Geographic Information Systems (GIS) are a cutting-edge technology used to manage geographic data in a digital environment. These are systems for storage, processing, interconnecting and displaying large volumes of information (spatial or otherwise), able to depict the information in the space (in the form of digital maps).
Specifically with regard to the scientific and business objective of water and sewerage networks, GIS constitute the basis for effective asset management, as they automate the function of technical services, improve the quality of services, reduce response time to customer needs and requests and curtail the company’s operating costs. GIS are a strategic planning and decision-making tool for the enterprise overall and for management in particular, which are particularly useful for future plans for water supply and sewerage networks.
As it monitors international developments in the field of water resource management, while working towards more effective management of water and sewerage networks and offering the best possible customer services, EYATH S.A.adopted this particular technology in 1998. Nowadays, with extensive in-house expertise and staff who are highly experienced in GIS technology, EYATH S.A. has managed to integrate it into its daily water supply and sewerage operations in real and business terms.
The company GIS provide EYATH S.A.’s personnel with uninterrupted technical information 24/7 (https://www.esri.com/esri-news/arcnews/winter16articles/greek-utility-company-operates-24-7-with-mobile-gis), accessed from the company’s central mapping server via smartphones or tablets, and effectively reducing response time, operating costs and customer disturbance with more effective customer service. At the same time, it is connected to the company’s other IT systems (customer service call centre), the ERP customer service system, consumption database, water sampling database, hydraulic network modelling, SCADA and others, with the ultimate aim of improving the services it provides.
The technologies incorporated by the GIS Department are based on the Map Server and Map Portal architecture, using a relational database management system (RDBMS) to store spatial data and interconnect with other IT systems, while technologies such as Mobile Mapping, Web Mapping & Desktop GIS technologically round out the company’s mapping infrastructure. EYATH S.A. uses ESRI mapping software.
Automation systems in Sewage Treatment Plant
At each wastewater treatment facility, the process is controlled and implemented by its own automation system. The automation system consists of local automation panels, the control centre and the communications network. The local automation panels include the programmable logic controllers, through which individual processes are controlled in automated or manual operation, either locally or remotely. There is a remote control system (SCADA) at the control centre which includes the SCADA server which monitors both processes and operational status of the equipment. It can also be remotely controlled, and offers the option of processing and storing the installation’s operational data and alarms. The communications network involves the connection of the local panel with the control centre, which is possible over fibre optics, cable or wireless connection in various types of communication, such as Ethernet, Profibus, ADSL, wireless Ethernet or GPRS. Briefly, each facility has the following:
1) Thessaloniki Wastewater Treatment Facility
The local automation panels at the Wastewater Treatment Facility include control screens from which to select operations and display processes, and operate and label equipment. At the Thessaloniki Wastewater Treatment Facility, the connection of equipment and field instruments with the PLC is often achieved over a network, such as Profibus. The control centre has a system of two redundant servers, in the form of client-servers, for supervision and control. The server for the maintenance programme is also installed at the control centre, along with the special programme collecting and processing data from the facility’s electricity metres. The communications network trunk consists of a fibre optic ring with individual connections via wired or wireless communication.
There is a thermal sludge drying unit at the Thessaloniki Wastewater Treatment Facility with its own independent automation system. Processes are controlled via local automation panels with PLCs and control screens. The control centre has a SCADA system of two redundant servers, in the form of client-servers, a CCTV system and a local server for the maintenance programme. Communication is via fibre optics and electrical wiring.
2) Aineia Wastewater Treatment Facility
At the Aineia facility, the local automation panels include control screens with similar characteristics as those at the Thessaloniki Wastewater Treatment Facility. Additionally, there are sewage pumping stations for tourist areas where the local automation panels controlling their operation do not have control screens but selector switches, buttons and indicators lights. These can operate the pumps through conventional automation in the event of a PLC malfunction. The control centre has a SCADA system of two redundant servers, in the form of client-servers, a CCTV system and a local server for the maintenance programme. The facility’s communication network consists of a fibre optic ring. The pumping stations have dual communication. The main one is wireless Ethernet, with ADSL at some, while back-up communication is GPRS-based, through mobile telephony.
3) Waste Treatment Unit (WTU)
The automation system at the WTU includes the local panels with PLCs, the control centre with the SCADA server and the large display screen, as well as a fibre optic ring communications network
Automation and Remote Control at the Wastewater Pumping Stations
EYATH is currently managing an extensive network of pumping stations where sewage is collected by gravity and then pumped to the central sewerage pipeline. Remote control is achieved through a modern control centre, while the sewerage pumping stations can also operate autonomously. The automation of pumping stations relies on the local control system at the pumping stations, the form of communication between pumping stations and the control centre, and the SCADA system at the control centre. An electrical metal panel is installed at each pumping station on which the electronic and electrical equipment is mounted and which is necessary to control the pumps, including a programmable logic controller, digital I/O cards, analogue input cards, power supply, current transducers, relay output, and a radio data modem. Each pumping station has a modem to transfer data to and from the control centre. Most of the communication is over transceivers with VHF and UHF, and through mobile telephony technology. The SCADA system at the control centre can display the current operating status of the pumping stations in a mimic diagram, warns of changes in the optimal status and allows for remote control of the pumping stations.
Automation and Remote Control Systems at the Water Supply Facilities
EYATH currently manages a large number of water supply facilities (41 water pumping stations, 45 storage tanks and 25 active wells) to supply Thessaloniki with water, both directly from the Aravissos springs and from the River Aliakmonas once it is treated at the Thessaloniki Water Treatment Plant. The facilities cover a large geographical area – from the Aravissos springs in Pella Prefecture and the Aliakmonas dam in Agia Varvara in Imathia Prefecture, and up to and including the Greater Thessaloniki Area.
Two control centres are in operation to perform the essential telemetry and remote control of the above facilities using various Supervisory Control and Data Acquisition (SCADA) systems, while the facilities can also operate autonomously through local automation.
As part of modernising the water supply pumping stations in recent years, an integrated telemetry-remote control system was designed and built. To date, the system includes 1) 31 local stations, placed at pumping stations and storage tanks, 2) 3 remote control stations and 3) 1 central control station. For security reasons, a controlled access and alarm system has also been designed and installed at all local stations and includes closed-circuit cameras.
The entire integrated telemetry system has been developed to work over an Ethernet network, over VPN-MPLS and a privately owned wireless network as an extension to it. A mobile telephony (3G router) connection serves as a back-up connection between local stations and the central control station, as well as between the local stations, where required. The central control station communicates with all local stations and the 3 remote control stations with the central station as a client-server. Additionally, the local stations communicate with each other when necessary for the operation of the facilities (e.g. a pumping station upstream with a storage tank downstream).
EYATH has embarked on a tender process to develop a new, state-of-the-art SCADA system that will include all of the water supply facilities. The project includes modernising all water supply facilities with new automation panels and new technology programmable logic controller (PLC) systems for both local automation and remote supervision and operation. A controlled access and alarm system has also been designed and will be installed at all local stations. The entire integrated telemetry system will be developed on an Ethernet network, over VPN-MPLS. A mobile telephony (3G router) connection will serve as a back-up connection between local stations and the central control station, as well as between local stations.