RESOLUTION MEPC.227(64)
Adopted on 5 October
2012
2012 GUIDELINES ON IMPLEMENTATION OF EFFLUENT STANDARDS AND PERFORMANCE TESTS
FOR SEWAGE TREATMENT PLANTS
THE
MARINE ENVIRONMENT PROTECTION COMMITTEE,
RECALLING Article 38(a) of the Convention on the International Maritime Organization concerning
the functions of the Marine Environment Protection Committee (the Committee) conferred upon it by international conventions for the prevention and control of marine pollution,
NOTING resolution MEPC.159(55) by
which the Committee adopted, at its fifty-fifth session, the Revised Guidelines on implementation of effluent standards
and performance tests for sewage treatment plants (the Revised
Guidelines) and invited
Governments to apply the Revised Guidelines when approving sewage treatment plants and provide
the Organization with information on experience gained
with their application, in particular, on successful testing of
equipment against the standards contained in
the Revised Guidelines,
NOTING ALSO resolution MEPC.200(62) by which
the Committee adopted,
at its sixty-second session, amendments to MARPOL Annex IV concerning
Special Area provisions and the designation of the Baltic Sea as a special
area, which are expected to enter
into force on 1 January 2013,
NOTING FURTHER the provisions of regulations 9.1.1 and 9.2.1 of MARPOL Annex
IV, in which reference is made to the above-mentioned Revised Guidelines,
RECOGNIZING that the Revised Guidelines
should be amended in order that current trends
for the protection of the marine environment, the need to address
particular oceanographical and ecological conditions of the special area designated, and developments in the design and effectiveness of commercially available
sewage treatment plants be reflected; and the proliferation of differing unilateral more
stringent standards that might be imposed worldwide be avoided,
HAVING CONSIDERED the recommendation made by the Sub-Committee on Ship Design and Equipment, at its fifty-sixth session,
1. ADOPTS the 2012 Guidelines on implementation of effluent standards
and performance tests for sewage treatment plants, the text of which is set out in the annex to this resolution;
2. INVITES
governments to:
.1 implement the
2012 Guidelines and apply them on or after 1 January 2016; and
.2 provide the Organization with information on experience gained with the application of the 2012 Guidelines;
3. ALSO INVITES
Governments to issue an appropriate "Certificate of type approval
for sewage treatment plants" as referred to in paragraph
5.4.2 and the annex of the
2012 Guidelines and to recognize
certificates issued under the authority
of other Governments as having the same validity as certificates issued by them;
4. SUPERSEDES the Revised Guidelines
on implementation of effluent
standards and performance tests for sewage treatment plants, adopted by resolution MEPC.159(55).
ANNEX
2012 GUIDELINES ON IMPLEMENTATION OF EFFLUENT STANDARDS AND PERFORMANCE TESTS FOR SEWAGE TREATMENT PLANTS
TABLE OF CONTENTS
1 Introduction
2 Definitions
3 General
4 Technical specification
5 Testing considerations
6 Renewal and additional surveys
7 Familiarization of ship personnel in
the use of the sewage treatment plant
8 Maintenance
ANNEX
Form of Certificate of Type Approval for Sewage Treatment
Plants and appendix
2012 GUIDELINES ON IMPLEMENTATION OF EFFLUENT STANDARDS AND PERFORMANCE TESTS
FOR SEWAGE TREATMENT PLANTS
1 INTRODUCTION
1.1 Background
1.1.1 The Marine Environment Protection
Committee
(MEPC)
adopted resolution
MEPC.2(VI), Recommendation on International Effluent
Standards and Guidelines for Performance Tests for Sewage Treatment Plants in 1976.
MEPC 55 in October
2006 adopted, by resolution MEPC.159(55), the Revised Guidelines on implementation of effluent standards
and performance tests for
sewage
treatment
plants,
which
superseded resolution
MEPC.2(VI).
1.1.2 MEPC
62 adopted resolution MEPC.200(62) amending
MARPOL by designating the Baltic Sea as a special area under Annex IV and prohibiting the discharge of sewage effluent from passenger
ships operating in special areas, unless a passenger ship has in operation an approved sewage treatment plant implementing effluent
standards and performance
tests defined in the 2012
Guidelines on implementation of effluent standards
and performance tests
for sewage treatment plants (the Guidelines).
