gross tons and those of less than 400 gross tons carrying 15 or more passengers may be issued a certificate

every five years, endorsed annually. This is true for all

but small passenger vessels (i.e., 46 CFR Subchapter

T and K), which receive an endorsement on their certificate of inspection every five years, endorsed annually. Equipment and testing requirements are

similar to those detailed above for a U.S. vessel on a

U.S. voyage.

For a non-U.S. vessel on a U.S. voyage, sewage regulations can be found in the prior MARPOL Annex

IV with an equivalency made to 33 CFR Part 159 by

Navigation and Vessel Inspection Circular No. 9-82,

Change 1. In this case, the U.S. Coast Guard verifies

the vessel’s certificate of type test during a port state

control examination.

Revised International Sewage Regulations

In 2004, the Marine Environment Protection Committee (MEPC) of the International Maritime Organization (IMO) adopted and reissued the revised

MARPOLAnnex IV in resolution MEPC.115(51), resulting in several key changes to the international

sewage regulations:

· Inspection criteria were enhanced to include

onboard surveys of installed sewage systems

prior to being placed into service and periodically throughout the life of the vessel.

· Standards for discharging treated sewage (i.e.,

effluent) into the water were enhanced and

made more stringent.

· Equipment testing procedures were standardized.

· Discharge rates for untreated sewage were established.

The IMO adopted MEPC.115(51) on April 1, 2004, and

is applicable to new ships on international voyages

with a keel laid date on or after September 27, 2003, or

delivered on or after September 27, 2006, and existing

ships after September 27, 2008, that are 400 gross tons

and above or that are certified to carry more than 15

persons. The term “person” is defined here to include

both passengers and crew.Annex IV requires ships that

engage in international voyages to be equipped with

one of the following: a sewage treatment plant; a

sewage comminuting and disinfecting system with

holding tank, or a sewage holding tank.

UnderAnnex IV, the discharge of sewage into the sea is

prohibited except when:

www.uscg.mil/proceedings Proceedings Winter 2008-09 67

tion to the satisfaction of a Coast Guard boarding officer. Equipment is subject to design approval to verify it

meets the requirements of 33 CFR Part 159 (or an equivalency) and then undergoes testing, evaluation, and inspection by an independent laboratory under

simulated operating conditions. Equipment manufactured in the United States meeting both U.S. and internationalrequirements may be eligible for a certificate of

type approval. Finally, testing facilities that meet the requirements of independent laboratory testing standards in 46 CFR 159.010-3 are issued a U.S. Coast

Guard letter of acceptance.

For a U.S.-flagged vessel on an international voyage,

sewage regulations covering the vessel, its equipment,

and related testing requirements can also be found in 33

CFR Part 159 with a concomitant equivalency made to

MARPOLAnnex IV by MOC policy letter 03-03. In this

case, the U.S. Coast Guard issues a certificate of equivalency to a U.S.-flagged vessel on an international voyage having an installed and operational MSD.

Uninspected vessels over 400 gross tons are issued a certificate every five years, endorsed annually during the

IOPP (international oil pollution prevention) survey, or

can receive a statement of voluntary compliance from

their classification society. Inspected vessels over 400

Oxidation/Reduction MSD. Courtesy Navalis Environmental Systems.

Recent changes to international regulations that govern discharge of ships’ sewage into the sea have left

many people wondering if the United States will formally adopt the new standards and, if it does, how

such action might impact the industry at large. Vessel

owners and operators, shipyards, and boat builders;

manufacturers of marine sanitation devices and

sewage treatment plants; and the independent laboratories that test such equipment are all concerned about

the status of MARPOLAnnex IV in the United States.

While it may be too soon to predict when or even if the

United States will ratify the sewage annex, everyone

involved can agree that a clear understanding of both

U.S. and international sewage regulations is necessary

to avoid running afoul of the enforcement authorities

both here and abroad.

Sewage regulations can easily be broken down into

three discrete categories covering vessels, equipment,

and testing facilities. These regulations can then be

placed into one of three different scenarios:

· a U.S.-flagged vessel on an international voyage,

· a U.S.-flagged vessel on a U.S. voyage,

· a non-U.S.-flagged vessel on a U.S. voyage.

These regulations affect nearly all types of vessels, from

the larger inspected vessels that carry passengers and

cargo, to the smaller uninspected vessels that tow ships

and barges, to even private vessels such as yachts and

recreational vessels. In essence, any vessel with an installed toilet may be subject to these requirements.

