The Clermont County Water Resource District serves one of the fastest-growing counties in Ohio, utilizing 105 wastewater lift stations, eight wastewater treatment plants and two wastewater equalization basins. In an ongoing effort to ensure reliability and create efficiencies, the WRD recognized the shortcomings of its landline-based telemeter/dialer system. A primary concern was that notification of critical alarms was sent to a printer, yet when the plant operator was not near the printer, alarm notifications were received late or missed completely.
The Clermont County WRD engaged Rawdon Myers to implement a wireless SCADA system with a cell modem connection. The goal was to create a secure virtual private network (VPN), static I/P addressing and expandability. Ensuring stability and accuracy throughout the system was a principal objective.
During the 18-month project, the WRD retrofitted new PLCs into each remote terminal unit (RTU) throughout the county and Rawdon Myers provided the program within the PLCs, including a template that allowed the client to choose a two- or three-pump station. The system uses a public cell connection with a very secure VPN within.
There are 114 remote wastewater sites locally monitored by Allen Bradley Micrologix 1400 PLCs, each connected to a Sierra Wireless GX400 cellular radio. The main server runs VTScada software. There is a VPN with dedicated static I/P addresses for each site. Numerous security protocols are in places, such as SSL encryption, firewalls and password protection. Multiple redundancies and power sources are in place, including a fail-over internet connection. Voice, email and text alarms are sent via landline and/or internet client emails.
The new SCADA system has brought significant advantages to Clermont County WRD.
- Elimination of more than 500,000 pump starts per year
- Real-time well level monitoring, reducing after-hours callouts by over 60%
- Daily reports allowing for correction of potential problems before they become critical repairs
- Ability to access and program PLCs from remote locations and make real-time process changes
- Significant cost-savings by using a cellular-based system
“Rawdon Myers has helped keep our critical operations going by making themselves available after hours. They have the knowledge and experience to handle difficult automation programs – ones that others are reluctant to take on. Rawdon Myers has improved our operations and created electrical/operating efficiencies by automating certain operator duties, freeing the operators for more needed areas and reducing run times/ energy consumption on equipment. Rawdon Myers has also given helpful advice on when to upgrade outdated automation equipment before repair parts become scarce and expensive.”
— Giles Thrift, Operations Supervisor, Wastewater Treatment and Compliance, Clermont County, OH Water Resources Department