1.2 Application
1.2.1 These
Guidelines amend the Revised guidelines on implementation of effluent standards and performance tests for sewage
treatment plants, adopted by resolution
MEPC.159(55),
by including the standards of section 4.2 that only apply to passenger
ships which operate
in MARPOL Annex IV special
areas and which intend to discharge
treated sewage effluent into the sea.
1.2.2 The
requirements of these Guidelines, with the exception
of the requirements in section 4.2, will apply to sewage treatment
plants installed on or after 1 January 2016 on:
.1 ships, other than
passenger ships, in all areas; and
.2 passenger ships
outside MARPOL Annex IV
special areas.
1.2.3 The
requirements of these Guidelines, including
those in section
4.2, will apply to sewage treatment plants
installed on:
.1 new
passenger ships when operating in a MARPOL Annex IV special area and intending to discharge treated
sewage effluent into the sea on or after
1 January 2016; and
.2 existing passenger
ships when operating
in a MARPOL Annex IV special area and intending to discharge treated
sewage effluent into the sea on or after
1 January 2018.
1.2.4 Sewage treatment plants
installed
prior
to
1
January 2016 and on or after 1 January
2010, on ships other than passenger ships operating in MARPOL Annex IV special areas and intending to discharge
treated sewage effluent into the sea, should comply with resolution MEPC.159(55).
1.2.5 Sewage treatment plants installed prior
to 1 January 2010 on ships other
than passenger ships operating in MARPOL Annex IV special
areas and intending
to discharge treated sewage
effluent into the sea, should
comply with resolution MEPC.2(VI).
1.3 Purpose
1.3.1 These
Guidelines and specifications address the design,
installation, performance and testing of sewage treatment
plants required by regulations 9.1.1 and 9.2.1 of MARPOL Annex IV.
1.3.2 The
purpose of these Guidelines and specifications
is:
.1 to provide
a uniform interpretation of the requirements of regulations 9.1.1 and
9.2.1 of MARPOL Annex IV;
.2 to assist
Administrations in determining appropriate design, construction and operational testing and performance parameters for sewage
treatment plants when such equipment
is fitted in ships flying the flag of their State; and
.3 to provide
guidance for installation requirements.
2 DEFINITIONS
2.1 Annex IV – the revised Annex IV of the International Convention for the
Prevention of Pollution from Ships, 1973, as modified by the 1978 and 1997 Protocols (MARPOL),
as amended by resolutions MEPC.115(51) and MEPC.200(62).
2.2 Convention – the International Convention for the Prevention of Pollution from Ships,
1973, as modified by the 1978 and 1997 Protocols (MARPOL).
2.3 Dilution (Qd) – is dilution
water, grey water, process water, and/or seawater introduced
to the sewage treatment plant after the influent sample point and after the
influent flow measurement device, see figure
1.
2.4 Effluent (Qe) – treated
wastewater produced by the sewage treatment plant, see figure 1.
2.5 Flush
water – transport medium used to carry sewage or other wastes from toilets or
urinals to the treatment system.
2.6 Geometric
mean – the nth
root of the product of n numbers.
2.7 Grey
water – is drainage
from dishwater, galley sink, shower,
laundry, bath and washbasin drains and does not include
drainage from toilets,
urinals, hospitals, and animal spaces, as defined
in regulation 1.3 of MARPOL Annex IV and does not include
drainage from cargo
spaces.
2.8 Hydraulic loading – system design flow rate of waste water (Qi) into the sewage treatment plant.
2.9 Influent (Qi) – Liquid containing sewage,
grey water or other liquid streams, to be processed by the treatment plant, see figure
1.
2.10 Sample point – A point for manual collection of a representative sample of influent and
effluent without opening tanks, voids or vents, see figure 1.
2.11 Testing on board – testing,
for the purpose
of type approval, carried out on a sewage treatment plant installed on a ship.
2.12 Testing ashore – testing ashore,
for the purpose of type approval, carried
out on a sewage treatment plant.
2.13 Thermotolerant coliforms – the group of coliform
bacteria which produce
gas from lactose in
48 hours at 44.5°C. These organisms
are sometimes referred
to as "faecal coliforms"; however,
the term "thermotolerant coliforms" is now accepted
as more appropriate, since not all of these organisms are of faecal origin.