U.S. Sewage Regulations and Related Policies

For a U.S.-flagged vessel on a U.S. voyage, existing

sewage regulations covering the vessel, its equipment,

and related testing requirements can be found in 33

CFR Part 159. These regulations have not changed

much since they were first introduced in 1975, with the

exception of those for the cruise ship industry operating in certain Alaskan waters.

1

Inspected vessels with an installed marine sanitation

device (MSD) are examined by the U.S. Coast Guard

during annual and five-year certificate of inspection renewals. Uninspected vessels (which include recreational vessels) with an installed MSD are checked

periodically to ensure the device is in operable condi66 Proceedings Winter 2008-09 www.uscg.mil/proceedings

Greenwater

The future of

sewage regulations,

equipment design, and testing.

by LT ROB GRIFFITHS

U.S. Coast Guard Office of Design and Engineering Standards

COMMANDER STEPHEN P. MARKLE, USN (RET.), P.E.

Engineering Director

Navalis Environmental Systems

Aerobic digestion of sewage waste by biological device.

Courtesy TEi-Testing Services.

MR. MATTHEW D. MACGREGOR

Executive Director

TEi-Testing Services

ON

THE

SURFACE

ON

THE

SURFACE

Environmental

Protection
eliminated. The effluent standards

alone in MPEC.2(VI), when compared

to MEPC.159(55), are not only numerically different but also appear to be

substantially different. See the comparison between the current sewage

regulations and the revised internationalregulations in Tables 1, 2, and 3.

Equipment Design and

Manufacturing

The design of a wastewatertreatment

system is fundamentally the same for

both land- and marine-based systems. Most successful designs follow

a rule of thumb by firstremoving that

which settles and that which floats,

and then treat the remaining 95 percent of liquid, referred to as “mixed

liquor.”At this point,roughly 90 percent of the treatment challenge has already been accomplished, leaving the

dissolved and suspended material

for subsequent processing. It is therefore useful to break down the regulatory requirements into functional

system requirements in orderto meet

the discharge standards. These requirements exist as six discrete functions, as depicted in Figure 1.

While land-based sewage treatment

systems have incorporated these

steps in a variety of ways, only recently has regulatory action required

the manufacturers of marine systems

to consider such functional requirements. For example, sludge or bioresidue is the byproduct of those

systems that produce the highestquality effluent. Management has

typically been to dump it at sea

where permitted, bring it ashore, or

with limited success, incinerate it onboard. However, for those systems

that treat to a less stringent standard,

the effluent is typically discharged

overboard either as part of the

process or where legally permitted to

do so.

www.uscg.mil/proceedings Proceedings Winter 2008-09 69

1. Type III MSD used for storage of sewage/flushwater at ambient air pressure/temperature has no certification number/label under 33CFR159.12a; inspected vessels comply with 46CFR Subchapters F & J.

COMPARISON OF SEWAGE REGULATIONS

COMPARISON OF SEWAGE REGULATIONS

· The ship has in operation an approved sewage

treatment plant.

· The ship is discharging comminuted and disinfected sewage using an approved system at

a distance of more than three nautical miles

from the nearest land.

· The ship is discharging

sewage that is not comminuted or disinfected (untreated) at a distance of

more than 12 nautical miles

from the nearest land.

The term “sewage” includes

drainage and other wastes from toilets and urinals; drainage from medical spaces including wash basins,

wash tubs, and scuppers located in

such spaces; drainage from spaces

containing live animals; and other

waste water, when mixed with any

of these drainages.

Additionally, on October 13, 2006,

resolution MEPC.159(55) adopted

the revised effluent standards and

performance tests that are applicable

to new installations of sewage treatment plants for new ships

with a keel laid date on or after

January 1, 2010, and for existing ships having plants installed or delivered on or after

January 1, 2010. Existing ships

having sewage treatment

plants installed or delivered

prior to that date may continue to use either the 1976 international effluent standards

contained in MEPC.2(VI) or

other applicable national specifications (e.g., 33 CFR Part

159).

Finally, on October 13, 2006,

resolution MEPC.157(55)

adopted a standard for the

maximum rate of discharge of

untreated sewage in holding

tanks at a distance equal to or

greater than 12 nautical miles

from the nearest land.

Prior Equivalency

Considering the recent changes to MARPOL Annex IV,

it may well be that the prior equivalency afforded U.S.-

flagged vessels on international voyages has been all but

68 Proceedings Winter 2008-09 www.uscg.mil/proceedings

Mobile testing laboratory for compliance testing. Courtesy TEi-Testing Services.

