At what range from land must the oily water seperator overboard discharge valve be shut and locked off?

Question

I can't find anything in MARPOL about ranges that the valve must be padlocked. Is it IMO requirement or that of local MCO? Oh and this is for Merchant vessels greater than 10000gt

Answer 1

b. The Coast Guard has tested several units and issued approval certificates under 46 CFR 162.050. Numerous ZMCO member nations have tested and approved equipment in accordance with Resolution A.393(X). Revisions to the existing requirements in 33 CFR 155 currently being developed by the Coast Guard (G-W) will implement this upcoming Marpol requirement for the use of oil-water separators and alarms capable of <l5 ppm operation while a vessel is within 12 miles from nearest land. Beyond 12 miles, <l00 ppm discharges of bilge or fuel oil tank ballast water will be permitted. When these revisions are implemented, approval in accordance with 46 CER 162.050 will be required for U.S. flag inspected vessels and satisfactory testing to IMCO Resolution A.393(X) will be accepted for all other vessels. It is anticipated that oil-water separators installed prior to the issuance of these regulations will be grandfathered. However, the 15 ppm bilge alarm will not. All alarms must comply with the applicable approval testing standard.

Answer 2

Discharging of any oil is a fine anywhere>

Answer 3

2 mile