SOUTHBRIDGE WATER TREATMENT PLANT
SCADA IMPROVEMENTS
town of southbridge, massachusetts
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:
wz Maintaining plant operations during construction
m Replacing the existing redundant PLC-5 processors with new redundant PLC
processors
= Consolidating or simplifying process contro! 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
w= Updating the panel view or HMI at Filter 1 to duplicate the SCADA computers
for redundancy
m Reviewing internet security for communication to off-site monitoring locations
m Assessing and proposing upgrades to the alarm notification, data logging, and
remote access device software
Construction of the upgrades was completed in the summer of 2015.
westonandsampson.com
replace redundant
plc system for plant
process conirol
# increased
communication speed
between ple and
devices by converting
to ethernet
eB increased memory in
pic system
a ethernet/ip ready for
future devices (i.e.,
“plug and play”)
a upgraded plc and
scada computers and
software
client contact
Heather Blakeley, PE
Acting Director
Town of Southbridge
Department of Public Works
Southbridge, Massachusetts
508-764-2237
Weston(&)Samason
