MARPOL Annex IV

MARPOL ANNEX IV
Regulations for prevention of pollution by sewage in ships

✽ Regulation 1: Definition Sewage;

• Drainage & other wastes from;

             ✧ Toilets & urinals

             ✧ Hospital

             ✧ Spaces with living animals

• Other waste water mixed with above.

✽ Regulation 2: Application

• Ships above 400 GT &/or ships carrying more than 15 persons engaged in international voyages.

✽ Regulation 3: Exceptions

• For safety of ship and those on board or to save life at sea.
• Due to damage to ship or equipment (all reasonable precautions taken).

✽ Regulation 4: Surveys

• Initial (issue certificate), Renewal (not exceeding 5 yrs.).
• Certificate issued by Administration or by a Recognized Organization authorized by it.
• Certificate: International Sewage Pollution Prevention Certificate (Valid: 5 yrs.).

✽ Regulation 9: Sewage systems

• Every ship (according to reg. 2) shall be equipped with one of the following;

            ✧ A STP approved by Administration (MEPC effluent standards).
            ✧ Sewage comminuting & disinfecting system approved by the Administration.
            ✧ A holding tank of capacity satisfying the Administration.

✽ Regulation 10: Standard discharge connection

• OD: 210mm 
• PCD: 170mm 
• Thickness 16mm
• 4 holes 18mm diam. Slotted Slot: 18mm
• Steel
• Bolt: M16

✽ Regulation 11: Discharge

• Ships, other than passenger ships in all areas; and
• Passenger ships outside special areas;

From STP	Comminuted & Disinfected	Untreated
✓ Certified STP meeting requirements. ✓ No visible floating solids & no discoloration of surrounding water	✓ At least 3 nm away from nearest land.	✓ At least 12 nm away from    nearest land. ✓ Approved disch. Rate. ✓ Proceeding en route. ✓ Minimum speed 4 kts.

• When sewage is mixed with matter covered by other Annexes, the requirements of those annexes will be applied in addition to requirements of this annex.

✽ Within a Special Area (Baltic Sea)

• Discharge of Sewage Prohibited for passenger ships except when;

           ✓ Ship has a STP certified by Administration meeting the Effluent Standards + remove Nitrogen & Phosphorous (total N: 20 mg/l, P: 1 mg/l)

✽ STP Effluent Standards (MEPC.227(64))

    Testing methods: according to MEPC.227(64) Guidelines

Thermotolerant Coliform	100/100 ml
Total Suspended Solids	35 mg/l
BOD5	25 mg/l
COD	125 mg/l
pH	6 – 8.5

✽ Untreated sewage discharge rate

• 1/200 000 of swept volume

• Disch. Rate _Max  = 0.00926   V    D    B

           Disch. Rate Max - (m3/h) Average rate for a period of 24 hours
           0.00926 - Kts. → m/h
                              200 000
           V - Speed (kts)
           D - Draft (m)
           B - Ship’s Breadth (m)

• Calculated up to max Summer draft & max Speed and a table is prepared.
• Then the pump is calibrated to a moderate rate.

Example