Section 11(1)(a) in The Merchant Shipping (Prevention of Pollution by Sewage from Ships) Rules, 2010
(a)the ship is discharging comminuted and disinfected sewage using such system as specified under clause (b) of rule 9 at a distance of more than three nautical miles from the nearest land, or sewage which is not comminuted or disinfected at a distance of more than twelve nautical miles from the nearest land ;