Sewage Plant

Question 1

Annex 4 MARPOL, STP functions and maintenance?

Answer 1

Annex 4 - Prevention of Pollution by Sewage from Ships.

A vessel above 400GT or less but carries more than 15 passangers

Vessel has a typed approved STP it will have a sewage certificate that contains test results that it has no visible solids or discolouration when discharging.

Treated can be 3nm, untreated is 12nm. Both while underway en route at least 4 knots.

Question 2

Testing of effluent and limits?

Answer 2

Test every month by taking sample, Check the colour, smell and for any visible objects.

3 monthly send off to a lab to correspond with the chlorine levels on the sewage certificate. Should match the certificates results

Question 3

What system do you have onboard?

Answer 3

We are running an aerobatic system made by DVZ

Question 4

Dangers of operating in an anaerobic state?

Answer 4

It can start producing harmful gases such as hydrogen sulfide (H2S), methane (CH4), and carbon dioxide (CO2)

Anaerobic environments can increase the rate anaerobic bacteria

Increase risk of fire from methane

Increased corrosion rate