection Report

2023-2024 Ministry of Environment, Water Inspection Report

2022-2023 Ministry of Environment, Water Inspection Report
2021-2022 Ministry of Environment, Water Inspection Report

2020-2021 Ministry of Environment, Water Inspection Report

2019-2020 Ministry of Environment, Water Inspection Report

Frequently asked questions
Are the pipes that carry drinking water from the treatment plant to my home clean?

Yes, however, naturally occurring elements in the water (such as iron) may form and settle in the piping system. Ongoing flushing and cleaning programs for distribution pipes get rid of these natural elements.

Flushing is done by opening fire hydrants and letting the water rush out. 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.

The water flushed out of watermains by work crews 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. Build-up of this material may cause problems such as clogging of fixtures, making the tap water look bad or using up the disinfectant in the water as it passes through the pipes.

The City of Cambridge has regular flushing and cleaning programs for our distribution pipes. If you watch the workers do this, you will notice that the water cleans up rather quickly.

How do you detect a major leak in the distribution piping system?

A major leak can be detected by the following:

  • 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. Any leakage that occurs within the boundary of your property is your responsibility and must be repaired at your own expense. Learn more about pipe ownership.

How is the inside of a pipe cleaned after fixing a broken water pipe?

After repairing a water pipe, the pipe is filled with water containing a large amount of chlorine. Holding this water in the pipe kills all the germs.  A chemical is then added to react with the chlorine and destroy it before the water can be flushed out of the pipe and discharged. Alternatively the highly chlorinated water must be discharged to an area where it will not impact 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.

Why is some drinking water stored in large tanks high above the ground?
Storing water in large tanks above the ground ensures that there's enough water pressure and water volume to fight fires. Another reason for this type of water storage 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 use regular inspections and sampling to ensure water quality in tanks.
I have a water softener, why do I still get spots on my bathroom tile?

All water contains dissolved non-toxic minerals, such as:

  • Calcium
  • Magnesium
  • Sodium
  • Sulfate
  • Chloride
  • Bicarbonate

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 hard water because they interfere with soap suds, making washing difficult. A water softener trades the calcium and magnesium for sodium or potassium, so the water leaving the softener has no calcium and magnesium and more sodium or potassium. A reverse osmosis unit (instead of a water softener) actually removes minerals from the water, not just exchanges them, and you would not experience the white film left by minerals in the water.

How much water does a person use each day?

Total water use varies depending on lawn watering and whether a home has a washing machine and a dishwasher. Because of other uses in a community, the water supplier pumps much more water than is just used in households.

In Canada, average total home water use is about 60 gallons for each person per day. The use for drinking water has been estimated at about 1.5 litres (1.5 quarts) each day.

Where does the water go when it goes down the drain?
The City of Cambridge uses 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 even larger pipes that connect various neighbourhoods and then flow to 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.
What activity in my home uses the most water?

Toilet flushing is by far the largest single use of water in a home. Canadian flush toilets use about 4 to 6 imperial gallons (18 to 28 litres). On the average, a dishwasher uses about 50 per cent 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 %

Since 1996, the Ontario Building Code has required all new homes to have only low volume toilets installed.

Should I bother to fix my dripping water faucet?

Yes. Dripping faucets waste a lot of water over time, which means you are also paying for this wasted water.

Water quality considerations for re-opening your building during COVID-19

As a building owner and operator, you are responsible for the water quality in your building and should understand what could happen when water is left stagnant. The longer the building has low water use, the higher the risk for water quality issues. During COVID-19, reduced or no water use in buildings may present health risks. Here is some helpful information for reopening your building’s water supply.

Building Re-occupancy Fact Sheet

Important steps for reopening building water supply

Water quality concerns from prolonged stagnation

When the water is not used, the disinfectant in the water dissipates and may result in growth of microorganisms in pipes and fixtures. Disinfectant is used to prevent micro-organisms (such as Legionella) from spreading, preventing diseases. Stagnant water may dissolve toxic metals (lead). 
Re-opening considerations 

Prepare your water management plan:

  • The best immediate action is to flush the entire building
  • Inspect mechanical equipment to ensure proper function
  • Clean all fixtures
  • Develop a water safety plan to maintain/restore water quality

In most cases, flushing buildings with water that has normal chlorine levels is sufficient for cleaning the water system.

How to flush a large building 

The American Water Works Association (AWWA) provides guidance to COVID-19 Shutoffs and Return to Service.

  1. Remove or bypass point-of-entry treatment units prior to flushing.
  2. Take steps to prevent backflow or the siphoning of contaminants into pipes.
  3. Flush to maximize water flow.
  4. Run enough water through all fixtures and taps, removing aerators when possible.  (10 to 30 minutes for each, depending on water velocity). 
  5. Flush the cold water lines first, then the hot water lines. Flushing should go from the shortest to longest zone to ensure optimum water quality. 
  6. The flushing process should go from the shortest to longest leg/zone to ensure optimum water quality.
  7. Replace all point-of-use filters, including the filter in refrigerators. 
  8. Additional precautions may be needed. 

Flushing Responsibilities 

  • The building owner is responsible for the cost of recommissioning, including the cost of water needed for flushing
  • Initial flushes of stagnant water may release high concentrations of chemicals and contaminants. Flushing should be conducted in a way to minimize splashing / aerosols.
  • Consider hiring an expert such as plumbers or engineers to design and complete flushing plans. 
Other recommended steps 

Site Specific

  • Building water management plans should reflect the building’s unique characteristics. Common elements include regular flushing and thermal regulation.
  • Flushing is a best practice, is easy and has proven water quality benefits, so should be done periodically.
  • If you can measure water quality, it’s important to measure chlorine concentration at the supply and at the furthest tap in each zone. Some aspects of the building are site specific and will affect the volume, order and time needed to flush each tap. Protocols may require access to plumbing plans or drawings and building personnel who have knowledge of the system design.
  • Legionella management typically relies on thermal control or onsite disinfection. Hot water systems should continue to operate to minimize potential legionella growth. If water heaters and pumps are shut down to save energy, this control will no longer be available. Consider hiring an expert to restore the water heating system.
  • If there is a strong reason to believe the building’s water quality is not restored with flushing, contact your local municipal water utility (contact information below).


  • When informing occupants, communication should be tailored to individual situations and be accessible to all building occupants (simple language) and communicate risk factors 

Contact Information

City of Cambridge Public Works




The Water Division is committed to:

  • Providing safe sustainable drinking water to our residents and businesses;
  • Complying with applicable legislation and regulations as related to the provision of safe drinking water;
  • Maintaining and continually improving our Quality Management System (QMS).

One dollar of water

Watch our short video to see what $1 of water looks like.