Evaluation, Design and Construction for WTP SCADA Upgrades
The Town of Southbridge, Massachusetts selected Weston & Sampson to perform engineering evaluation, final design, and construction services for upgrades to their Water Treatment Plant (WTP) SCADA system. The existing SCADA system at the WTP consisted of aging redundant PLC-5 processors, aging computers, out-of-date software, and varying levels of communication and control at remote control panels. Since the PLC-5 was an older piece of equipment, some of the components associated with the system were unavailable for replacement.
In addition, the older PLC-5 systems had no free memory, a condition that was forcing the town to make process control modifications within the existing SCADA computers. The PLC-5 processors only controlled two of the three filters at the WTP. Filter 1 had been previously updated with a new SLC 5/04 during improvement work designed by Weston & Sampson, but due to the issues with the PLC-5 processors, it could not be easily integrated into the overall plant operations.
The SCADA improvements for the project included:
- Maintaining plant operations during construction
- Replacing the existing redundant PLC-5 processors with new redundant PLC processors
- Consolidating or simplifying process control utilizing remote I/O
- Upgrading the existing serial and blue hose communication protocols with Ethernet/IP
- Updating SCADA software to the latest version on several computers at the WTP and remote locations
- Updating the panel view or HMI at Filter 1 to duplicate the SCADA computers for redundancy
- Reviewing internet security for communication to off-site monitoring locations
- Assessing and proposing upgrades to the alarm notification, data logging, and remote access device software
Construction for this project is occurred in Fall 2014.