WATERLOO -- With Canada testing its emergency alert system this week, officials in Waterloo Region are reminding residents of similar community alerts designed to keep people safe at municipal and regional levels.

Many Ontarians were spooked by a noisy alarm on their cellphones at 12:55 p.m. Wednesday when Canada's emergency alert system conducted its bi-annual testing program.

Alert Ready simulates an emergency alert on TVs, radio and mobile devices across the country. The service is used in the event of a life-threatening situation and Canadians do not have the option to opt out of the tests or alerts.

Woolwich Township has had a fully operational emergency siren since 1989.

"The reason why it's there is for the chemical industry that's there in Breslau," Woolwich's community emergency coordinator Avril Tanner told CTV News.

The 32-year-old alarm is tested weekly and has been used twice for chemical emergencies in the mid-2000s and also for a tornado warning in 2017.

"The sirens are really our quickest form of notifying residents and so, for chemical release or tornado warning, those emergencies happen very quickly," Tanner said. "It just notifies our residents that something is happening and they need to get indoors and wait instruction."

The siren is in addition to the Alert Waterloo Region system that has been in place since 2019. The service requires registration in order to get alerts and costs the region $170,000 to run over three years.

So far, 20,000 people have signed up for the alerts.

"Those folks that are within the floodplain areas are notified through the Alert Waterloo Region system based on their local community emergency management coordinator," said Diane Schofield, manager of emergency management for Region of Waterloo.

Hundreds of thousands of people in the region are not subscribed to the service. Schofield said measures have been put in place to make the alerts available to more residents.

"If you receive a hydro bill, you can receive an Alert Waterloo Region notification through to your landline," Schofield said.

Anyone without a landline can opt to receive alerts on their cellphone or by email.