1. Type III MSD used for storage of sewage/flushwater at ambient air pressure/temperature has no certification number/label under 33CFR159.12a; inspected vessels comply with 46CFR Subchapters F & J.

COMPARISON OF SEWAGE REGULATIONS
www.uscg.mil/proceedings Proceedings Winter 2008-09 71

effective at disinfecting the effluent. Typical effluent

values are below detection for suspended solids and

fecal coliform, and average five-day biochemical oxygen demand is below five milligrams per liter.

2

Subsequent system development has led to an ozonebased sludge management system that reduces the volume of organic solids through oxidation butincreases the

settleability of solids, thus allowing a higher-content

sludge thatis partially disinfectedand mineralized.These

systems are now being adapted to marine use, having already proven themselves in land-based sewage treatment

systems as well as graywater reuse applications.

The future of reusing water aboard ships looks promising. In the previously mentioned system, blackwater

consisting of sewage and galley water can be treated in

a system separate from graywater. By separating out

the water in laundry and hotel accommodations, treatment becomes greatly simplified and produces an effluent that is suitable for reuse aboard the ship as

technical water. Treated water3 can be readily used in a

ship’s laundry, for engineroom technical water, as a

source for fuel oil emulsification for engine oxides of

nitrogen reduction, orfor deck washdown and the like.

With the ability to treat upwards of 80 percent of shipboard domestic wastewater, future systems may eventually lead to reduced fuel consumption from water

generation, storage, and transport. Perhaps we can

have smaller ship sizes, given reduced requirements for

tankage, and even reduced operational costs through

lower maintenance of water management technology.

Compliance Testing

Initial qualification testing evaluates mechanical and

electrical performance as well as effluent processing.

The mechanical and electrical performance requirements are based on a device’s ability to withstand the

rigors of the marine environment such as corrosion, vibration, and incidental impacts. The new international

requirements for such testing are not much different

from current requirements and therefore will not be

presented here.

There is, however, a substantial difference in effluent

processing performance during the initial qualification

testing. First, the device manufacturer should consider

where the device will be placed into service (coastal, intercoastal, etc.). Second, consideration should be given

to the type of device. For example, if you have a comminuting/disinfecting system that simply transforms

the sewage into an effluentreduced in size, which then

disinfects to prevent the spread of harmful pathogens

but keeps its original nutrient value, this produces an

effluent that must be discharged beyond three nautical

miles from shore. That is different from a treatment device that firstreduces the sewage bio-limiting nutrients

through biological digestion or oxidation and then disinfects the effluent to prevent propagation of harmful

pathogens, which would produce an effluent that can

be discharged within three nautical miles from shore.

Another type of device might be a totally “green” device with an environmentally compatible effluent that

not only addresses bio-limiting nutrients using an alternate disinfection method, but also is capable of reducing both graywater and blackwater effluents to a

zero ecological effect on the aquatic system, thus producing an effluent that can be discharged virtually anywhere, including in designated no discharge zones. To

decide which system is best for a given application, a

background in processing testing may be helpful.

Processing testing is based on the ability of a given device to affect the basic composition of sewage that has

physical, chemical, and biological elements. Testing for

these elements is done using three types of analysis—

physical, chemical, and biological challenges.

Physical testing determines the amount of matter discharged in the effluent which is made up of the solid

residues found in sewage such as fibrous, cellular, and

foreign material. Testing looks for the amount of total

solids untreated by the MSD that are subsequently

passed into the environment.

Chemical testing determines the amount of natural and

introduced chemicals found in the influent. These

chemicals constitute what is known as bio-limiting nutrients and hazardous materials. Bio-limiting nutrients

are naturally occurring in human waste and, if untreated, promote unwanted growth in an aquatic system. These bio-limiting nutrients are determined by

testing for chemical oxygen demand, nitrogen, phosphorus, and total organic carbons.

Hazardous chemicals include those used to treat waste

such as disinfectants or chemicals found in graywater

that are introduced into the MSD. Testing for residues

indicates the presence of hazardous chemicals, which

drastically affects the acidity, alkalinity, chlorides, pH,

semi-volatiles, volatiles, and other analytical methodology. The type and amount of analysis done is based

Making the transition from functional requirements to

engineering specifications requires a firm understanding of process chemistry as well as material standards.

