15 PPM Bilge Alarm Monitoring: Understanding the regulations, responsibility and procedures

We at Shivtech strongly believe that for every seafarer, owner, ship manager and service provider, it is non-negotiable to prioritize:

  • The safety & well-being of the People

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Our work ensures these 3Ps are delivered to maximize economic viability for our clients globally.

The last thing a ship’s staff, owner, manager and surveyor would want, is a pollution related accident or leak. As the shipping laws have evolved over the past few decades and pollution control measures have become more stringent, the importance of proper maintenance and service to 15PPM Bilge Alarm Monitors has increase significantly. For PSC inspectors and surveyors, oily water separator (OWS) has always been a preferred choice of machinery on the ship for inspection, which is why the maintenance, service and attendance by only authorized service centres is essential to ensure satisfactory performance.

Every vessel produces a mixture of oil and water during its normal course of operations. This mixture is processed through an Oily Water Separator (OWS) on the vessel (Bilge Separator) which separates the mixture to enable discharge of water overboard. It separates the maximum amount of oil particles from the oil-water mixture coming from the engine room/s or cargo hold bilges, oil tanks and oil-contaminated spaces. A 15PPM Bilge Alarm Monitor is fitted to the OWS or Bilge Water Separator, which constantly monitors the oil content of the filtered water coming out of the separator. The monitor stops overboard discharge when the filtered water has oil content greater than 15ppm (parts per million). The set limit of ppm can depend on the requirement of the vessel and the area of its operation.

Regulation for Oily Water Separator:

As per Annex 1 of MARPOL under regulation 4 specified under paragraphs 2, 3, and 6, any direct discharge of oil or oily water mixture into the sea shall be prohibited. The regulation further explains how an oily water mixture can be treated onboard and can be discharged out at sea:

Oil Water Discharge Regulation-

For a ship with 400 GT and above, discharge of oil mixture can be done under the following conditions:

  • The ship is en route;

  • The oily mixture is processed through an oil-water separator filter meeting the requirements of regulation 14 of this Annex;

  • After passing the oil-water separator system, the oil content of the effluent without dilution does not exceed 15 parts per million;

  • The oily mixture does not originate from cargo pump-room bilges on oil tankers

  • In oil tanker ship, the oil-water mixture is not mixed with oil cargo residues

When the ship is plying in the Antarctic area, any discharge into the sea of oil or oily mixtures from any vessel shall be prohibited. PROCEDURE

Ship Staff & Managers must ensure that only Authorized OEM service providers attend to the 15PPM Bilge Alarm Monitors in order to pass IOPP surveys, maintain the performance of the unit and also prevent any damage to this sensitive unit if operated by unauthorized staff.

  1. According the MEPC.107(49) § 4.2.11 the unit must be checked at IOPP Certificate renewal survey by the manufacturer or persons authorized by the manufacturer. Alternatively, the unit may be replaced by a calibrated 15 ppm Bilge Alarm/ Measuring Cell. The Calibration Certificate with the date of the last calibration check should be retained onboard for inspection purposes.

  2. If for some reasons the computer unit needs to be changed, it has to make sure, that the memory card will remain on board for at least 18 month. The new computer unit will carry its own memory card. The old card can be insert into the new unit only for reading.

Shivtech’s One-Stop Solution Portfolio

For any repairs, calibration, spares parts and new unit requirements, Shivtech is a market leader in genuine service and the best economic solutions to all requirements in 15PPM Bilge Alarm Monitors and ODMEs. Feel free to get in touch with us for any troubleshooting or problems you face, our experts will be happy to help you.


Bilgmon488 bilge Monitoring & 15 ppm Bilge Alarm. (n.d.). Retrieved from

Oily Water Separator: Construction and Working. (2021, August 27). Retrieved from