United States Environmental Protection Agency

Office of Wastewater Management

Washington, DC 20460

EPA-800-R-11-001

November 2011

Graywater Discharges from 

Vessels
Graywater Discharges from Vessels Table of Contents

i

Table of Contents

Page

1 INTRODUCTION .................................................................................................................... 1

1.1 What is Graywater?................................................................................................. 1

1.2 Regulatory Framework for Graywater Discharges................................................. 2

2 GRAYWATER CHARACTERISTICS ......................................................................................... 6

3 CURRENT GRAYWATER MANAGEMENT PRACTICES........................................................... 13

3.1 Graywater Management for Large Cruise Ships .................................................. 13

3.2 Graywater Management for Medium Cruise Ships and Large Ferries................. 13

3.3 Graywater Management for Commercial Vessels on the Great Lakes................. 14

3.4 Graywater Management for Other Vessels........................................................... 14

4 GRAYWATER CONTROL STRATEGIES ................................................................................. 17

5 SUMMARY.......................................................................................................................... 24

6 REFERENCES ...................................................................................................................... 26
Graywater Discharges from Vessels List of Tables

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LIST OF TABLES

Page

1 Graywater Definitions..........................................................................................................2

2 Estimated Annual Graywater Generation by Commercial Vessels Greater Than 79 

Feet in Length in U.S. Waters..............................................................................................7

3 Percentage of Large Cruise Ship Untreated Graywater and Treated Sewage 

Samples by Concentration Range ........................................................................................9

4 Analyte Concentrations Measured in Untreated Graywater from Large Cruise 

Ships in Alaska and Armed Forces Vessels.......................................................................10

5 Analyte Concentrations Measured in Untreated Graywater from Small Cruise 

Ships and Large Ferries in Alaska .....................................................................................11

6 Analyte Concentrations Measured in Untreated Graywater from Fishing Vessels 

and Non-Recreational Vessels Less Than 79 Feet in Length ............................................12

7 Vessel Operators Contacted to Discuss Graywater Management Practices......................16

8 Vessel Sewage Treatment System Vendors Contacted to Discuss Graywater 

Treatment Claims...............................................................................................................19

9 Vessel Sewage Standards under Various U.S. and International Regimes........................21

10 Average Treated Effluent Data For Five Alaska Marine Highway Vessels 

Treating Comingled Sewage and Graywater.....................................................................22

11 Large Cruise Ships AWTS Influent and Effluent Concentrations and Percent 

Removals............................................................................................................................23

The EPA technical contacts for this document are Ryan Albert (202) 564-0763 and Juhi Saxena 

(202) 564-0719.
Graywater Discharges from Vessels Section 1 - Introduction

1

SECTION 1

INTRODUCTION

The 2008 Vessel General Permit (VGP) regulates discharges incidental to the normal 

operation of vessels operating as a means of transportation.

Because EPA plans to reissue the VGP, the Agency continues to gather information on 

vessel wastewater sources while examining technologies that can be used to remove pollutants 

before discharge into waters of the United States.

The VGP, like other general permits,

is issued by the permitting authority (in this case, EPA) and covers multiple facilities within a 

specific category for a specific period of time (not to exceed 5 years). The 2008 VGP includes 

the following limits or requirements: general effluent limits applicable to all discharges; effluent 

limits applicable to 26 specific discharge streams; narrative water-quality based effluent limits; 

inspection, monitoring, recordkeeping, and reporting requirements; and additional requirements 

applicable to certain vessel types (USEPA, 2008a).

1

1.1 WHAT IS GRAYWATER?

This document contains updated information 

on both vessel graywater discharge characteristics and recent developments in graywater 

treatment technologies. 

For purposes of the 2008 VGP, “graywater” means galley, bath, and shower water, as 

well as wastewater from lavatory sinks, laundry, and water fountains (USEPA, 2008a). Other 

regulations have expanded the definition of graywater to specifically include discharges from 

dishwashers. Table 1 shows various other definitions for graywater based on different 

regulations (USEPA, 2008b). According to information gathered by EPA during ship visits and 

via responses to EPA’s survey of cruise ships operating in Alaska in 2004, the following waste 

streams were routed to the graywater system:

2

 Wastewater from bar and pantry sinks;

 Wastewater from salon and day spa sinks and floor drains;

 Wastewater from interior deck drains, shop sinks, and deck drains in non-engine rooms; 

 Refrigerator and air conditioner condensate; 

 Wastewater from laundry floor drains in passenger and crew laundries; 

 Dry cleaning condensate; 

 Wastewater from garbage room floor drains and from sinks in restaurants and cafes;

 Wastewater from whirlpools; and 

 Wastewater from medical facility sinks and medical floor drains. 

These waste streams are not specifically listed in the 2008 VGP graywater definition, or 

within other regulatory definitions of graywater listed in Table 1, although some have similar 

characteristics. For example, wastewater from bar and pantry sinks would be expected to have 

characteristics similar to dishwasher wastewater. 

