Section 16. If, when the department approves an issue of new stock, bonds or other securities by a gas or electric company, it determines that the fair structural value of the plant and of the land and the fair value of the nuclear fuel, gas inventories or fossil fuel inventories owned by such company is less than its outstanding stock and debt, it may prescribe such conditions and requirements as it deems best adapted to make good within a reasonable time the impairment of the capital stock; or before allowing an increase, it may require the capital stock to be reduced by a prescribed amount, not exceeding the amount of such impairment. The amount of impairment and the conditions and requirements imposed shall be stated in the annual report of the department. The supreme judicial or superior court shall have jurisdiction in equity, on application of the department, the attorney general, any stockholder or any interested party, to enforce this section and section fourteen and all orders and decisions, conditions or requirements of the department made in pursuance thereof.