Advances in Water Treatment and Enviromental Management

ADDRESSThe theme of the conference—progress in the field of managing the environment—is particularly interesting to thepeople of Lyon. Courly may justifiably lay claim to the privilege of being an economic metropolis within a remarkableenvironment.Two subjects exemplify (especially the supply of drinking water) the Lyonese sensitivity to environmental problems.1 SUPPLY OF DRINKING WATERThe initial security is assured through a perennial resource, both quantitatively and qualitatively. Quantitatively, thedrinking water supply of the urban community of Lyons is for the most part guaranteed by the great alluvial watertable of the Rhône; production may further mobilise resupply reservoirs. Although equipped since 1976 with statutoryprotection perimeters (400 hectares of which are in the immediate area), this catchment zone remains a tributary ofthe river. The situation requires very special viligance over the entire upper waters of the Rhône to ensure that therisk of accidental pollution (industry and roads) does not jeopardise the functioning of this resource.Then, the new risks linked to economic and industrial development must be overcome. How do these affect Lyon?First, there is the permanent requirement for an ever greater security. The increasing complexity of our city makes itall the more vulnerable. We know the risks involved for a large conurbation of a long-term break in the water supply.Searching for an answer to this problem gave rise to a universal re-think concerning the security of the supply, to anoriginal initiative and finally to an emergency water treatment plant. This plant is solely intended to operate in theevent of accidental pollution of the Rhône, constituting complete alerting mechanism (comprising a list of risks, ofequipment for the real time detection of pollution, etc.).Today, this concern to improve security is taking priority over policies designed to increase the capacity of theinstallations: 90% of our investment is investment in security and redundancy.2 On the other hand, solving technical problems relating to the environment has always been accompanied by the willto develop technologies taken on in a close partnership with companies which are working with Courly.3 Similarly, in the area of sanitation, which, contrary to that of drinking water, has not progressed in the course ofrecent decades, Courly has developed new technologies and new operating equipment. This includes:• the construction of two fixed culture purification plants: one at Meyzieu with a capacity of 35 000 Eq/inhab. andone at Fontaines-Sur-Saone with a capacity of 40 000 Eq/inhab. approximately. Apart from their advancedtechnology and their fundamental water treatment role, these two plants have been designed with two essentialobjectives: protecting the environment (odours, noise, appearance) and major facilities made available to theoperator enabling him to control and regulate the functioning of the plant and its purification performances.• the development of an expert system to assist decision-making at the Meyzieu purification plant (ORAGE). Thisequipment offers the plant operator guidance when making his major decisions (flow-rate to be treated, numberof works in operation, preventive maintenance, sludge treatment), no longer according to currently availableresources and common practice, but on the basis of rational data and real measurements edited and stored bythe system.• setting up the GESICA system (Management, Simulation and design of Sanitation). This system, based on thecomputerised urban cartography on which the sanitation network is located, enables the design office and thenetwork operator to obtain assistance in the planning of investment (network calibration, hydraulic load) andrehabilitations (condition of structures), to rationalise the sewage purification campaigns and to act rapidly in theevent of accidental pollution.• installing equipment for the remote management of networks and purification and detection plants (TERESTA).This equipment centralises, in real time, the data from 60 plants (purification and detection), thereby making itpossible to take very rapid action with respect to operating faults, to carry out preventive maintenance on theinstallations, to manage operating costs and to bring operating personnel a great deal of comfort and flexibility intheir work.These innovations are put into practice in a permanent spirit of partnership between the municipality of Courly, privateenterprise, the university and the ‘grandes écoles’, who are pooling their know-how, their experience and their respectiveresources.These efforts clearly contribute to the accomplishment of the tasks of the Sanitation Services, which are the collection,transportation and treatment of waste water. In addition, the Sanitation Service is increasingly sensitive to the necessityof dealing with rainwater and the pollution that it entrains.C MansatSanitation ServiceLyon. June 1990vii