U.S. regulations offer several sections with robust design guidance. Similarly, ASTM standard F 2363-06,

specification for United States Coast Guard type II, or

IMO MARPOL 73/78 Annex IV marine sanitation devices (flow-through treatment) offers specific materials

and testing requirements for these types of systems.

Today, most marine systems employ biologic activities

that remove dissolved organic material. These systems

employ bio-reactors that are exceptionally sensitive to

influent loading from hydraulics and pollutants. Hydraulic loading is handled through equalization tanks

and onboard flow management to ensure the system

receives a fairly constantrate of influent. The more successful biological systems are coupled with chemical

equalization to maintain constant nutrient loading.

What is difficult to plan for are upsets caused by the introduction of cleaning and disinfecting products commonly used throughout the ship that harm the bacteria

in the bio-reactor.

Modern biological systems can be grouped into one of

three categories:

· systems thatremove solids using dissolved air

flotation and remove suspended solids by flocculation and mechanical means;

· systems having high concentrations of solids

as measured by mixed liquor suspended solids

using membrane technology to filterthe water;

· systems that operate primarily on the principle of gravity-driven clarification, where gravity causes suspended matter to fall out,

resulting in clarified material passing over a

wall or weir and onto the next step, which is

typically disinfection.

70 Proceedings Winter 2008-09 www.uscg.mil/proceedings

When operated within strict guidelines, these systems

generally produce excellent effluent, but are susceptible

to periodic upset and require not only large quantities

of air to maintain the bio-reactor but also large tanks.

While most systems still employ chlorination disinfection, some have recently switched to ultraviolet (UV)

light-based systems forthis function.Although UV systems are very effective at disinfecting highly clarified

water, biological treatment systems often produce effluent with color or turbidity that diminish the effectiveness of this technology.

Another marine system commonly used today is the

physical/chemical type. These systems macerate incoming wastewater, then mix it with high concentrations of chlorine-containing compounds that are

typically generated from seawater. These systems rely

on chlorine to oxidize a fraction of the organic material

and to disinfect. Many of these systems also introduce,

as process water, the seawater that was used to generate the chlorine compounds. Some systems use 10 times

the amount of process water compared to the amount

of wastewater being treated and are typically found on

smaller vessels where available space is at a premium.

Increased effluent quality standards coming into force

over the next several years will create serious challenges for smaller systems of this type, especially for

residual chlorine content and removal of solids and nutrient material.

A third type of system has recently entered both the

large and small ship markets, receiving USCG certification as a Type II MSD in January of 2008. This system

is based on advanced oxidation to remove dissolved

pollutants in wastewater. The trick here is to remove

the particulate organic and inorganic material to offer

the oxidizer an easier target.

Solids are first screened, flocculated, filtered, and then ultra-filtered to produce a permeate with

turbidity approaching one NTU

(nephelometric turbidity unit).

The permeate is then brought

into contact with dissolved ozone

gas in a stirring device where oxidation of dissolved material occurs. The ozonated water is then introduced into a

high-power UV system that converts the residual

ozone gas to a highly reactive oxygen species that further polishes the effluent. This process not only removes residual organic material, but is also highly

Figure 1.
on the extent of purity desired for the effluent. For example, you would not test for chemicals not listed in

the regulation unless you wanted to demonstrate the

purity of the effluent for possible use of a MSD in a “no

discharge” zone.

Biological testing determines the amount of natural

pathogens found in human waste. These pathogens

constitute harmful microorganisms that promote illness

and use available oxygen, thus limiting or destroying

the growth within the natural aquatic system. These

microorganisms are determined by testing for biological oxygen demand and thermotolerant coliforms.

Another factor in MSD design involves dilution. The

U.S. Environmental ProtectionAgency strictly prohibits

the use of dilution to reduce effluent to meet discharge

requirements. Although dilution is not applicable to

comminuting/disinfecting devices, the amount of processing water used by an MSD indicates whether it is a

dilution device. If the ratio of process water to influent

water is greater than 5:1 when cycled, an investigation

should be made as to whether the MSD is using dilution to meet the discharge requirements.

It is important to realize that design approval and certification indicates a device is capable of meeting discharge regulations, but does not necessarily guarantee

that a given device will always meet the discharge requirements. The condition, maintenance, and operation

of the MSD all affect the quality of the effluent. When

properly maintained and operated, most MSDs willremain compliant with the discharge criteria, but should

be tested periodically to verify compliance.

