The main legal point established in the judgment is the interpretation of the provisions of the Water Act, Cess Act, and Environment Act, particularly regarding the eligibility for rebate under the Cess Act and the unit of measurement for rebate calculation.

Arijit Pasayat, C.J.

These eight appeals are directed against the common judgment dated 20.11.1998 passed by learned single judge disposing of four Original Petitions viz. O.P. Nos. 8592 of 1990, 445, 1120 and 1970 of 1995. Four Writ Appeals have been filed by the Kerala State Pollution Control Board, Thiruvananthapuram, (in short 'the board) and four appeals have been filed by the Travancore Rayons Ltd., Rayonpuram (in short, 'the Company').

2. Background facts are undisputed and need to be noted in brief. Company is a public limited one, manufacturing rayon and cellophane. For various purposes of the factory, water is drawn from Periyar river and is used for manufacturing, domestic purposes, generating streams etc. In course of manufacture, some quantity of water get polluted, which is treated in the Effluent Treatment Plant of the factory and treated water is discharged back to river again. For such discharge, consent from Board is necessary in terms of Water (Prevention and Control of Pollution) Act, 1974 (in short 'the Water act). Said consent is valid for three years. Condition No. 4 of the consent order indicates the tolerance limits, that is the effluent characteristic, should be within the indicated tolerance limit.

3. Water (Prevention and Control of Pollution) Cess Act, 1977 (in short 'the Cess act) provides for levy of cess on the water consumed by every local authority or specified industry. According to S.7 of the said Act, rebate cess payable would be granted if person liable to pay cess instals any plant for treatment of sewage of trade effluent. R.6 of the Water (Prevention and Control of Pollution) Cess Rules, 1978 (in short, 'the rules') allows rebate where a consumer instals any plant for treatment of sewage or trade effluent and such rebate is available from expiry of 15 days from the date on which such plant is successfully commissioned, and so long as plant functions successfully. R.4 of Cess Rules requires filing of return by fifth of every calendar month in Form No. 1. The rate of rebate is different at different points of time and we shall deal with the rates a little later.

4. Company's stand was that it has installed effluent treatment plant much before Pollution Control Act or Cess Act came in to force. Plant installed in the factory is a very efficient one and is functioning regularly and effluent is discharged only after proper treatment in said plant. Company has to test the treated effluent and furnish test results to the Board along with monthly return submitted by it under R.4 of Cess Rules. Consent order granted to company mentioned nine parametres of pollutants i.e., tolerant limit and company has always been achieving 100% result with regard to seven items. There has been occasional variations in PH (acidity and alkalinity) and on very rare occasions, variation of Biological Oxygen Demand (in short 'BOD'). For last several years, according to company, there has been variation in PH or BOD on an average of five days in a month. Because of this variation, rebate to which company is entitled to, is not granted by the Board. According to it, barring those days when there were variations i.e., days when tolerance limit was exceeded, which can, admittedly, be ascertained, company ought to have been granted rebate in respect of those days when discharged water treated in effluent treatment plant and put back in the river was well within tolerance limit. In other words, it is stated, department was taking calendar month as a unit and rejecting rebate for the whole month, even if there has been occasional variations for a few days in a month. Same is contrary to provisions of the Act. Dispute relates to two periods i.e., (a) from May 1981 to November 1984 and (b) November, 1986 to December, 1994. Appeals were filed before Appellate Committee for Water Cess (in short, Appellate Committee), which rejected the appeals on the ground that even if company failed to satisfy conditions of the conse