Figure 1:
System diagram of a sewage treatment plant
3 GENERAL
3.1 An approved
sewage treatment plant should meet the technical
specifications in section 4 and the tests outlined in these Guidelines. However, section 4.2 on nitrogen
and phosphorous removal applies
to passenger ships operating within a special area intending to discharge treated sewage effluent into the
sea. It should also be noted that, when ships are operating approved sewage
treatment plants, MARPOL
Annex IV also provides that the effluent shall not produce visible
floating solids or cause discolouration of the surrounding water.
3.2 In meeting the effluent standards in
section 4, an approved sewage treatment plant should not rely solely on dilution
of wastewater. Where amounts
of dilution are deemed essential
to a treatment process, the effluent standards
in section 4 having concentration limits (mg/l) should be adjusted
proportionally using dilution
compensation factor Qi/Qe to take account of dilution
Qd. In addition, for effluent standards in section 4 having a percentage reduction, the geometric mean of the daily percentage reduction values should be calculated using the accumulated flow Qi and
Qe over
each 24-hour test day, in terms of l/day,
multiplied by the geometric mean of the corresponding concentration Ci and Ce for the
same 24-hour test day, in terms of mg/l.
The overall percentage reduction over the entire test
period n is:
where PRn is the daily
removal value:
where:
n represents the test
day number; and
s represents the sample
number collected on test day n
3.3 It
is acknowledged that the performance of sewage treatment plants may vary considerably when the system
is tested ashore
under simulated shipboard conditions or on board a ship under actual operating conditions. Where testing ashore demonstrates that a system complies
with the standards, but subsequent onboard
testing does not meet the standards, the Administration should determine the reason and take it into account
when deciding whether to type
approve the plant.
3.4 It is recognized that Administrations
may wish to modify the specific details outlined in these Guidelines to take account
of very large, very small or unique sewage treatment
plants.
4 TECHNICAL SPECIFICATION
4.1 For
the purpose of regulations 9.1.1 and 9.2.1 of MARPOL Annex IV, a sewage treatment
plant should meet the following effluent standards when tested for its
Certificate of Type Approval
by the Administration:
.1 Thermotolerant Coliform
Standard
The geometric mean of the thermotolerant
coliform count of the samples of effluent
taken during the test period should not exceed 100 thermotolerant coliforms/100 ml as determined by membrane filter,
multiple tube fermentation or an equivalent analytical procedure.
.2 Total Suspended Solids (TSS) Standard
.1 The geometric
mean of the total suspended
solids content of the samples of effluent
taken during the test period should not exceed
35 Qi/Qe mg/l.
.2 Where the sewage treatment
plant is tested on board ship, the maximum total suspended solids content of the samples
of effluent taken during the test period may be adjusted to take account of the total suspended solid content
of the flushing water. In allowing this
adjustment in maximum TSS, Administrations should ensure
sufficient tests of TSS are taken of the flushing
water throughout the testing period to establish
an accurate geometric
mean to be used as the adjustment figure (defined as x). In no cases should the maximum allowed TSS
be greater than (35 plus x)
Qi/Qe mg/l.
Method of testing should be by:
.1 filtration of
representative sample through a 0.45 µm filter
membrane, drying at 105°C and weighing; or
.2 centrifuging of a representative sample (for at least five minutes with mean acceleration of 2,800-3,200 g), drying
at least 105°C
and weighing; or
.3 other internationally accepted equivalent test standard.
.3 Biochemical oxygen
demand without nitrification
and chemical oxygen demand
Administrations should ensure the sewage treatment
plant is designed
to reduce both soluble and insoluble organic
substances to meet the requirement
that, the geometric
mean of 5-day biochemical oxygen demand without
nitrification (BOD5 without nitrification) of the samples
of effluent taken during the test period does not exceed 25 Qi/Qe
mg/l and the chemical oxygen
demand (COD) does not exceed
125 Qi/Qe mg/l. The test method standard
should be ISO 5815 1:2003 for BOD5 without nitrification and ISO 15705:2002 for COD, or
other internationally accepted equivalent test standards.
.4 pH
The pH of the samples of effluent taken during the test period should be between
6 and 8.5.
.5 Zero or non-detected values
For thermotolerant coliforms zero values should be replaced with a value of
1 thermotolerant coliform/100 ml to allow the calculation of the geometric mean. For
total suspended solids,
biochemical oxygen demand without nitrification and chemical oxygen demand values below the limit of detection
should be replaced with one half the limit of detection to allow the calculation
of the geometric mean.
