During the cold of winter, water pipes can freeze. When a frozen pipe is experienced, it can either be within the home or outside, within the buried water service. During extreme cold weather, internal household pipes become susceptible to freezing due to inadequate heating or poor insulation, while the buried water service becomes susceptible to freezing due to frost penetration in the ground. In either case, when pipes freeze you can be left without water for long periods of time.
Why pipes freeze
Most water services in the City of London are buried at least 1.7 metres deep for protection against frost. A small portion of water service lines, however, are less deep due to road reconstruction, improper installation technique, or are in close proximity to storm sewers or private drain connections (pdc’s). Extremely cold temperatures increase the risk of the frost penetration reaching a depth that will freeze these water services. In February 2014 and February 2015 London experienced conditions that caused these susceptible water services to freeze. Extreme cold temperatures can also cause household pipes to freeze.
Water entering London’s distribution system comes from Lake Erie and Lake Huron. With a surface water source comes fluctuating water temperatures due to seasonal changes. London’s drinking water temperature fluctuates between 1 to 22 degrees Celsius, with the coldest water temperatures being experienced in February, and the warmest temperatures in September. During February, with the water temperature so close to the freezing mark, it takes very little exposure to sub-zero temperatures for it to freeze. That is why it is important to make sure your household pipes are not exposed to colder air during winter months.
This is the depth in which frost is present in the ground. In London, frost depth usually does not reach the level of our buried water infrastructure. However, during extremely cold conditions, such as those experienced in February 2014 and 2015, frost may reach these levels.
In early spring, the air temperature is warmer, but frost is still deep in the ground. As long as the air temperature continues to drop below freezing at night, the frost penetration will remain in place.
When the ground surrounding the water service lines becomes frozen, it will cool the already cold water in the pipes. When the water stops moving, as when water is turned off overnight, the temperature can lower quite quickly and freeze the water. If your water service is susceptible to freezing it is important to keep a minimal amount of water running during these events; it keeps warmer water moving through the frost zone.
Preventing Frozen Pipes
Many cases of frozen pipes within the home can be prevented through proper heating and insulation. Follow these simple tips to protect your water pipes:
- Wrap foam pipe insulation around the water pipes most susceptible to freezing (those pipes along exterior walls, within crawl spaces or in cellars).
- Open kitchen, bathroom and laundry cabinet doors to allow warmer air to circulate around the plumbing. If piping is located next to exterior walls, leave the cupboard doors under your kitchen and bathroom sinks open. Please take care to remove household cleaners and other items that could harm children or pets while the cupboard doors are open.
- Shut off and drain pipes leading to outside faucets.
- Seal air leaks in your home and garage, especially in areas where pipes run.
- If you’re going away, talk to your insurance company about what you can do to protect your home from frozen pipes and leaks while you’re away.
- If there are water supply lines in the garage keep outside garage doors closed, or if possible, shut off the supply of water to these lines.
- Commercial water customers need to prepare for cold nights as well. Protect fire lines by wrapping any pipes that are exposed to cold temperatures.
Preventing Frozen Water Services
If your private side water service has frozen in the past, the best solution may be to lower your water service to a depth that cannot be penetrated by frost. The City of London requires new water services to be buried between 1.7 to 1.9 metres.
If the water service to your property was one of the 711 services that froze within the public right-of-way in 2014 or 2015, the City is systematically remediating these by either lowering or insulting the service. This infrastructure is owned by the City, therefore, there is no cost associated with this remediation to the property owner. As of December 2017, only 130 properties were still in need of water service remediation.
What to watch for
We are here to help. Not every household is at risk. Please call us at 519-661-4739 if:
- you have a history of frozen water service, or
- if you are experiencing unusually low water pressure.