Bookmark this page

Durham Region Public Alerting System
Frequently Asked Questions


Legislation – Why have a Public Alerting System

The Public Alerting System

System Details

Other Questions


Q. What is public alerting?

A. Alerting means warning the public, by means of an appropriate signal, that a nuclear emergency is developing.

An alerting signal means turn on your radio and TV for instructions on what to do. It does not mean evacuate.

Legislation – Why have a Public Alerting System?

Q. Is public alerting a legislated provincial requirement?

A. Yes. While the probability is low, the occurrence of a nuclear accident cannot be excluded, as the consequences could be severe. The Provincial Emergency Management and Civil Protection Act requires that the Province and designated municipalities have plans for emergencies arising in connection to nuclear facilities. The Provincial Nuclear Emergency Response Plan requires Durham Region to install a public alerting system that meets the provincial standard.

Q.What is the alerting standard, for the three-kilometre zone, as mandated in the Provincial Nuclear Emergency Response Plan?

A. The alerting system must provide, within 15 minutes of its initiation, warning to practically 100 per cent of the people in the 3-kilometre zones at that time, whether they be indoors or outdoors, and irrespective of the time of the year or day.

In the 10-kilometre zone, the public alerting system shall be installed to provide, within 15 minutes of initiation, warning on an area-wide basis to the population in all of the response sectors within that part of the Primary Zone. The term “area-wide basis” means that the alert system will cover the 3 to 10 kilometre areas, but does not presume that 100% of the people in that area will necessarily hear the signal.

The Public Alerting System

Q. What is the public alerting system?

A. The public alerting system consists of two components: sirens, which are an audible warning for alerting people outdoors, and an automated telephone dialing system for warning people indoors. The outdoor system has 14 sirens in the Municipality of Clarington and nine sirens in the City of Pickering.

Q. Where was the public alerting system installed?

A. Public alerting sirens were installed within three kilometres of the Pickering and the Darlington nuclear generating stations. This is part of the detailed emergency planning, close to the nuclear stations. In addition, the public alerting system will be extended to encompass the 10-kilometre nuclear planning zones. Indoor alerting is in place for the 10-kilometre nuclear planning zone.

Q. How does the public alerting system work?

A. In the event of a nuclear emergency, Durham Regional Police Service (DRPS) will activate the system on order from the Province. When initiated, a secure radio signal will simultaneously activate the outdoor sirens to warn the public. DRPS will also initiate activation of the automated telephone dialing system for indoor alerting. The Province will provide directions on what residents should do by radio and television messages, as well as through Facebook and Twitter.

Q. What do I do if I hear the alerting siren?

A. GO indoors. LISTEN to your television or radio for instructions. FOLLOW the direction from the Province on what to do.

System Details

Q. How were the siren locations identified?

A. The siren locations were identified based on population density, land use, terrain, background noise and acoustic surveys.

Q. Will the outdoor sirens continue to work during a power failure?

A. Yes, each outdoor siren has its own independent solar panel, battery back up and charger.

Q. When will the sirens be activated?

A. If there was a severe accident at either the Darlington or the Pickering nuclear generating station, which could result in a release of radioactivity, the Province will order that the public alerting system be activated. The sirens could also be used to alert the public to any other serious emergency, such as a transportation accident, involving the release of hazardous materials.

Q. How long will the sirens sound?

A. The sirens will sound continuously for three minutes.

Q. Is there a risk to my hearing if the sirens are sounded and I am close by?

A. No. The siren system is designed so that it will not damage hearing, no matter how close you are located to the siren.

Other Questions

Q. The nuclear stations have been in operation for 30 years. Why was the public alerting system installed recently?

A. The Province undertook several studies relating to nuclear emergency planning. Those studies indicated that planning for a severe nuclear accident should be considered. The Province, therefore, included the requirement for appropriate additional planning and preparedness measures to deal with the less probable, but more severe, accident scenario. This included timely alerting for the 10-kilometre zones. All stakeholders (province, Durham Region, area municipalities, Ontario Power Generation) agreed to proceed with the public alerting project.

Q. Can the system be activated for other emergencies?

A. Yes. The alerting system was installed to meet the requirements of the Provincial Nuclear Emergency Response Plan, but the system can be utilized for other large-scale emergencies. Areas with the alerting system are better protected for any emergency, such as a transportation accident, involving the release of hazardous materials.

Q. Are there any alternatives to sirens for outdoor alerting?

A. There are no viable alternatives to sirens for outdoor alerting. Siren systems are the worldwide standard for outdoor alerting of large populations for impending emergencies.

Q. Aren't sirens old technology?

A. While the concept has been in use for some time, the sirens by Acoustic Technology Inc. (ATI) are state of the art. The system uses two-way secure radio communications to activate, monitor and verify the operation of all sirens. The system demonstrates excellent performance, reliability and security against unauthorized activation and can provide status monitoring and verification of each siren site during a test or an actual emergency.

Q. Are sirens used in other locations in Ontario for emergency warning?

A. Yes. There are 10 sirens for nuclear warning in the Municipality of Kincardine, four sirens for nuclear warning in the Town of Amherstburg and 10 sirens for chemical warning in the City of Sarnia.

Q. Are similar alerting systems in use around nuclear stations in the United States ?

A. Yes. Public alerting in the U.S. is mandated to 10 miles out from a nuclear station. Outdoor sirens are used throughout the U.S. for warning around nuclear stations, and also for other potential emergencies, such as tornado warnings or earthquakes.

Q. How frequently will the sirens be tested?

A. The public alerting system will be tested twice per year, in the spring (May) and in the fall (October). Dates will be advertised, prior to testing, through the local newspapers and this website.

Q. Who is paying for the public alerting system?

A. Ontario Power Generation (OPG) operates the Darlington and Pickering nuclear generating stations and is providing all funding for this project, as a requirement under the Provincial Nuclear Emergency Response Plan.