 1 “Waters of the United States” as defined in 40 CFR 122.2. 2 Note that the 2008 VGP prohibits some of the sources below from being discharged into waters subject to that 

permit.
Graywater Discharges from Vessels Section 1 - Introduction

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Table 1. Graywater Definitions

Source Graywater Definition

Clean Water Act, 33 U.S.C. §

312(a)(11)

Galley, bath, and shower water

International Maritime Organization 

Guidelines for Implementation of 

Annex V of MARPOL

Drainage from dishwasher, 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 Annex IV, as well as drainage 

from cargo spaces

Title XIV – Certain Alaskan Cruise 

Ship Operations, 33 U.S.C. § 1901 

Note (Sec. 1414(4))

Only galley, dishwasher, bath, and laundry wastewater

Coast Guard regulations

implementing MARPOL and the Act 

to Prevent Pollution from Ships, 33 

CFR 151.05

Drainage from dishwasher, shower, laundry, bath, and washbasin drains 

and does not include drainage from toilets, urinals, hospitals, and cargo 

spaces

Graywater discharges can contain bacteria, pathogens, oil and grease, detergent and soap 

residue, metals (e.g., cadmium, chromium, lead, copper, zinc, silver, nickel, and mercury), 

solids, and nutrients (USEPA, 2008b; USEPA 2010). Wastewater from medical facility sinks and 

medical floor drains may contain constituents ranging from bacteria, nutrients, and oxygendepleting substances (e.g., BOD5), depending on the types of illness or treatment procedures 

being performed. 

1.2 REGULATORY FRAMEWORK FOR GRAYWATER DISCHARGES

Graywater discharges from vessels operating in U.S. waters have historically been 

excluded as discharges incidental to the normal operation of a vessel from Clean Water Act 

(CWA) National Pollutant Discharge Elimination System (NPDES) permitting requirements 

through regulations at 40 CFR 122.3(a). However, in December 2003, the long-standing 

exclusion of discharges incidental to the normal operation of vessels from the NPDES program 

became the subject of a lawsuit in the U.S. District Court for the Northern District of California. 

On March 30, 2005, the same court determined that the exclusion exceeded the Agency’s 

authority under the CWA, and issued a court order vacating that exclusion. As a result, 

discharges incidental to the normal operation of a vessel, including graywater, became subject to 

CWA section 301’s prohibition against discharging without a NPDES permit, unless covered 

under an NPDES permit. On December 19, 2008, EPA issued the VGP to provide NPDES 

permit coverage for vessel discharges incidental to normal operation from commercial vessels 

greater than 79 feet into waters of the United States. Waters of the United States, as defined in 40 

CFR 122.2, includes the 3-mile territorial sea as defined in Section 502(8) of the CWA, and 

inland navigable waters, including navigable waters of the Great Lakes subject to the jurisdiction 

of the United States (USEPA, 2008a). The 2008 VGP did not include discharges incidental to 

normal operation of vessels less than 79 ft and commercial fishing vessels3, which are exempt 

from NPDES permitting until December 2013,

4

 3 Except for ballast water discharges, for which these vessels still required NPDES permit coverage

pursuant to a moratorium. Approximately 

120,000 to 140,000 vessels fall under the moratorium, including commercial fishing vessels and 

4 Public Law (P.L.) 110-299, amended by P.L. 111-215.
Graywater Discharges from Vessels Section 1 - Introduction

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those commercial vessels 79 feet or less in length. Discharges from recreational and armed 

forces vessels are also permanently excluded.

5

The 2008 VGP includes several best management practices (BMPs) that EPA determined 

are practicable and achievable for the control of graywater impacts (USEPA 2008a). First, all 

vessels must minimize the production and discharge of graywater while in port. For vessels that 

cannot store graywater, the owner or operator should minimize graywater generation while in 

port. Second, vessels greater than 400 gross tons that regularly travel more than 1 nautical mile 

(nm) from shore and have the capacity to store graywater must discharge graywater greater than 

1 nm from shore while the vessel is underway, unless the vessel meets the 2008 VGP graywater 

treatment standards.6 Vessels that do not travel more than 1 nm from shore must minimize the 

discharge of graywater and, provided the vessel has available graywater storage capacity, must 

dispose of graywater on shore if appropriate facilities are available,

7 unless the vessel can meet 

the 2008 VGP graywater treatment standards. Third, vessel operators must minimize the 

introduction of kitchen oils to the graywater system. When cleaning dishes, vessel 

owners/operators must remove as much food and oil residue as practicable before rinsing dishes. 

Vessel owners/operators should not add oils used in cooking to the graywater system or 

discharge oils from the galley and scullery in quantities that may be harmful as defined in 40 

CFR 110.8

Medium cruise ships (authorized to carry between 100 and 499 people for hire) and large 

cruise ships (authorized to carry 500 or more people for hire) with overnight accommodations 

have additional requirements for graywater discharges under the 2008 VGP. When pierside, 

medium and large cruise ships must discharge graywater to appropriate shore-side receiving 

facilities or treat graywater to meet discharge standards. When pierside, medium and large cruise 

ships traveling within 1 nm of shore must either store graywater in on-board holding tanks or 

treat graywater to meet the discharge standards. Untreated graywater can be discharged by 

medium and large cruise ships between 1 and 3 nm from shore if the vessel is traveling at 6 knots 

or greater (USEPA, 2008a).

In addition, soaps and detergents used in any capacity that will be discharged as part 

of graywater must be nontoxic and phosphate-free, and should be biodegradable where possible. 

