Alexandria residents paid $340,000 over the past two years for recycling bins fitted with microchips that were supposed to help ensure that the city was recycling as much trash as possible. So far, they've gotten nothing for it.

City officials, who required residents to pay $9 a year more for the new computerized bins, say that though they have monitored the trash-handling habits of 19,000 households for two years, so far the program has prompted no changes or actions to increase recycling in the city.

When the city instituted the program in 2010, officials said they would use the data collected from radio frequency identification tags inside the bins to monitor which blocks were actively recycling and which needed to be coaxed to do better. If a neighborhood was found to be falling short in its recycling efforts, city officials intended to speak to those residents to encourage them to recycle more.

So far, the computerized bins have helped the city determine that "we capture as much recycling material as possible," and that Alexandria is on track to become "a leader in recycling," said Alton Weaver, chief of Alexandria's Solid Waste Division. But the city hasn't identified any underperforming neighborhoods or done anything to encourage residents to increase recycling in those areas.

The city still needs to do more "data gathering," city spokeswoman Kathleen Leonard said, before it begins contacting underperforming recyclers through mailers, online social media and neighborhood meetings.

Alexandria residents initially complained about the new recycling bins because of the increased costs, though those complaints have tapered off, Weaver said.

The computerized bins were put in place about the time the City Council was adopting an Environmental Action Plan that set long-term goals for the city regarding transportation, green buildings and solid waste, among other areas.

Alexandria recycles 49 percent of its trash, which is higher than benchmarks set by the state (25 percent) and Environmental Protection Agency (35 percent). City officials, however, hope to boost that rate to 60 percent.