AWWA ACE58281

City of Laval was the first in Qu¿bec, Canada, to follow the International Water Treatment Alliance's (IWTA) methods to seek for water quality improvements. In 1998, the first step was to present the program, its methods, its objectives and its success story in the United States to managers and professionals. The great interest it attracted came from the fact that all aspects of water treatment are involved: administration, design, procedures, equipment, training, maintenance, operation, etc. After they were introduced to the program, maintenance and operation personnel joined in and participated in each step. This paper presents the improvements that resulted from the implementation of the IWTA methods in the three water treatment plants: Chomedey, Pont-Viau and St. Rose. With a lot of good will and no major investment, the low performance periods have almost all been eliminated. The City of Laval experience demonstrates the advantages of joining the program. The program allowed great improvement of the removal of disinfection resistant microorganisms. The 95th percentile for combined filtered water has gone from 0.22 to 0.08 NTU for Chomedey plant, from 0.14 to 0.07 NTU for Pont-Viau plant and from 0.16 to 0.07 for St. Rose plant. Furthermore, the percent of turbidity below 0.10 NTU went from 63% to 99% for Chomedey, from 88% ro 99% for Pont-Viau and from 82% to 99.9% NTU for St. Rose. Includes abstract only.