Additional management practices are also applicable if the vessel is within nutrient-impaired or 

protected waters of the United States.

Large ferries that are authorized by the Coast Guard to carry 250 or more people are also

subject to additional graywater discharge requirements in the 2008 VGP; however, there are no 

numeric treatment standards. While pierside, large ferries must discharge graywater to shore-side 

reception facilities, if reasonably available. If shore-side reception facilities are not reasonably 

 5 2008.33 U.S.C.§§ 1342(r) and 1362(6)(A). 6 Discharge standards for graywater are 20 CFU/100 mls (30-day geometric mean) for fecal coliform bacteria, 10 

ug/L for total residual chlorine, and the secondary treatment standards for BOD5, suspended solids, and pH as 

defined in 40 CFR 133.102.

7 Appropriate reception facilities are those authorized for use by the port authority or municipality, and that treat the 

discharge in accordance with the reception facility’s NPDES permit. USEPA, Vessel General Permit for Discharges 

Incidental to the Normal Operation of Vessels (VGP). 8 40 CFR 110.3 defines oils that may be harmful as those which violate applicable water quality standards, or cause 

a film, or sheen, or discoloration of the surface of the water or adjoining shorelines, or cause a sludge or emulsion to 

be deposited beneath the surface of the water or upon adjoining shorelines.
Graywater Discharges from Vessels Section 1 - Introduction

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available, the large ferry must hold the graywater if the vessel has the holding capacity and 

discharge the effluent while underway outside 3 nm. If the large ferry operates within 3 nm of

shore, the ferry must discharge graywater while sailing at a speed of at least 6 knots, if feasible.

Both medium and large cruise ships and large ferries are also required to maintain records 

estimating all discharges of untreated graywater, including date, location and volume discharged, 

and speed of the vessel at the time of discharge in their recordkeeping documentation. These 

records can be maintained as part of the vessels sewage and graywater discharge record book 

required under 33 CFR 159.315.

EPA estimates that approximately 70,000 vessels are subject to the VGP (USEPA, 2011); 

however, not all of these vessels generate graywater. The vast majority (78 percent) of these 

vessels that are subject to the VGP operate primarily in the Mississippi River System and the 

Gulf Intracoastal Waterway. Twenty-one percent operate along the Atlantic, Pacific, and Gulf 

Coasts, and just over 1 percent mainly ply the waters of the Great Lakes. 

According to the U.S. Coast Guard’s Marine Information for Safety and Law 

Enforcement (MISLE) database, there are approximately 70,000 additional U.S.-flagged 

commercial fishing vessels that may generate graywater (USEPA, 2010). However, these 

vessels currently fall under the moratorium that exempts all commercial fishing vessels from the 

2008 VGP’s requirements for discharges incidental to the normal operation of a vessel, including 

graywater. 

After excluding barges (which generally do not generate graywater), EPA estimates there 

are between 43,000 and 50,000 vessels that may be subject to graywater discharge limitations 

under the next VGP. EPA reports there are between 43,000 and 45,000 vessels9

Pursuant to section 312 of the CWA, certain vessels operating in the Great Lakes are 

required to treat graywater discharges differently than other vessels operating on other waters of 

the United States. With respect to “commercial vessels” (as defined at 33 U.S.C. § 1322(a)(1)) 

operating on the Great Lakes, graywater is included in the definition of sewage (33 U.S.C. § 

1322(a)(6)), and thus subject to CWA § 312, not NPDES. On the Great Lakes, discharges of 

untreated graywater from commercial vessels are prohibited unless treated by a United States 

Coast Guard (USCG)-certified marine sanitation device (MSD).

associated with 

the current 2008 VGP whose Notice of Intent (NOI) status is either active or certified (i.e., in the 

waiting period prior to becoming active) (Albert, 2010).

10

Certain vessels operating in Alaska have federal requirements for graywater discharges, 

beyond those provided in the 2008 VGP. On December 12, 2000, Congress enacted an omnibus 

appropriation that included new statutory requirements for certain cruise ship discharges 

Commercial vessels operating 

on the Great Lakes can instead place both graywater and sewage into holding tanks and 

discharge the wastewater to shore-side facilities if the vessel is not equipped with an MSD. 

 9 Owner/operators only had to submit an NOI for a vessel if that vessel was greater than 300 gross tons or had the 

ability to carry 8 cubic meters of ballast water. Hence, there are some vessels larger than 79 feet, but smaller than 

300 gross tons, which are covered by the VGP, but did not have to submit an NOI.

