CAURALI: sewerage at the Lille Métropole Communauté Urbaine (LMCU) under control

Before, the LMCU had a remote management system running under Unix, installed in 1994 (241 pumping stations) and a TOPKAPI system installed in 1999 (22 waste water treatment plants), which at the time was the first full hot redundant remote management system in France.
 

Modernize the supervision system for all works
 

Within the framework of environment preservation and flood prevention, the LMCU wished to implement tools improving availability of sewerage systems and anticipating impacting events.

Late 2004, a call for tender was launched for a global supervision system covering all structures: 288 pumping stations, 29 treatment plants, 11 storage tanks, 5 valves, 27 flow measuring stations and 20 rain gauges, i.e. close to a total 400 structures. Early 2005, the project, named CAURALI ('Contrôle Automatisé du Réseau d'Assainissement Lillois', Automated control of the Lille sewerage network), was entrusted with Automatismes Seguin.

For the Metrology Unit, in charge of the project within the Water and Sewerage Department of the Lille Urban Community, the overall design had to meet the requirements of information continuity and ease of operation.
 
The heart of the system is made of two couples of redundant servers; each server station processes a part of the application (distributed processing) and provides the associated server backups should the main servers fail. Two other redundant servers ensure autonomously data processing for a treatment plant.
All these servers feed raw data into a central database under Oracle: every day, the system generates the storage of about 4 million basic records, i.e. 70GB data per year. To manage such a volume of information in good conditions, a quarterly partitioning of the base was implemented. Please note that unicity of the data sent to this base is ensured by Topkapi redundancy, which handles the processes related with failure events.

The raw data is then reprocessed within the database by a consolidation application developed specifically, which consolidates calculations and generates reports.
 
Communication with local controllers is performed mainly through the switched telephone network (Remote Terminal Units - RTUs: Napac, Perax, Sofrel). For the most sensitive sites, about thirty of them, a permanent real-time link with the central site was required; ADSL support is more economical than a leased line, but, except paying a very high price, it does not guarantee continuity of service.

This obstacle is worked around by Topkapi, which provides a backup for the ADSL link by a connection over the switched telephone network, without having to adapt the settings of basic variables.
 
To operate the system, the user has:

• an operating station in the control room with a Barco overhead projector
• a fixed client station at the waste water treatment department, also acting as web server and archive processing station
• two remote-connectable mobile operating stations
• overall access, using a web browser from any computer in the Intranet, to supervision screens (viewing and controls according to access rights) and database consolidated reports
• standby management functions

A minor technical particularity which will probably be of interest for some of our readers, LMCU wanted to have a function of the memo type, to enter operating notes for each of the sites. This function was provided by the system integrator, who developed a small application: when the operator clicks a 'Post it' object in synoptics, a html window opens a form to display and edit a memo stored in an external database (accessible to all client stations). The presence of a memo is then reported to the users by means of an indicator (using the TVision Active-X for data exchange between the two applications).

The use of a VPN network between the system integrator’s premises near Paris and those of LMCU contributed to reducing costs of this major project, while allowing a large part of remote development and deployment.