Foreword
The Minimal National Standards (MINAS) for a particular industry are the effluent standards achievable by the industry by installing pollution control measures which are within the techno-economic capability of the industry. Depending on the seriousness of the pollution and techno-economic assessment of the requisite pollution control measure, the MINAS may be attained in one stroke or in phases. The evolution of MINAS thus remain independent of the characteristics of the recipient environment. The Central and State Boards for Pollution Control have come to an agreement that under no circumstances MINAS would be relaxed as because the same is techno-economically acceptable to the industry. On the contrary, at situations where the recipient environment demands stricter quality of the effluent of the industry the State Boards are required to prescribe standards stricter than MINAS.
The present treatise, belongs to the series-Comprehensive Industry Document Series: COINDs, contains the salient highlights pertainir,g to mercury cell units discussed in the main document prepared ~n respect ofCausticsoda Industry, andthe MINAs developed for the

mercurycell units of the Industry. In depth discussions were held with the Alkali Manufacturers' Association of India to arrive at the MINAs. The cooperation extended by the Association is gratefully acknowledged. The main document on the Caustic Soda Industry was prepared by Dr. sivabrata Chatterjee, Consultant, Cafcutta.
Dr. K.R. Ranganathan, Environmental Engineer, Central Board co-ordinated the activities in preparing the main document and prepared the present report on MINAS for mercury cell units.
The document should be usefu1 to the industry, the regulatory agencies, the consultants and to all interested in pollution control.