Approval under section 10(23G) grants tax-favoured status to a sewage treatment plant operator, subject to audit and compliance. Approval under section 10(23G) read with rule 2E grants tax-favoured status to M/s First STP Pvt. Ltd. for construction, operation and maintenance of a sewage treatment plant for Alandur Municipality, effective for the lease period specified in the underlying agreements; the approval is conditional on compliance with section 10(23G) and rule 2E and on maintaining audited books and furnishing the audit report, and may be withdrawn if the eligible business ceases or audit and reporting requirements are not met.