Telephone Emergency Warning System Up And Running



The County of San Bernardino has added a new level of protection for county residents living in fire and flood danger zones. The County's Telephone Emergency Notification System (TENS) is fully operational and stands ready to warn county residents in high-risk areas of impending floods, fires, and other life-threatening situations. The system, formerly referred to as "reverse 911," can dial all of the known phone numbers in a chosen geographical area and provide those who answer with pre-recorded emergency information.

The Board of Supervisors in January directed that the system be created and provided $169,700 in funding. In less than a month the County had reached an agreement with Tennessee-based Dialogic Communications Corp. to develop the system. It took much longer, however, for the County to receive telephone number data.

The system has been undergoing testing for the past several weeks, and could have been used — if necessary — during that time. "At this point we can say the TENS system has been fully tested and is now officially ready to help the County reach out and provide emergency warnings and information," said Board of Supervisors Chairman Dennis Hansberger. "This system will help us reach more people more quickly than any other method," said Supervisor Paul Biane.

The system currently covers an area bounded by the Los Angeles County line to the west, state highways 18, 247, and 62 to the north and east, and Interstate 210, state Highway 30, Interstate 10 and the Riverside County line to the south. It encompasses all of the county's mountain communities and all of Hesperia, Phelan, and Piņon Hills; the northern portions of Upland, Rancho Cucamonga, Fontana, Rialto, and San Bernardino; most of Highland and Yucaipa; and portions of Redlands, Yucca Valley, Victorville, and Apple Valley. The system can direct alerts to the entire coverage area, or to identified portions of the area.

The County's intention is to have the system available in these areas for a year, evaluate it, and decide how to proceed. The Sheriff's Department has the authority to activate the system at the request of the incident commander for a particular emergency. Those County agencies involved in use of the TENS system would be the Sheriff, County Fire, Public Works/Flood Control, Public Health, and the Office of Emergency Services.

Other details about the system:

  • There are currently 283,629 phone numbers in the system. Phone numbers will be updated quarterly.
  • The system can simultaneously call 500 phone numbers and will allow a phone to ring six times before hanging up. The system can leave messages on answering machines. Each completed call will cost the county 25 cents.
  • Unlisted numbers are part of the system. Cellular and other wireless phone numbers are not part of the system. In the event of an electrical outage, residents should have at least one traditional, non-cordless phone that relies only on a telephone jack — not an electrical connection.
  • Recorded messages will include a phone number for the public to call for additional information. Residents are urged not to call 911 for additional information after being contacted by the TENS system.


The County reminds the public that the TENS system is not intended to reach everyone who might be affected by an emergency. People with new phone numbers, people who are not at home when the system is used, and people who do not answer their phones will not receive TENS warnings. Because of this, the County does not plan to scale back existing emergency procedures because of the presence of the TENS system. Depending on the nature and scope of the emergency, the County will continue to:

  • Communicate with residents door-to-door, through the Emergency Alert System, and through the news media.
  • Post emergency crews in threatened areas.
  • Conduct community meetings and produce and disseminate written emergency information.
  • Take other measures as necessary.


The preceding information is from a press release issued by County of San Bernardino, issued August 31, 2004.

Created Thursday, September 16, 2004