10 For purposes of the CWA, a marine sanitation device is “any equipment for installation on board a vessel which is 

designed to receive, retain, treat, or discharge sewage, and any process to treat such sewage” (33 CFR 159.3).
Graywater Discharges from Vessels Section 1 - Introduction

5

occurring in Alaska (Departments of Labor, Health and Human Services, and Education, and

Related Agencies Appropriations Act, 2001, Pub. L. No. 106-554, 114 Stat. 2763 enacting into 

law Title XIV of Division B of H.R. 5666, 114 Stat. 2763A-315, and codified at 33 U.S.C. § 

1901 Note) (USEPA, 2008b). Title XIV sets discharge standards for sewage and graywater from 

certain cruise ships (those authorized to carry 500 or more passengers for hire) while operating in 

the Alexander Archipelago, the navigable waters of the United States in the state of Alaska, and 

within the Kachemak Bay National Estuarine Research Reserve.11

Based on the various regulations and permit requirements described above, only medium 

and large cruise ships, large ferries, and commercial vessels operating on the Great Lakes have 

specific discharge standards and/or treatment requirements mandating the use of a treatment 

technology for graywater under certain discharge conditions (e.g., large and medium cruise ships 

discharging graywater while at the pier, large cruise ships discharging graywater in Alaskan 

waters, commercial vessels discharging graywater in the Great Lakes, etc.). Requirements to 

hold graywater for discharge are also limited to a few specific conditions (e.g., for certain ocean 

going vessels) by the 2008 VGP. The remainder of this document describes the feasibility of 

expanding these requirements to apply to a greater number of vessels in U.S. waters or to 

broaden the discharge conditions under which they apply.

 11 Title XIV: Certain Vessels Operating in Alaska, 33 CFR 159, Part E.
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

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SECTION 2

GRAYWATER CHARACTERISTICS 

Graywater consists of discharges from galley, bath, and shower water, as well as 

wastewater from lavatory sinks, laundry, and water fountains (USEPA, 2008a). The volume of 

graywater generated depends largely on the type of vessel and the number of passengers 

onboard. For example, cruise ships generate more graywater than cargo ships since they have 

many more passengers and crew than other ships. Cruise ships also generate higher graywater 

volumes per capita because passengers on these vessels use galleys and accommodations (sinks 

and showers) to a greater extent than crew on cargo ships.12

Estimated graywater generation rates reported in response to EPA’s 2004 cruise ship 

survey ranged from 36 to 119 gallons/day/person, with an average of 67 gallons/day/person

(USEPA, 2008b) for large cruise ships. During EPA’s 2004 Alaskan cruise ship sampling 

program, graywater generation was measured on one ship at 45 gallons/day/person (USEPA, 

2006a). The 2004 cruise ship survey data indicate there is no relationship between per capita 

graywater generation rates and number of persons onboard the cruise ship. Estimated graywater 

generation rates reported in response to EPA’s 2004 cruise ship survey indicate that 

approximately 52 percent of graywater was from accommodations, 17 percent from laundries, 

and 31 percent from galleys. Total BOD5 contributions associated with all graywater sources 

shows that 52 percent is from galleys, 38 percent from food pulper/food waste, 8 percent from 

accommodations, and 2 percent from laundry (EcoMarine, 2010).

To validate the information gathered from EPA’s 2004 cruise ship survey, EPA reviewed 

literature information on graywater generation from other cruise vessels. According to a report 

from the Baltic Marine Environment Protection Commission, cruise ship graywater generation is 

approximately 120 liters per person/day (32 gallons/day/person) (Hanninen, 2009). The Ocean

Conservancy has estimated cruise ship grey water generation ranging from 114 to 322 liters per 

day (30 to 85 gallons/day/person) (Hanninen, 2009).

To determine the total annual volume of graywater generated by various classes of 

vessels, EPA used information collected from telephone calls with vessel operators together with 

typical passenger/crew numbers and graywater generation rates. Table 2 shows the total 

estimated graywater generation by various common vessel classes in U.S. waters. 

 12 Passengers and crew on cruise ships are expected to generate more graywater per capita than the crew of a cargo 

ships since persons on cruise ships are engaged in leisure activities and more likely to use larger quantities of water 

for bathing, food preparation, etc. 
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

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Table 2. Estimated Annual Graywater Generation by Commercial Vessels Greater Than 79 

Feet in Length in U.S. Waters

Vessel Class

Number 

of 

Vessels 

Average 

Number of 

Passengers 

and Crew

Number of 

Days Vessel is 

Generating 

Graywater in 

U.S. Waters 

(days/yr)a

Graywater 

Generation Rate 

(gal/day/person)

Total Annual 

Graywater 

Generation In 

U.S. Waters 

(gallons/yr)

Large Cruise Ships 47 3,506 b 85 c 45 d 630,291,000 e

Medium and Small 

Cruise Ships 36 187 f 274 g 45 h 83,006,000 e

Passenger Ferries

with Overnight 

Accommodations 6 610 i 274 i 45 h 45,128,000 e

Passenger Vessels 

Without Overnight 

Accommodations 106 282 j 274 k 45 h 368,568,000 e

Dry Cargo/Tanker 

Ships 970 25 l 60 m 14 n o to 45

20,370,000 to 

65,475,000 e

Great Lakes 

Freighters 52 24 p 136 p 45 h 7,638,000 e

Off-Shore Utility 

Vessels 1,964 4 q 31 r 45 h 10,959,000 e

Public Vessels, 

Unclassified 559 4 s 88 r 45 h 8,855,000 e

Tug Boats/Push 

Boats 5,424 6 t 350 u 12 v w to 45

136,685,000 to 

512,568,000 e

Fishing Vessels 69,944 z 7 x 94 y 45 h 2,071,000,000 e

a. Within 3 nm of shore or anywhere in the Great Lakes.

b. (CLIA, 2010)

c. Average passenger and crew numbers calculated from Friends of the Earth (FOE) Report Card for Cruise Ships entering U.S. 