4.2 For
the purpose of regulation 9.2.1 of MARPOL Annex IV, a sewage treatment plant installed on a passenger ship intending to
discharge sewage effluent in special areas should additionally meet the following effluent
standards when tested
for its Certificate of Type Approval
by the Administration:
.1 Nitrogen and phosphorus removal
standard
The
geometric mean of the total nitrogen and phosphorus content
of the samples of effluent taken during the test period should not
exceed:
.1 total nitrogen1: 20 Qi/Qe mg/l or at least 70 per cent reduction2;
.2 total phosphorus: 1.0 Qi/Qe mg/l or at least 80 per cent reduction3.
.2 Method
of testing should be:
.1 ISO
29441:2010 for total nitrogen; and
.2 ISO 6878:2004 for total phosphorus; or
.3 other internationally accepted equivalent test standard.
__________________________________
1 Total
nitrogen means the sum of total Kjeldahl nitrogen (organic and ammoniacal
nitrogen) nitrate-nitrogen
and nitrite-nitrogen.
2 Reduction
in relation to the load of the influent.
3 Reduction
in relation to the load of the influent.
4.3 Where
the sewage treatment plant has been tested ashore, the initial survey should include installation and commissioning of the
sewage treatment plant.
4.4 A
review of the Nitrogen and Phosphorus removal standard set forth in paragraph
4.2.1 of the Guidelines should be undertaken by the Committee at its
sixty-seventh session (second part of year 2014) to determine that the required
removal standards for Nitrogen and Phosphorus are met by type approved sewage
treatment plants, or such systems in development, taking into account the
results of on board and ashore testing in accordance with section 5 of the 2012
Guidelines. In order to accomplish
this, the Committee decided to establish
a review group at MEPC 67.
4.5 The Committee, based
on the information provided by the review
group, should decide whether it is possible for ships to
comply with the standard in paragraph 4.2.1 with the dates set out in paragraph 1.2.3. If a decision is taken that it
is not possible or practicable for ships
to comply, then the Guidelines
should be amended accordingly.
5 TESTING CONSIDERATIONS
5.1 Testing of the operational performance of a sewage treatment plant should be conducted in accordance with the following
subparagraphs. Unless otherwise noted, the subparagraphs apply to testing both on board and ashore.
5.2 Raw sewage
quality
5.2.1
Sewage treatment plants tested ashore – the influent should be fresh sewage
consisting of faecal matter, urine, toilet paper and flush water to which, for
testing purposes primary sewage sludge has been added as necessary to attain a
minimum total suspended solids concentration appropriate for the number of
persons and hydraulic loading for which the sewage treatment plant will be
certified. The testing should take into
account the type of system (for example, vacuum or gravity toilets) and any
water or grey water that may be added for flushing to the sewage before treatment.
In any case the influent concentration of total suspended solids should be no
less than 500 mg/l.
5.2.2
Sewage treatment plants tested on board – the influent may consist of the
sewage generated under normal operational conditions. In any case the average
influent concentration of total suspended solids should be not less than 500
mg/l.
5.2.3
Influent should be assessed without the contribution of any
return liquors, wash water, or
recirculates, etc., generated from the sewage treatment plant.
5.3 Duration
and timing of test
The duration
of the test period should be a minimum of 10 days and should be timed to
capture normal operational conditions, taking into account the type of system
and the number of persons and hydraulic loading for which the sewage treatment
plant will be type approved. Noting that the systems need a period of
stabilization, the test should commence after steady-state conditions have been
reached by the sewage treatment plant under test.
5.4 Loading factors
5.4.1
During the test period, the sewage treatment plant should be tested under
conditions of minimum, average and maximum volumetric loadings:
.1 for testing
ashore, these loadings
should be as laid down in the manufacturer's specifications. Figure 2 shows suggested timings
for sampling each loading
factor; and
.2 for testing
on board, minimum
loading should represent
that generated by the number of persons on the ship when it is
alongside in port, and average and maximum
loadings should represent
those generated by the number of persons
on the ship at sea and should take account
of meal times and watch
rotations.
5.4.2
The Administration should undertake to assess the capability of the sewage
treatment plant to produce an effluent in accordance with the standards
prescribed by section 4 following minimum, average and maximum volumetric
loadings. The range of conditions under which the effluent standards were met
should be recorded on the Certificate of Type Approval. The form of the
Certificate of Type Approval and appendix is set out in the annex to these
Guidelines.
