(1) A tariff scheme for the services of a service licensee shall be based on the following general principles—
(a) tariffs must recover—
(i) the efficiently incurred costs of the service, and
(ii) a reasonable return on capital,
thereby permitting the service licensee to attain the objective of economic equilibrium;
(b) a tariff scheme must be explicit and elaborated in a manner so as to be easily understood, and must be made available to customers;
(c) subject to paragraph (d) a tariff must not be unduly discriminating, in the sense that all customers in the same category will be treated equally;
(d) when demand so permits, different tariffs may be established for differing localities, seasons, categories of customers, volumes of water provided and volumes of sewage discharged, if costs of the services so justify;
(e) subject to paragraph (d), a tariff scheme must not penalize the service licensee for—
(i) past benefits or benefits obtained from operating the services,
(ii) efficiency increases different from those considered in the tariff reviews; and
(f) a tariff scheme may permit the granting of a direct subsidy in accordance with section 83 or a cross subsidy in accordance with section 84.
(2) The Commission shall by order published in the Gazette and at least 2 newspapers in general weekly circulation in Saint Lucia—
(a) establish a tariff scheme for the services of a service licence;
(b) modify an existing tariff scheme in accordance with the modifications approved by the Commission for the services of a service licensee in accordance with section 80, 81 or 82.