Waters (FOE, 2010). 

d. Based on 31 cruise ships in Alaska from May-September in U.S. waters 60% of the time and 17 additional cruise ships 

outside Alaska within U.S. waters 2 days per week and 52 weeks per year. 

e. Sampling Episode Report for Holland America Veendam (Sampling Episode 6503). Washington, DC (USEPA. 2006a).

f. Total number of small and medium cruise ships from EPA 2008 VGP Notice of Intent Application database.

g. Average crew and passengers calculated from 23 medium and small cruise ships.

h. (USEPA, 2006b)

i. Passenger ferries having overnight accommodations. Includes five Alaska Marine Highway ferries and one Great Lakes ferry 

having overnight accommodations. 

j. Calculated based on a total of 7,833 inspected passengers vessels, of which 9 percent are greater than 79 feet (USEPA, 

2010b). Based on personal contact with the Passenger Vessel Association, approximately 15% of passenger vessels greater 

than 79 feet in length (106 vessels) discharge and the remainder use holding tanks and discharge to shore-side facilities.

k. Average number of passengers and crew calculated based on random sampling of data from tour boats, dinner cruise vessels, 

wedding party boats, whale watching tours, and shuttle service vessels.

l. (US Army Corp of Engineers, 2009)

m. (Chamber of Shipping of America, 2010)

n. Estimated time container vessels are in U.S. water based on USEPA Region 9 analysis of USCG Marine Information for 

Safety and Law Enforcement (MISLE) data that indicates 2.3 days per port call. EPA assumed vessel is in port 2.3 days 

every 2 weeks, which equals 60 days/yr.

o. Calculated based on vessels using only galley operations while in port per personal communication with Horizon Lines (See 

Attachment B)

p. Total number of members is 55; however, two have holding tanks and discharge shore-side and a third vessel is the car ferry 

Badger that discharges shore-side (Lake Carriers Association, 2010). 
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

8

q. Off-shore utility vessels include school ships, research vessels, supply vessels, industrial vessels, and mobile off-shore

drilling units. Of the 5,610 utility vessels not classified as tugs and tows, 35% are greater than 79 feet in length (USEPA, 

2010b)

r. Assumes off-shore utility vessels and public vessels have approximately four crew based on information in Great Lakes

Fisheries Commission (Schneider, 2001).

s. Of the 622 public vessels, unclassified, 90% are estimated to be greater than 79 feet in length (USEPA, 2010b).

t. (US Army Corp of Engineers, 2009).

u. Based on personal contact with AEP River Operations (see Attachment B).

v. Assumes vessel is out of service for 15 days per calendar year for maintenance per personal contact with AEP River 

Operations (See Attachment B)

w. Based on personal contact with AEP River Operations, who indicated the majority of tug boats are “day-boats” and therefore 

crew are not living onboard (See Attachment B).

x. Total number of commercial fishing vessels (USEPA, 2010b).

y. Commercial fishing vessels typically include a captain, first mate, engineer, boatswain, and three deck hands according to the 

Bureau of Labor Statistics, Agriculture, Forestry and Fishing, 2010-2011 Edition. 

z. Includes commercial fishing vessels of any length.

As expected, the class of vessels currently covered by the 2008 VGP that generates the 

largest volume of graywater is large cruise ships. Large cruise ships generate the largest volume 

of graywater due primarily to the large number of passengers and crew on these types of vessels. 

Medium and small cruise ships also generate relatively large volumes of graywater, also due to 

their relatively large number of passengers and crew. Surprising, however, is the relatively large 

volume of graywater generated by tug and push boats as compared to other types of vessels. 

Although the number of crew on tug and push boats is small in comparison to other vessels, there 

are a relatively large number of these vessels operating in U.S. waters (5,424), operating for a 

relatively large number of days, resulting in the generation of large volumes of graywater. 

Commercial fishing vessels, though currently excluded from NPDES permitting, may generate 

the highest total volume of graywater because of the large number of vessels in this class. 

In 2000, the Alaska Cruise Ship Initiative (ACSI) led a voluntary sampling effort to 

characterize graywater (discharged without treatment) and treated sewage discharges from cruise 

ships. Twice during the 2000 cruise season, samples were collected from each sewage and 

graywater discharge port from each of the 21 large cruise ships operating in Alaska. Sampling 

was scheduled randomly at various ports of call and on all major cruise routes in Alaska. 

Analytes included total suspended solids (TSS), BOD5, chemical oxygen demand (COD), pH, 

fecal coliform, total residual chlorine, free residual chlorine, and ammonia for all samples, and 

priority pollutants (metals, hydrocarbons, organochlorines) for one sample per ship. Voluntary 

sampling continued at the start of the 2001 cruise ship season through July 1, 2001, when Alaska 

state graywater and sewage discharge regulations (AS 46-03.460 - 46.03.490) came into effect. 