5.5 Sampling methods
and frequency
5.5.1
Administrations should ensure
that the sewage
treatment plant is
installed in a manner which
facilitates the collection of samples, see figure 1. Sampling should be carried
out in a manner and at a frequency which is representative of the effluent
quality. Figure 2 provides a suggested frequency for sampling, however, the
frequency should take account of the residence time of the influent in the
sewage treatment plant. A minimum of 40 effluent samples should be collected to
allow a statistical analysis of the testing data (e.g. geometric mean, maximum,
minimum and variance).
5.5.2 Influent sample point should be
upstream of any return liquors, wash water, or recirculates generated from the
sewage treatment plant. Where such a sample point is not readily available on
ships, the flows and concentrations of these return liquors, wash water, or
recirculates generated from the sewage treatment plant should be measured, so
that the load can be taken away from the load of influent.
5.5.3 An influent sample should be taken and analysed for every effluent
sample taken and the results recorded to ensure
compliance with section 4. If possible, additional influent and effluent samples
should be taken to allow for a margin of error. Samples
should be appropriately preserved prior to analysis particularly if there is to be a significant delay between
collection and analysis or during times of
high ambient temperature.
5.5.4 Any
disinfectant residual in samples should
be neutralized when the sample
is collected to prevent unrealistic bacteria kill or chemical oxidation
of organic matter by the disinfectant brought
about by artificially extended contact times. Chlorine (if used) concentration and pH should be
measured prior to neutralization.
Figure
2: Suggested hydraulic loading factors and sampling frequency for testing
sewage treatment plants. May be
modified as necessary to take account of characteristics of individual sewage
treatment plants
5.6 Analytical testing
of effluent
The Administration should give
consideration to the recording of other parameters in addition to those required
(thermotolerant coliforms, total
suspended solids, BOD5 without nitrification, COD, pH and residual
chlorine) with a view to future technological development. These parameters include
total solids, volatile
solids, settleable solids,
volatile suspended solids, turbidity, total organic carbon, total coliforms
and faecal streptococci.
5.7 Disinfectant residual
The potential adverse
environmental effects of many disinfectant residuals and by-products, such as those associated with the use of chlorine
or its compounds, are well recognized. It is, therefore, recommended that Administrations encourage
the use of ozone, ultraviolet irradiation or any other disinfectants which minimize adverse
environmental effects, whilst pursuing
the thermotolerant coliform standard. When
chlorine is used as a disinfectant, the Administration should be satisfied
that the best technical practice
is used to keep the disinfectant residual
in the effluent below 0.5 mg/l.
5.8 Scaling considerations
Only
full-scale marine sewage treatment plants should be accepted for testing
purposes. The Administration may certify a range of the manufacturer's
equipment sizes employing the same principles and technology, but due
consideration should be given to limitations on performance which might arise
from scaling up or scaling down. In the case of very large, very small or
unique sewage treatment plants, certification may be based on results of
prototype tests. Where possible, confirmatory tests should be performed on the
final installation of such sewage treatment plants.
5.9 Environmental testing
of the sewage treatment plant
5.9.1
The Administration should ensure that the sewage treatment plant can operate
under conditions of tilt consistent with internationally acceptable shipboard
practice up to 22.5º in any plane from the
normal operating position.
5.9.2
Tests for certification should be carried out over the range of salinity and
the range of temperatures for ambient air and flush water specified by the
manufacturer, and the Administration should be satisfied that such
specifications are adequate for the conditions under which the equipment must
operate.
5.9.3 Control and sensor components should be subjected
to environmental testing
to verify their suitability for marine use. The Test Specifications section
in part 3 of the annex to the Revised
Guidelines and Specifications for Pollution Prevention Equipment for Machinery
Space Bilges of Ships (resolution MEPC.107(49)) provides guidance
in this respect.
5.9.4
Any limitation on the conditions of operation should be recorded on the
certificate.
5.9.5
The Administration should also consider requiring the manufacturer to include
in the operating and maintenance manuals, a list of chemicals and materials
suitable for use in the operation of the sewage treatment plant.
5.10 Other considerations
5.10.1 The
type and model of the sewage treatment
plant and the name of the manufacturer should be noted
by means of a durable
label firmly affixed
directly to the sewage
treatment plant. This label should
include the date of manufacture and any operational or installation limits
considered necessary by the manufacturer or the Administration.
