Sewage Treatment Units

Promac's Sewage Treatment Plant (STP series) for gravity and vacuum toilet systems are designed to the latest state of aerated, submerged treatment principle.

This high efficient system is approved to IMO Resolution MEPC 2 (VI) and Helsinki Convention.


It is type tested and certified in accordance with IMO Resolution MEPC 159(55) to meet the operational requirements referred to in Regulation 9.1.1. of Annex IV of the International Convention for the Prevention of Pollution from Ships, MARPOL  73/78 as modified by Resolution MEPC 115(51).




  • Vacuum system: 11 - 148 persons
  • Gravity system:    7 - 105 persons


Please contact us for more information.


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Van Voordenpark 14

P.O. Box 22
5300 AA Zaltbommel
The Netherlands


Phone: +31 (0)418 68 33 33