Over the past several years, the City of Orlando Public Works Department has installed extensive high-technology upgrades and automation systems in its three wastewater treatment plants, vastly improving the capacity and efficiency of its operations. Orlando’s 320-acre Iron Bridge wastewater plant, for example—the largest of the three—was originally built in the 1980s to treat about 5 million gallons of wastewater per day. But after several modifications and upgrades, it can now treat and reclaim up to 40 million gallons in that same 24 hours.
 
Yet despite that growth, the plant today can be operated with significantly fewer employees than in the past, says Guy Mecabe, wastewater system manager. Indeed, Iron Bridge has gone from more than 20 operators needed to run the plant just a few years ago to as few as three per shift today, Mecabe says.

The primary driver for that productivity gain has been the automation system put in place beginning in 2005. Based on programmable logic controllers (PLCs) linked by Profibus and Industrial Ethernet networks supplied by Siemens Industry Inc., Alpharetta, Ga., the automation platform controls everything from the flow of electricity to the amount of reclaimed water being discharged from the plant. Operators can monitor and manage the entire operation from any of 10 on-site Siemens human-machine interfaces (HMI), or remotely using Siemens WinCC supervisory control and data acquisition (SCADA) software.

Video connection
But in addition to the extensive amount of real-time process data made available to operators through the HMI/SCADA system, the displays also include a still somewhat unusual capability in the industrial space—access to real-time and recorded video. With a single mouse click, operators can access live, streaming video from any of 18 digital Internet protocol (IP) video cameras mounted in strategic locations throughout Iron Bridge and the other two plants, known as Water Conserv I and Water Conserv II. Traveling over the same broadband fiber optic-based Ethernet network as the process data, the live video feeds can appear as pop-ups directly on operators’ HMI screens, enabling them to keep tabs on what’s happening across the facility.

“We actually started looking into video about three years ago,” says Mecabe. “We were looking for something that would handle both the security aspect of video surveillance and also the process aspect.” Because plant managers knew that they would be operating with significantly fewer employees, “we wanted to give our operators some eyes and ears out in the field,” he explains.

On the security side, the digital video system replaces an earlier analog closed-circuit TV (CCTV) system. IP video cameras are located at all three plant front gates, enabling control-room operators to handle gate duties while also monitoring operations. When a vehicle pulls up to a front gate, the driver pushes a button, signaling the control-room operator to bring up the gate camera video pop-up on his or her HMI screen. The operator can control the camera to zoom in on the vehicle license plate and the driver’s face, and can carry on a two-way conversation over the network using the camera’s audio capability, finally opening and closing the gate through the HMI system to allow vehicle passage. Video is archived on servers at each site for access later as needed.

Other cameras are used to improve process operations. At Iron Bridge, for example, four cameras are trained on the plant’s sludge processing operations, where solids are separated from the water and carried on conveyor belts through a building and up an incline to be dropped into trucks. Operators in an upstairs control room can switch the sludge flow from one conveyor to another, and on some occasions in the past, “they switched it when there wasn’t a truck there, so it piled up on the floor and made a big mess,” Mecabe says. But with the IP video cameras in place, operators can now check to be sure that a truck is in position before making the switch. “Since we put in the cameras, we haven’t had any messes.”

Mecabe also points out that having the video integrated into the WinCC SCADA system has been an important time saver, given the plants’ reduced staffing levels. “The video gives these guys the ability to quickly check and see something, rather than having to jump in a truck and drive out,” he observes.

The Orlando wastewater plant system is one example of an emerging industrial trend involving wider use of digital video technology for applications ranging from industrial security and safety to compliance, process monitoring and ...