Normal: Not Your Typical Water Department
The Town of Normal, IL, Water Department recently completed replacement of an out-dated Supervisory Control and Data Acquisition (SCADA) system with a new PC-driven, spread spectrum system.
The Normal municipal Water Depart-ment employs 28 full-time employees and serves around 13,000 consumers with an average consumption of 4.5 mgd. The Town's maximum available daily supply of water is 8.5 mgd.
Prior to its SCADA replacement process, the town was operating a system with outdated remote terminal units (RTUs) which performed minimal SCADA. The system had a large footprint, was very complicated to understand, expensive to service and difficult to repair.
In the neighboring town of Bloomington, IL, is a systems integration firm called SCADA-ware, which specializes in the design and implementation of open-architecture control systems and PC-based SCADA systems. Having recently completed the Rock Falls, IL, SCADA replacement, SCADAware's president Rick Caldwell began conversations with Normal Water regarding overhaul of the system's old RTUs and their corresponding components.
The management team at Normal Water felt that a new system should be built from the ground up to suit its operational needs. The team wanted self-sufficiency with its new solution and the ability to create, install, maintain and repair its new technology with minimal outside help. And, like many municipal SCADA projects, the department was expecting to purchase a tried-and-true, PLC-based, licensed, fixed frequency SCADA system.
In an effort to control costs, and to satisfactorily address Normal Water's desire for self-sufficiency, Caldwell recommended an atypical, PC-driven, license-free, frequency hopping spread spectrum solution, which is ultimately what the Town of Normal purchased.
New System
The Town of Normal Water Depart-ment now uses a primary and secondary server within its water treatment plant for HMI and PC-based control. The computers collect and monitor data from all of Normal's wells, tanks and lift stations via a Locus wireless serial network, with data rates of 57,600 bps as compared to the previous 300.
Wago I/O PFCs (programmable field couplers) allow personnel at the water treatment plant to make adjustments and activate controls in their system. A Sixnet Ethernet-to-serial converter is used at the water department site to convert the incoming serial data to Ethernet so the data can be accessed on the plant's LAN.
SCADAware's software features a simple-to-use graphical user interface allowing access to data as well as visual indicators of possible problems.
The new network allows water department employees to build and modify the system to suit their needs. Its interdependent modules are easy to diagnose and affordable to fix or replace. The new network also will accommodate future expansion to include sensors and other measures deemed necessary by vulnerability assessments.