The certification for sewage treatment plants under the regulations of IMO (International Maritime Organisation) and the EU (European Union) continues to be a source of confusion, misunderstanding and misinformation within the maritime industry. Certificates issued under the EU Marine Equipment Directive (MED) are time and again confused with IMO certificates. In addition, EU MED certificates are sometimes thought to be equivalent to an IMO certificate, which they are not. In this guide, we try to give an overview of the facts and to clear some misconceptions.
- EC Type Examination (Module B, MED-B) certificates and IMO certificates are two different things. The note on MED-B (Modul B) certificates that a plant complies with IMO regulation only states that the manufacturer could convince the certifying body of the compliance. It does not state, that the plant has been tested by the certifying body to IMO standards.
- EC Type Examination (Module B, MED-B) certificates do not replace IMO certificates
- Within the EU, both MED-B and IMO certificates are needed, outside of the EU, only IMO certificates are needed
- The weakness of the EC Type Examination (Module B, MED-B) certification process seems to be the lack of verification of information handed in by the applying manufacturer
OBJECTIVE OF IMO REGULATION
Ensuring that sewage is effectively treated by setting values for effluent quality and testing them in operation.
IMO CERTIFICATION PROCEDURE
IMO certificates are valid worldwide. They confirm that the STP complies with the required effluent values.
To receive IMO certification, a 10-day test in operation has to be successfully completed, during which the influent and effluent quality is constantly monitored. In addition, the electrical test to MEPC.107(49) (vibration, temperature and humidity) has to be cleared.
An IMO certificate carries the following headline (may vary slightly):
“CERTIFICATE OF TYPE APPROVAL FOR SEWAGE TREATMENT PLANTS Issued under the authority of the government of [member state]”
The underlying regulation are currently IMO Resolutions MEPC.227(64) excl. or incl. Section 4.2 (MARPOL Annex IV special areas) and MEPC.107(49).
Every IMO member state has one authorized certifying body that can issue IMO certificates, in Germany the BG Verkehr, in Norway is a state authority directly. The manufacturer has to use the certifying body in the state where he has his registered head office.
INFORMATION ON IMO CERTIFICATION STATUS
The status of IMO certificates for a specific product is listed at https://gisis.imo.org
OBJECTIVE OF EU REGULATION
Harmonization of the implementation of standards set by international bodies like IMO among EU member states to ensure the smooth functioning of the EU internal market.
EU CONFORMITY ASSESMENT PROCEDURE
EC Type Examination Certificates (Module B) only confirm that a product may be placed on the EU internal market. They are of no value outside of the EU.
To receive a MED Module B certificate, has to document that the STP complies with IMO regulation, but no separate test in operation is carried out to validate the information given by the manufacturer.
A MED Module B certificate carries the following headline and carries the wheelmark sign:
“EC TYPE EXAMINATION CERTIFICATE (Module B)”
The underlying regulation is currently Marine Equipment Directive (MED) 2014/90/EU, as amended by Commission Implementing Regulation (EU) 2018/773.
Every EU member state has authorized one or more notified bodies that can issue MED certificates, in Germany that is among others BG Verkehr and DNVGL. The manufacturer can use a certifying body of his choice that is authorized by the state where he has his registered head office.
The key certificate is MED Module B (MED-B, Type approval). It needs to be complemented with either one of the modules D, E, F – an MED-B alone is not enough to place a product on the market. 
INFORMATION ON EU MED CERTIFICATION STATUS
The status of MED certificates for a specific product is listed at www.mared.org
NOTES ON CERTIFICATES FOR PLANTS RELYING ON THE DILUTION PRINCIPLE
MED-B EC Type Examination certificates that are based on test reports dated prior to October 2012 should to be treated with caution. These tests were carried out under the standards of the then valid IMO resolution MEPC.159(55), which did not take dilution of sewage with seawater into consideration.NOTES ON CERTIFICATES FOR PLANTS RELYING ON THE DILUTION PRINCIPLE
When MEPC.227(64) was adopted in October 2012, seawater dilution of sewage was ruled out by introducing the dilution factor. Unless the manufacturer could credibly prove that seawater dilution was not used during MEPC.159(55) certification (like HAMANN did), a new test in operation would have been mandatory.
However, some plants on the market are obviously still based on the dilution principle, as the product specifications published by the manufacturers continue to show a seawater intake directly into the treatment tank.
 As there is always a combination of MED-B and MED-D/E/F or G certificates necessary to place a product on the market, certification has to be considered invalid as soon as one (e.g. MED-D) certificate of the combination is invalid. EC Type Examination (MED-B) certificates of DNVGL state it clearly as well: “The manufacturer is allowed to affix the Mark of Conformity according to Article 11 in the Council Directive 96/98/EC on Marine Equipment and shall issue a Declaration of Conformity, only when the module D or E or F of Annex B in the same directive is fully complied with.”