1. Discharges to the sea
Sewage
Name – Date

2. Discharges to the sea - Sewage
Contents
Sewage from ships
Impacts of sewage
The role of shipping 2
Photo credits: Weeks Bay NERRS website/ Green Award Foundation

3. Sewage from all ships: Black water: waste from toilets, and;
Grey water: water from sinks, showers, galleys (kitchens), laundry and cleaning activities.
Photo credits: ProSea

4. Additional waste streams:
Large quantities of waste water from cruise and passenger vessels
Waste from the livestock cargo, in most cases cows, sheep or goats
Photo credits:ProSea/Vroon

5. Open oceans and coastal seas are different!
Reason why sewage regulations are area dependent (distance to coast)
Photo credits: Rovert Simmon, NASA GSFC Eartg Observatory, based on data provided by Watson Gregg, NASA GSFC

6. Impacts: - Oxygen depletion - Nutrient enrichment
Impacts: - Oxygen depletion - Nutrient enrichment  can lead to ‘dead zones’
Photo credits: Weeks Bay NERRS website / NOAA

7. Biggest problems
Discharge in enclosed sea areas (Meditteranean, Baltic Sea)
Discharge in sea areas with:
High water temperatures
Low oxygen
Little currents 7
Photo credits: Hellenic Centre of Marine Research 7

8. Additional issues
Passenger, cruise vessels and livestock carriers produce large amounts of sewage
Sewage may contain diseases/pathogens from human waste or chemicals from cleaning agents 8
Photo credits: Wallenius Wilhelmsen Logistics 8

9. Discharge of sewage at sea
Regulations
Discharge of sewage at sea
Level of treatment
> 12 n. miles
3 – 12 n. miles
< 3 n. miles
Comminuted and disinfected sewage
Allowed
Prohibited
Treated sewage through an approved treatment plant
Sewage stored in holding tanks
Photo credits:Holland America Lines

10. Questions?