Lower Keys property owners could pay anywhere from $2,000 to $3,800 more than what some of their neighbors have paid to connect to a state-mandated central wastewater system.

The Monroe County Commission on Monday is expected to approve a $6,500 fee, an initial assessment called a system development fee, for 10,000 homes and businesses from Lower Sugarloaf Key north to Big Pine Key to connect to the $194 million Cudjoe Regional Wastewater System.

The fee raises concerns about equity. The County Commission two years ago set a $4,500 fee for neighboring Big Coppitt Key property owners to connect to a central sewer system. Before that, it set a $2,700 fee for property owners on Conch Key and in Bay Point in the Saddlebunch Keys.

The lower fees were set when the county had access to more state and federal grant money, officials said.

The $6,500 fee is about what other Florida Keys governments are charging property owners. Marathon is charging about $6,400 and the Key Largo Wastewater Treatment District is charging $5,200.

"Equity is definitely a concern," County Commissioner Kim Wigington said, debating whether the county should set the $6,500 fee now or wait until later, when it knows how much supplemental funding it will receive to help property owners pay for connections.

Total connection costs could reach about $20,000. The remaining $13,500 could be covered by state funding or, in the likely absence of that, a 1-cent sales tax.

The county will know in the next year whether it can implement the sales tax, which would generate about $13 million a year. The Legislature must approve a measure to let county residents vote on the tax.

If the state Legislature meets in special session later this year and hears the proposal, the referendum could be in November. If the Legislature waits until its regular session in March, the referendum would be in November 2010.

The county could set the fee Monday, then increase it later if supplemental funding is lacking, according to Judy Clarke, director of county Engineering Services. But Wigington is not a fan of that idea. "I do not want to raise people's fees once they are set," she said.

The County Commission will meet at 2 p.m. at the Marathon Government Center, at Mile Marker 48.5 oceanside.

tohara@keysnews.com