The future of testing will be based on using analytical

methods that will evaluate the MSD effluent to ensure

minimum effect on the aquatic system to the extent that

all physical, chemical, and biological elements of shipboard graywater and blackwater have been removed or

otherwise neutralized. Only then will the most sensitive

of aquatic systems be unaffected by the passage of a

ship, thus creating a more earth-friendly environment.

About the authors:

LT Rob Griffithsis a mechanicalengineerin the U.S. Coast Guard’s Office of Design and Engineering Standards, where he oversees the independent testing labs and related equipment approvals for shipboard

sewage treatment systems and pollution prevention equipment. He has

served 21 years in the Coast Guard, including assignments as a marine

inspector and chief of waterways management in Los Angeles/Long

Beach, migrant interdiction officerin Miami,search and rescue controller

in San Diego, operations officer and law enforcement boarding officer on

a patrol boat in Miami, and as a quartermaster on a medium endurance

cutter in St. Petersburg, Fla. He is a 2007 graduate of the Naval Postgraduate School in Monterey, Calif., where he received his master of science degreein mechanicalengineering, and a 1999 graduate of San Diego

State University, where hereceived his bachelor ofscience degreein criminal justice.

Commander Stephen P. Markle, P.E., is a retired U.S. Navy engineering duty officer and is the engineering director for Navalis Environmental Systems. He is a 1993 graduate of the Naval Construction and

Engineering program at the Massachusetts Institute of Technology,

where hereceived a navalengineer’s degree and master ofscience degree

in mechanical engineering. He is a professional engineer registered in

the state of New York and commonwealth of Virginia. He serves as the

chair of the joint ASNE/SNAME committee on environmental engineering and also as chair of ASTM ships and marine technology—marine environmental protection subcommittee.

Mr. Matthew D. MacGregor is the executive director of TEi-Testing

Services, LLC. Mr. MacGregor has over 25 years experience in testing

and is a technical expert for marine sanitation devices, bilge separators,

and oil content monitors and has served as a professional services advisor for the U.S. State Department and the U.S. Coast Guard at United

Nations IMO proceedings. Mr. MacGregor holds both a bachelor’s and

master’s degree. Mr. MacGregor is also a LTC in the U.S. Army Reserves and has completed the U.S. Army command and general staff

college. LTC MacGregor is a master aviator and has over 2,500 hours

flying military aircraft. His current qualification is in the AH-64A

“Apache” helicopter.

Bibliography

Regulations for Prevention of Pollution by Sewage from Ships, Revised

Annex IV MARPOL 73/78, adopted by MEPC.115(51) on April 1, 2004.

Effluent Standards and Performance Tests for Sewage Treatment Plants,

adopted by MEPC.159(55) on October 13, 2006.

Specifications for Environmental Testing for Type Approval of Pollution Prevention Equipment, Annex: Part 3, adopted by MEPC.107(49) on July 18, 2003.

Standards for the Rate of Discharge of Untreated Sewage from Ships, adopted

by MEPC.157(55) on October 13, 2006.

33 Code of Federal Regulations Part 159

American Public Health Association, American Water Works Association, &

Water Environment Federation, “Standard methods for the examination of

water and wastewater (21st ed.),” 2005.

Metcalf & Eddy; G. Tchobanoglous, F.L. Burton; & H.D. Stensel, “Wastewater

engineering: Treatment and reuse (4th ed.),” Boston: McGraw-Hill, 2003.

Endnotes:

1. In 2001, a new Subpart E was added to 33 CFR Part 159 to implement “Title

XIV—Certain Alaskan Cruise Ship Operations” governing the discharges of

sewage and graywater from cruise vessels, requiring sampling and testing

of sewage and graywater discharges, and establishing reporting and recordkeeping requirements. This subpart applies to each cruise vessel authorized to carry 500 or more passengers operating in the waters of the

Alexander Archipelago and the navigable waters of the United States within

the State of Alaska and within the Kachemak Bay National Estuarine Research Reserve.

2. Development of this system is further described in “Design and Prototype

Development of Advanced Oxidation Black and Gray Water Treatment Systems,”

presented at the American Society of Naval Engineers (ASNE) Marine Environmental Engineering Symposium in January 2006 and published in

Naval Engineers Journal, Volume 118, Number 3, 2006, pp. 51-64(14).

3. E.g., “California Code of Regulations Title 22” water reuse criteria.

72 Proceedings Winter 2008-09 www.uscg.mil/proceedings