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Abbey systems SCADA system & Swampfox RTUs standardise Rotorua’s wastewater control and alarm system.

About Rotorua District Council

Rotorua is found on the shores of Lake Rotorua in the central North Island of New Zealand. The surrounding area is a geothermal wonderland, with geysers, boiling mud pools, and steaming craters, accompanied by the pervasive smell of sulphur. Rotorua is also a showcase of Maori cultural activities, a centre for tourism and a place of extraordinary natural beauty. It is surrounded by volcanoes, lakes, parks and recreational areas, and is a great place to visit for both locals and tourists.

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Challenge

The original RDC wastewater Telemetry Syste had developed 3 differnet control methodologies, as technology had evolved. Some pump station sites used Float control, others Probe control and the newer sites used Analog control. All three site types were also wired differently which led to Engineering and Operational difficulties.

Solution

Abbey Systems successful solution was to standardise and simplify the SCADA hardware, programs and methodologies used at each of the Council watewater pump stations. A complete communications system was installed and Alarms and automated reports give Council Engineers tools to target maintenance, before they become an issue.

Results

Abbey Systems installed a complete SCADA system comprising Telemetry Server and 3 repeater radio network to communicate with each wastewater pump station. These sites are all equiped with a Swampfox RTU that controls the site pumps, depending on the measured well level, and also collects site performance data; inflow, outflow, energy use and well level, which are timestamped and returned to the Telemetry Server for management of any alarms, reporting and planning use.

Abbey systems supplied and installed a turnkey SCADA system for the monitoring and control of the Rotorua District wastewater network.

 

The challenge

When the local Council needed a well proven SCADA system to replace their old system to manage the city’s wastewater network in 2005 they chose Abbey Systems products. From the beginning the Rotorua network was designed for standardization and a high level of automation and reporting.

Rotorua District Council's 68 sewage lift stations are fitted with Swampfox RTUs, which communicate via a new UHF radio network to an Abbey Systems Telemetry Server and iFix HMI. The advantages in using Abbey Systems RTUs include; programs can be modified at the base station and downloaded to the site, and pump station programs can interact with other pump stations and cater for sudden inflows, balancing flows into the treatment plant.

The solution

Pump automation is controlled by logic programs created and tested at the Powerlink Master and downloaded via the radio network to the RTUs. The logic is designed to minimize the number of pump starts, letting them operate at higher average well heads for greater efficiency. The programs also cater for rapid inflow changes, balancing inflows to the treatment plant. Ultrasonic level transducers connected to each Swampfox measure the level of each well and control pump operation.

Automated reports are created weekly in spreadsheet format and sent to a network server. Council Engineers use these, along with Hilltop software, for ‘flow modelling’ and to target pump maintenance, allowing rapid identification of poor performers.

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The result

Each Swampfox RTU datalogs its pump station's performance. As the station operates, the inflow, outflow and power consumption are calculated, timestamped and stored to memory for later downloading over the communications network to the Telemetry Server. Ratios of power consumption vs outflow can be used to evaluate pump performance and target maintenance.

Abbey Systems Telemetry Server also sends Alarms out to pagers and cell phones, where Operators can acknowledge them. Recently this system was expanded to include the Wastewater Treatment Plant Alarms.

The SCADA replacement program took 24 months from start to finish.

Key benefits

  • All pump stations use an Analogue Ultrasonic transducer for well level control and a standard suite of 2 pump programs is used at each site.
  • Swampfox RTUs at all 2 pump sites are wired the same way
  • Swampfox RTU controls the pump start & stop, duty changeover and pump 2nd starts, saving the added cost of a dedicated level controller or PLC.
  • Performance stats for each site are datalogged, including pump run hours, # starts, inflow, security, and retrieved daily by the SCADA Master.
  • All RTUs are “conformally coated” for protection against Rotorua's high level of hydrogen sulphide gas in the atmosphere and methane from pump station activity.
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Project snapshot

Case Study Rotorua Wastewater Network
Client Rotorua DC
Contract 04/132
Installation Date 2005 - 2007
Number of I/O 8,100
Number of RTUs 68
Communication methods UHF and VHF radio
Electrical Contractor Townley Electrical Ltd
Communications Contractor Alcom Communication Services

 

Site network diagram

Site network diagram

Location information

 

Contact us now to learn more

About Arthur D Riley

Founder Arthur D Riley was an engineer renowned for his entrepreneurial spirit, something ADR continues to embody as providers of field-smart technology. This means we are always there for our customers, with technology and expertise that keeps operations running in the field. From high voltage power distribution, water revenue metering and system control, to data acquisition and parking management systems, ADR offers a proven, field-smart solution backed with technical expertise.

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