Section 20(2)(a) in The Chennai Metropolitan Water Supply and Sewerage Act, 1978
(a)For the purpose of sub-section (1), the number of employees to be transferred to the service of the Board shall not exceed the total number of employees of the existing authority serving as on the first day of January, 1977, in connection with the water-supply or sewerage system maintained by such existing authority for the [Chennai] [Substituted for the word 'Madras' by the City of Madras (Alteration of Name) Act, 1996 (Tamil Nadu Act 28 of 1996).] Metropolitan Area.