A new outdoor severe weather warning system is expected to be installed in Jefferson County by spring 2026.
The system will include 101 sirens mounted on utility poles and two central control units, and together will alert people in unincorporated areas of the county about dangerous weather with a series of loud tones, said Warren Robinson, director of the Office of Emergency Management.
The Jefferson County Council voted unanimously Oct. 28 to award a $2,248,396.74 contract to ATI Systems Inc. of Boston, Mass., to provide the system. The county received seven bids for the project, and while ATI Systems wasn’t the lowest bidder, it was the best fit for the county, Robinson said.
“The outliers that were far cheaper than ATI were not covering nearly the same geographic area that the ATI bid has,” he said.
ATI Systems has provided Arnold with outdoor alerting services since 2007, according to County Council documents.
The cost of the system will be covered with the county’s capital assets funds in the 2025 fiscal year budget.
Robinson said work on the project will begin early next year.
County officials have a meeting with the company in December to discuss the project timeline in greater detail.
“This is something we’ve had our eye on for several years now,” Robinson said. “We are excited to start putting poles in the ground. We’re excited to be able to offer this to Jefferson County and its residents and visitors.”
County Executive Dennis Gannon said Oct. 28 that the outdoor warning siren project has been on the county’s wish list – the Capital Program and Strategic Plan – for many years, but has been on hold due to a lack of funding.
“(The system) was an on item on that list going as far back as 2022, and I believe even further than that,” he said. “I think, had we not kept it on our list, we would have never had a method or a plan to make it happen.”
Before awarding the contract for the system, an acoustic modeling study was completed in 2023, and it analyzed the best places for each siren, Robinson said.
The study cost $30,000, and the county received a federal Building Resilient Infrastructure and Communities grant that covered 75 percent, or $22,500, of the cost, and the county covering the remaining $7,500.
The county’s goal was to cover 2,000 or more people per square mile with each siren.
According to county documents, 94 of the sirens will be “tone only,” meaning they will not project recorded voices during emergencies. Seven of the sirens will have voice and tone capabilities.
“The majority of these (sirens) are going to be tone only because you can cover a larger geographic area with fewer sirens, just because of the way that the tone carries,” Robinson said. “We are going to have a handful of sirens out there that are also capable of voice, but those are going to be located at areas where we see large outdoor gatherings a lot of times – the Northwest Sports Complex (in House Springs), and the park over at the port right next to Kimmswick, as examples.”
Robinson said the voice and tone sirens will explain why the system has been activated during severe weather events and will provide instructions on what to do, such as finding the nearest shelter.
The system will be activated automatically when the National Weather Service sends out an emergency warning for an area, Robinson said.
The siren system targets people who are outdoors and have limited cell service or access to a telephone, he said.
“There are areas of the county that simply do not have good cell phone reception,” Robinson said. “If you’re in one of those areas, this is another potential way for you to receive a warning.”
Jefferson County 911 Dispatch switched its emergency notification platform from Code RED to Everbridge in October 2023. People who sign up for the service receive automated weather warnings issued by the National Weather Service on their cell phones.
“The outdoor warning system is not going to replace Everbridge,” Robinson said. “We still absolutely encourage people to use Everbridge, but this system is really going to come into play when they’re outside and away from their telephones or if they’re visitors in Jefferson County.”