Table 3 shows the number of graywater and treated sewage discharge samples collected from 

cruise ships that fall into the different concentration ranges (treated sewage sample 

characteristics are shown to provide context for the pollutant strength of graywater). The results 

of this sampling effort demonstrate that the strength of the graywater, as indicated by TSS, 

BOD5, and COD, is variable, and that graywater can have high levels of fecal coliform bacteria

(ADEC, 2001).
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

9

Table 3. Percentage of Large Cruise Ship Untreated Graywater and Treated Sewage 

Samples by Concentration Range

Analyte and 

Wastewater Type Concentration Ranges

Fecal Coliform 

(MPN/100 mL) 0 to 200 200 – 1,000

1,000 –

1 million

1 million –

10 million >10 million

Percentage of Graywater 

Samples 

22% 3% 42% 19% 14%

Percentage of Treated 

Sewage Samples

40% 9% 23% 22% 6%

TSS (mg/L) 0 – 150 150 – 1,000 >1,000

Percentage of Graywater 

Samples

60% 35% 5%

Percentage of Treated 

Sewage Samples

22% 61% 17%

BOD5 (mg/L) 0 – 100 100 – 1,000 >1,000

Percentage of Graywater 

Samples

25% 55% 20%

Percentage of Treated 

Sewage Samples

51% 46% 3%

COD (mg/L) 0 – 100 100 – 1,000 1,000 – 10,000 >10,000

Percentage of Graywater 

Samples

2% 68% 26% 4%

Percentage of Treated 

Sewage Samples

0% 25% 62% 13%

Source: (ADEC, 2001)

In 2004, EPA sampled wastewater from four large cruise ships that operated in Alaska to 

characterize graywater and sewage generated onboard and to evaluate the performance of the 

Zenon, Hamworthy, Scanship, and ROCHEM advanced wastewater treatment systems (AWTS). 

EPA analyzed individual untreated graywater sources (accommodations, laundry, galley, and 

food pulper wastewater) on each ship for over 400 analytes, including pathogen indicators, 

suspended and dissolved solids, BOD5, oil and grease, dissolved and total metals, organics, and 

nutrients. In addition, laundry wastewater samples were analyzed for dioxins and furans, and 

galley wastewater samples were analyzed for organo-halide and organo-phosphorus pesticides. 

Table 4 summarizes the average conventional and nonconventional pollutant 

concentrations measured in combined untreated graywater. The data in Table 4 indicate that 

untreated graywater characteristics are similar to, and in some cases have a higher concentration 

of constituents than, domestic sewage entering land-based wastewater treatment plants. For 

example, the BOD5 of graywater measured by EPA in 2004 from large cruise ships (1,140 mg/L) 

is nearly four times higher than domestic sewage. The TSS concentration of graywater from 

cruise ships is nearly double the concentration expected from domestic sewage. The conclusion 

that that can be drawn from the pollutant concentration data in Table 4 is that graywater from 

commercial vessels has the potential to be as environmentally damaging to surface waters as 

untreated domestic sewage discharged in similar quantities. 
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

10

Table 4. Analyte Concentrations Measured in Untreated Graywater from Large Cruise 

Ships in Alaska and Armed Forces Vessels

Analyte Units

Average Untreated Graywater Concentrations

Large 

Cruise 

Ships (EPA 

2004 Data)a

Large Cruise 

Ships 

(ASCI/ADEC 

Data)b

Armed 

Forces 

Vesselsc

Domestic 

Sewaged

Alkalinity mg/L 53.8 57.8 NR NR

Ammonia Nitrogen mg/L as N 2.13 2.21 102 12 - 50

BOD5 mg/L 1,140 354 540 110 - 400

COD mg/L 1,890 1,000 1,440 200 - 780

Chloride mg/L 125 NC NR NR

Conductivity uS/cm 427 2,250 NR NR

Fecal Coliform 36,000,000 

CFU/100 mL

2,950,000 MPN/100 

mL

142,000 

CFU/100 mL

10,000-

100,000 

CFU/100 mLe

Hexane Extractable 

Material mg/L 149 78 164 f 50 - 150

Nitrate/Nitrite mg/L 0.087 0.009 3.2 NR

pH s.u. 6-9 6-9 NR NR

Settable Residue mg/L 25.6 1.1 NR NR

Silica Gel Treated Hexane 

Extractable Material mg/L 36.6 NC NR NR

Sulfate mg/L 49.9 NC NR NR

Temperature oC 39.6 NC NR NR

Total Dissolved Solids mg/L 578 NC 1,760 NR

Total Kjeldahl Nitrogen mg/L 26.2 11.1 140 NR

Total Organic Carbon mg/L 535 481 224 NR

Total Phosphorous mg/L 10.1 3.3 NR 4 - 8

Total Residual Chlorine ug/L NR 0.37 NR NR

TSS mg/L 704 318 802 120 - 360

Turbidity mg/L 224 NC NR NR

“NC” indicates that this information was not collected.

“NR” indicates that this information was not reported. 

a. EPA used flow rates for the individual graywater sources to calculate a flow-weighted average to represent untreated 

graywater. Graywater sources include accommodations, galley, laundry, and food pulper (USEPA, 2008b).

b.(ADEC, 2001), (USEPA, 2008b)

c. (USEPA, 1999)

d. (Qasim, 1999)

e. (Metcalf & Eddy, 1991)

f. Measured as oil and grease.

Table 5 presents the average concentration and the range of concentrations for all 

untreated graywater samples collected unannounced by ADEC between 2001 and 2010 for 13 

small cruise ships and five Alaska Marine Highway ferries as part of the Commercial Passenger 

vessel Environmental Compliance Program (CPVEC).

