Some $100 million in countywide emergency communications upgrades are on the line next week.

County voters on Tuesday will consider Proposition E-911, which seeks the establishment of a 0.1-percent sales tax to improve area first responders’ outdated radio systems as well as the county’s 911 call centers and emergency sirens.

As proposed, the sales tax would fund an $80 million countywide interoperable digital radio system.

The system would allow all police, firefighters, ambulance, public works personnel and other emergency service workers to communicate with each other at a disaster scene.

In addition, the new system would allow emergency responders to meet a Federal Communications Commission requirement to narrow their frequency bands by the end of 2012. St. Louis city, Jefferson County and St. Charles County have similar systems in place.

The sales tax also would fund a $10 million upgrade to the county’s 28 emergency 911 answering centers. New digital technology would provide emergency responders with the geographic location of all 911 calls made to the centers, including those made from cell phones.

Finally, taxpayers would fund an additional $10 million overhaul of the county’s emergency siren system.

The effort would repair 16 currently inoperable sirens, install new sirens in areas of north and west county and potentially upgrade other sirens to provide more localized alerts and voice commands.

The new sales tax — which has no sunset date — would generate an ongoing revenue stream of roughly $16 million a year, according to the county’s Emergency Communications System Commission, or ECSC, which requested the ballot measure.

At 0.1 percent, an individual would pay 10 cents tax on a $100 purchase.

As proposed, the tax doesn’t exempt food or medicine purchases. However, if Missouri lawmakers pass legislation next year calling for those sales-tax exemptions, the emergency communications sales tax’s annual revenue would decrease to $13.6 million from $16 million.

The ECSC would have sole control of monies generated from the tax but would be required to request an annual appropriation of those funds from the County Council.

If voters approve Prop E-911 next week, the county likely would issue $100 million in certificates of participation, or COPs, to obtain up-front funding to begin building the new communication infrastructure, which is expected to be in place by 2012.

Those COPs would be retired in 20 years, but the county will need the ongoing revenue stream to maintain the new system and keep the technology up-to-date. However, the ECSC has estimated it would only need $4 million of the $16 million annual tax revenue for maintenance once the system is constructed.

“A $4 million operating budget is what we think in terms of the ongoing maintenance of it. That’s still something that’s a work in progress,” Des Peres City Administrator and ECSC member Doug Harms said during a Prop E-911 press conference last week. “Clearly the law lets the commission and the County Council reduce the amount of the sales tax if it’s appropriate at the time … I have every bit of confidence in the voters of St. Louis County and the people they elect that they’ll reduce the tax as they can or as they need to to support the system without generating additional funds that they don’t need.”

E-911 supporters say the sales tax — and the timing of its passage — is critical because special digital radio frequencies currently reserved for the county will be available only until late 2012.

In addition, proponents contend that it’s more cost-effective for the county — not individual public safety entities — to fund the communications upgrades.

A number of well-known county officials and organizations have endorsed the ballot measure, including Prosecuting Attorney Robert McCulloch, county Police Chief Tim Fitch, the Metro transit agency, the St. Louis County Police Commission, the East-West Gateway Coordinating Council of Governments, International Association of Fire Fighters Local 2665, the Missouri Department of Public Safety and the St. Louis County Municipal League.

“Technology has really blown past us,” McCulloch said during last week’s press conference, surrounded by dozens of police and fire officials from around the county. “The technology we have in the communications system in St. Louis County is World War II vintage. We have to move that up so that every department can communicate …”

The County Council voted 5-2 in May to place Prop E-911 on the ballot. Sixth District Councilman Steve Stenger, D-south county and 7th District Councilman Greg Quinn, R-Ballwin were opposed.

Stenger has said that he supports a county communications upgrade but believes a sales tax isn’t the way to fund it.

He told the Call in May that the county should seek federal stimulus money or utilize some of the $13 million expected annual revenue from Pinnacle’s River City Casino in Lemay, which is slated to open in January.

“We’ve got a casino that’s going to be coming in January here and that casino money is going to generate about $13 million to the county coffers,” Stenger said. “So why not use that $13 million rather than raise sales taxes further?

“There’s ways to raise this revenue without raising taxes. I have a great way. How about the stimulus plan? Why not apply for some stimulus money for this? If not the casino (revenue), why not stimulus money? Why does it have to be the St. Louis County taxpayer economic stimulus plan? That just doesn’t sound right to me.”

In south county, the Tesson Ferry Township Republican Club also has come out against Prop E-911.

“The Republican organization believes that the financial hardship to the hard-working taxpayer during a recession does not justify using tax revenue for this purpose,” the group said in a statement. “There is no sunset on a tax increase; it could go on into perpetuity. Furthermore, the regressive nature of a sales tax is harmful to those on lower incomes.”

Meanwhile, the Mehlville Fire Protection District — the largest fire district in the county — remains neutral on the issue.

Administrative Fire Chief Tim White told the Call last week that the district’s radio system already is prepared for the FCC’s narrowed frequency mandate and would be “OK” regardless of whether Prop E-911 passes next Tuesday.

“Luckily, the Mehlville Fire Protection District is prepared for narrow banding,” White said. “All of our radios are compliant to meet that need as required by the federal government that’s going to be coming down the pike. So we’re good to go.”