Sewage Treatment Plant
high
IMO Required
Biological/chemical sewage treatment as per MARPOL Annex IV. (See also Engine Room.)
5 yr
Class Survey
15 yr
Typical Lifetime
Typical Manufacturers
Wärtsilä (Hamworthy)
Alfa Laval
ACO Marine
Known Models (3)
JETS Vacuum (Norway) Vacumarator Sewage System
10-300 Persons
· Black Water (Vacuum System)
Voltage: 380-440V
type: Vacuum Toilet + Sewage Treatment System
size_range: ['JETS 10', 'JETS 50', 'JETS 100', 'JETS 300']
variant_count_approx: 4
period_start_year: 1985
period_end_year: None
drive_type: Electric (vacuum pump)
construction: Vacuum toilets, collection tank, vacuum pump, treatment unit
Common Failures:
- • Vacuum pump failure (diaphragm wear)
- • Vacuum valve leakage causing loss of vacuum
- • Discharge pump blockage
- • Treatment unit biological process upset
- • Sensor/control failure
Service: Vacuum pump maintenance quarterly. Vacuum valve test monthly. Treatment unit biological parameters monitoring weekly. Discharge sampling per MARPOL.
Spares: JETS Vacuum (Hareid, Norway). Lead time: 2-4 weeks.
RWO / Veolia (Germany/France) Biological Sewage Treatment Plant
10-100 Persons
· Black Water Treatment
Voltage: 380-440V
type: Biological Sewage Treatment Plant (Extended Aeration)
size_range: ['STP-10', 'STP-25', 'STP-50', 'STP-100']
variant_count_approx: 4
period_start_year: 1985
period_end_year: None
drive_type: Electric
construction: Biological reactor, aeration system, settling tank, chlorination/UV
Common Failures:
- • Biological process upset from chemical contamination
- • Aeration system blockage
- • Chlorinator malfunction
- • Sludge buildup from infrequent desludging
- • Effluent quality deterioration during low-occupancy periods
Service: Biological parameters monitoring weekly (DO, pH, TSS). Desludging when sludge level >50%. Chlorinator chemical supply check monthly. Effluent sampling per MARPOL.
Spares: RWO/Veolia (Bremen). Lead time: 2-4 weeks.
Wärtsilä / Hamworthy (Finland/UK) Membrane BioReactor (MBR) Sewage System
10-200 Persons
· Black/Grey Water Treatment
Voltage: 380-440V 3ph
type: Membrane BioReactor (MBR) Sewage Treatment Plant
size_range: ['MBR-10', 'MBR-50', 'MBR-100', 'MBR-200']
variant_count_approx: 4
period_start_year: 2005
period_end_year: None
drive_type: Electric
construction: Bioreactor tank, membrane filtration, UV disinfection, PLC control
Common Failures:
- • Membrane fouling requiring chemical cleaning
- • Aeration blower failure
- • UV lamp end-of-life
- • PLC control board failure
- • Sludge pump blockage from foreign objects
Service: Membrane cleaning (CIP) quarterly. UV lamp replacement annually. Aeration blower maintenance quarterly. Effluent quality sampling as per MARPOL Annex IV / IMO MEPC.227(64).
Spares: Wärtsilä/Hamworthy. Lead time: 3-6 weeks. Membrane modules: 4-8 weeks. UV lamps: 2-3 weeks.