13

 13 Alaska Statute (AS) 46.03.460-46.03.490, Commercial Passenger Vessel Environmental Compliance Program 

(CPVEC).

Examination of ACSI/ADEC untreated 

graywater data from small passenger vessels, including small cruise ships and ferries having 

between 50 and 250 passengers, shows analyte levels similar to graywater from large cruise 

ships.
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

11

Table 5. Analyte Concentrations Measured in Untreated Graywater from Small Cruise 

Ships and Large Ferries in Alaska

Analyte

Average

Untreated 

Graywater 

Concentrationa

Range of 

Untreated 

Graywater 

Concentrationa

Domestic 

Sewageb

Ammonia Nitrogen (mg/L) 8.8 <0.05 to 403 12 - 50

BOD5 (mg/L) 326 <2 to 4,050 110 - 400

COD (mg/L) 592 <1.5 to 4,400 200 - 780

Fecal Coliform 608,000 (MPN/100 

ml)

<1 to 16,000,000 

(MPN/100 ml) c

10,000-100,000 

CFU/100 mL c d

Hexane Extractable Material (mg/L) 36 e <5.3 to 320 50 - 150

pH (s.u.) 7.5 4.6 to 10.9 Not Reported

Total Phosphorous (mg/L) 7.7 <0.017 to 69 4 – 8

Total Residual Chlorine (mg/L) 11.2 <0.02 to 270 Not Reported

TSS (mg/L) 122 <0.65 to 2,570 120 - 360

a. Alaska Commercial Passenger Vessel Environmental Compliance Program (CPVEC). Values reported as zero were not 

included in the statistical calculation; values reported as “ND” in the database was replaced with the reported method 

detection limit and a “<” symbol placed on the minimum value in the range. 

b. (Qasim, 1999)

c. Only fecal coliform values reported as MPN/100 ml were used in statistical calculations.

d. (Metcalf & Eddy, 1991)

e. Includes values measured as oil and grease.

In 2009, EPA collected untreated graywater characterization data from a variety of 

commercial fishing vessels and non-recreational and recreational vessels less than 79 feet in 

length (USEPA, 2010b). Specifically, EPA sampled graywater from eight vessels: five tugboats, 

a shrimper, a water taxi, and a recreational powerboat. These samples included graywater from 

sinks, dishwashers, and showers, as well as graywater samples from several mixed or unspecified 

sources. Graywater samples were analyzed for a range of analytes including pathogen indicators, 

classical pollutants, nonylphenols, metals, and nutrients. 

Table 6 shows the average graywater analyte untreated graywater concentration and 

range of untreated graywater concentration data from this sampling program. The graywater data 

collected by EPA from these vessels is similar to that collected by ADEC from small passenger 

vessels (see Table 5 above). For example, the average BOD5 concentration measured in 

graywater by ADEC from 2001 to 2010 was 326 mg/L, and the average BOD5 concentration in 

graywater measured by EPA in 2009 was 430 mg/L. 
Graywater Discharges from Vessels Section 2 - Graywater Characteristics

12

Table 6. Analyte Concentrations Measured in Untreated Graywater from Fishing 

Vessels, Non-Recreational and Recreational Vessels Less Than 79 Feet in Length

Analyte

Average Untreated 

Graywater 

Concentrationa

Range of Untreated 

Graywater 

Concentrationa

Domestic 

Sewageb

Ammonia Nitrogen (mg/L as N) 1.3 0.19-4.5 12 - 50

BOD5 (mg/L) 430 99-1,200 110 - 400

COD (mg/L) 1,000 180-4,000 200 - 780

Fecal Coliform (CFU/100 ml) 200,000 Nondetect-570,000

10,000-

100,000c

Total Phosphorous (mg/L) 1.4 0.42-3.4 4 – 8

Total Residual Chlorine (mg/L) 0.12 Nondetect-0.11 Not Reported

TSS (mg/L) 52 14-81 120 - 360

Note: Nondetect concentrations were replaced with 1⁄2 of the reporting limit for calculating average concentrations, which 

 can result in the average concentration being higher than the upper range.

a. USEPA Report to Congress: Study of Discharges Incidental to Normal Operation of Commercial Fishing Vessels and 

Other Non-Recreational Vessels Less Than 79 Feet. Average concentration based on eight vessels sampled by EPA. 

b. (Qasim, 1999)

c. (Metcalf & Eddy, 1991)

The analyte concentrations shown in Table 6 above reflect the washing and bathing activities that 

generate graywater onboard these vessels. EPA found that BOD5, oil and grease, (measured as 

hexane extractable material) and TSS all exceeded a Potential Hazard Quotient (PHQ)14

 14 PHQ divides the vessel’s average concentration by a corresponding screening benchmark. For BOD5 and oil and 

grease, the screening benchmark is the secondary treatment standards included in 40 CFR 133. 

threshold of 1, indicating that these pollutants in untreated graywater may have the potential to 

negatively impact receiving waters. 
Graywater Discharges from Vessels Section 3- Current Graywater Management Practices

13

SECTION 3

CURRENT GRAYWATER MANAGEMENT PRACTICES

Graywater management strategies differ depending on regulatory regime, vessel type, 

size, and where the vessel discharge occurs. The following discussion provides the current 

graywater management strategies for vessels that have specific discharge requirements. 

