SCADA Solutions Since 1981





Expansion continues at Holley-Navarre Water System, Inc.

Holley-Navarre Water System, Inc. (HNWS) ramped up operations in 1970. Since its founding, HNWS has expanded and upgraded their services to meet the growing needs of its members.† Today, HNWS provides water and wastewater treatment services for more than 14,000 customers.

In 2002, DFS was selected by HNWS to provide a SCADA System for its water wells and wastewater lift stations located in Navarre, Florida. Over the last decade, the original HNWS SCADA System has experienced considerable growth and expansion.

HNWS recently awarded a contract to DFS to replace the SCADA equipment currently utilized for their Fairpoint Water System. With the phase-out of the existing Citect Software/Siemens PLCs/Integra radios, HNWS is looking forward to improved performance, reliability and the customer support thatís provided by DFS.

The scope of work under this latest contract includes a new dedicated polling loop, system partitioning, and 14 PLC-based RTUs for the process automation of water wells and motor operated valves. Below is a glimpse of the automation features to be performed by the system.


The Well automation will operate in a lead/lag fashion based on the water elevation/pressure at the Fairpoint EST RTU. Two backup strategies will be provided to ensure water availability.

In the event of a failure at the central site (i.e. lightning damage), the Fairpoint EST RTU/PLC will resume radio communications with the Well RTUs and transmit its EST level.

Each water well RTUís local pressure transducer will be used to determine an exceptionally Low or High pressure situation and operate the pump accordingly. Both the Low and High pressure function will have separate resets and each can be enabled or disabled independently.


The Motor Operated Valve (MOV) automation will operate based on each valveís local flow meter, as well as have the ability to receive a remote-control from the central siteís Hyper SCADA Server (HSS). Under normal operations the MOV will be automatically modulated by the RTU/PLC to maintain a user-specified flow-rate (set-point). A dead-band setting will be available to prevent excessive modulation of the valve. Additional set-points will be provided for Daily Allotment Permitted, High Pressure, and Low Pressure.

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