5.10.2 Administrations should examine the manufacturer's installation, operating and maintenance
manuals for adequacy
and completeness. The ship should have on board at all times a manual detailing the operational and maintenance procedures for the sewage treatment
plant, including safety information about the chemicals and materials actually
used in the operation of the sewage
treatment plant.
5.10.3 Qualifications of testing facilities
should be carefully examined by the Administration as a prerequisite to their participation in the testing
programme. Every attempt
should be made to assure uniformity among the various
facilities.
6 RENEWAL AND ADDITIONAL SURVEYS
Administrations should endeavour to
ensure, when conducting renewal or additional surveys in accordance with regulations 4.1.2
and 4.1.3 of MARPOL Annex
IV, that the sewage treatment
plant continues to perform in accordance with the conditions outlined in regulation 4.1.1 of MARPOL Annex IV.
7 FAMILIARIZATION OF SHIP PERSONNEL IN THE USE OF THE
SEWAGE TREATMENT PLANT
Recognizing that the appropriate regulations relating to familiarization are contained within the Ships Safety Management Systems under the International Safety Management Code, Administrations are reminded that ship staff
training should include
familiarization in the operation and maintenance
of the sewage treatment plant.
8 MAINTENANCE
Routine maintenance of the system should be clearly
defined by the manufacturer in the associated operating and maintenance
manuals. All routine and repair maintenance should be recorded.
|
ANNEX FORM OF CERTIFICATE OF TYPE APPROVAL FOR SEWAGE
TREATMENT PLANTS AND
APPENDIX
NAME OF ADMINISTRATION CERTIFICATE
OF TYPE APPROVAL FOR SEWAGE TREATMENT PLANTS This is to
certify that the sewage treatment plant, type ................................................................................., having a designed hydraulic loading of ........................ cubic
metres per day, (m3/day), an organic loading of ............ kg per day
biochemical oxygen demand without nitrification (BOD5 without nitrification) and of the design shown on drawings Nos. ..................................................................................................................... manufactured by ............................................................................................................................................. has been examined and satisfactorily tested
in accordance with the International Maritime Organization resolution MEPC.227(64) to meet the operational requirements referred to in regulations 9.1.1
and 9.2.1 of MARPOL Annex
IV of the International Convention for the Prevention of Pollution from
Ships, 1973, as modified by the 1978
and 1997 Protocols (as amended by resolutions MEPC.115(51) and MEPC.200(62)). The tests on the sewage treatment plant were carried
out ashore
at*...................................................................................................................................................... on board
at*...................................................................................................................................................... and completed on .......................................................................................................................................... The sewage treatment plant was tested
and produced an effluent which,
on analysis, produces: .1 a
geometric mean of no more than 100 thermotolerant coliforms/100 ml; .2 a
geometric mean of total suspended solids of 35 Qi/Qe mg/l if tested ashore or
the maximum total suspended solids
not exceeding (35 plus x)
Qi/Qe mg/l for the ambient
water used for flushing purposes if tested on board; .3 a
geometric mean of 5-day biochemical
oxygen demand without nitrification (BOD5 without
nitrification) of no more than 25 Qi/Qe
mg/l; .4 a geometric mean
of
chemical oxygen demand
(COD) of no more than 125 Qi/Qe
mg/l; .5 pH
between 6 and 8.5; .6 a geometric mean of total
nitrogen of no more than 20 Qi/Qe
mg/l or at least 70 per cent reduction; and .7 a geometric mean of total
phosphorus of no more than 1.0 Qi/Qe mg/l or at least 80
per cent reduction**. The Administration confirms that the sewage treatment
plant can operate at angles of inclination of 22.5° in any plane from the
normal operating position. Details of the tests and the results obtained are shown
on the appendix to this Certificate.
_______________________ * Delete as appropriate. ** Delete for ships other than passenger
ships intending to discharge sewage effluent in Special Areas. A plate or durable label containing data of the
manufacturer's name, type and serial numbers, hydraulic loading and date of manufacture should be fitted
on each sewage treatment plant. A copy of this certificate should be carried on board any
ship equipped with
the above described
sewage treatment plant. Official stamp Signed ..................................................................................................... Administration of ……………………………………......... Dated this ………............… day of..…….........……..… 20……..... |