3.1 GRAYWATER MANAGEMENT FOR LARGE CRUISE SHIPS

Large cruise ships (authorized to carry 500 or more persons) that are pierside must either 

discharge to appropriate reception facilities, hold graywater and discharge when the vessel is 

underway, or treat graywater with a device to meet discharge standards.15

Large cruise ships that operate in Alaskan waters must either treat their commingled 

sewage and graywater using AWTS

Large cruise ships 

operating within 1 nm of shore must either hold graywater or treat graywater to meet the 

discharge standards. Large cruise ships operating between 1 nm and 3 nm from shore must either 

meet the discharge standards or discharge while the cruise ship is sailing at a speed of at least 6 

knots. 

16

3.2 GRAYWATER MANAGEMENT FOR MEDIUM CRUISE SHIPS AND LARGE FERRIES

to achieve the required discharge standards, or hold their 

wastewater for discharge outside Alaskan waters. AWTS generally provide improved screening, 

biological treatment, solids separation (using filtration or flotation), and disinfection (using 

ultraviolet light) as compared to traditional Type II MSDs that use either simple maceration and 

chlorination, or biological treatment with gravity settling, followed by chlorine disinfection.

Under the VGP, medium cruise ships (authorized to carry 100 to 499 people for hire) 

must use appropriate reception facilities for graywater while pierside, unless the vessel treats 

graywater with a device that will achieve the discharge standards. If appropriate reception

facilities are not available and the vessel cannot treat graywater to the discharge standard, then 

the vessel must hold graywater and discharge while the vessel is underway and outside 1 nautical 

mile from shore. Large ferries17

 15 Discharge standards for graywater from large cruise ships (ships authorized to carry 500 or more persons) must 

meet secondary treatment standards for BOD5, oil and grease, and pH as defined in 40 CFR 133.102. Concentrations 

of total residual chlorine may not exceed 10 ug/L and fecal coliform bacteria may not exceed 20/100 ml (geometric 

mean) during any 30-day period. USEPA, Vessel General Permit for Discharges Incidental to the Normal Operation 

of Vessels (VGP). Version November 2010.

must use appropriate reception facilities for graywater when 

16 Note that one of these AWTS, the Rochem system, treats low-concentration graywater (laundry and 

accommodations) separately from high-concentration wastewater (sewage and galley) using different processes 

(USEPA, 2006c). Specifically, low-concentration graywater is screened to remove fibers and hair, processed 

through reverse osmosis membranes to remove particulates and dissolved solids, and disinfected using ultraviolet 

light to reduce pathogens. However, because the reverse osmosis membranes generate a reject “concentrate” stream 

that requires further treatment (treated by the high concentration wastewater treatment process), graywater treatment 

is not completely independent of sewage treatment. 17 With regard to graywater management, a “Large Ferry” means a ferry that is authorized by the Coast Guard to 

carry 250 or more people. USEPA, Vessel General Permit for Discharges Incidental to the Normal Operation of 

Vessels (VGP). Version November 2010. 
Graywater Discharges from Vessels Section 3 - Current Graywater Management Practices

14

pierside, or hold the graywater if the vessel has the holding capacity and discharge the effluent 

while the vessel is underway and sailing at a speed of at least 6 knots, if feasible.

3.3 GRAYWATER MANAGEMENT FOR COMMERCIAL VESSELS ON THE GREAT LAKES

Under CWA section 312, graywater discharges generated onboard commercial vessels 

operating on the Great Lakes must be treated through an MSD prior to discharge, or be held in 

on-board storage tanks and discharged to shore-side facilities.

3.4 GRAYWATER MANAGEMENT FOR OTHER VESSELS

Personal contact with operators of small cruise ships, ocean-going cargo ships, and tug 

and tow boats shows that graywater is being managed on these vessels as well. Attachment B

contains summaries of information collected during these telephone contacts. Table 7 lists the 

vessel classes contacted and summarizes the information gathered. 

According to one small cruise line operating from Maine to Florida, vessels store 

graywater in onboard tanks if the vessels are located within a no-discharge zone (NDZ) and then 

discharge the graywater once they are outside the NDZ. This cruise line also pumps graywater 

shore-side when receiving facilities are available. According to the contact at the cruise line 

company, shore-side receiving facilities are available at some of the larger ports of call (e.g., 

Bangor, Maine), while others can truck collected graywater to shore-side receiving facilities 

(e.g., Troy, New York). The contact stated that many of the small ports their cruise ships enter 

have shore-side receiving facilities for small vessels such as yachts, but these dock areas are too 

small for their cruise ships. Therefore, they are forced to dock in locations where shore-side 

receiving facilities are not available. Conversely, other shore-side receiving facilities are located 

near docks only accessible by much larger vessels. 

Two tugboat operators were contacted to determine how graywater is managed on these 

vessels. Tugboats operated by one operator on the Mississippi River generate accommodations, 

galley, and laundry wastewaters that are disinfected by routing the graywater through the 

disinfection portion of the vessels’ Type II MSD. Each of this operator’s tugs has been fitted 

with Owens KleenTank Type II MSDs for sewage treatment (biological treatment followed by 

chlorine tablet disinfection). This operator selected this graywater management practice for their 

22 tugboats in anticipation of upcoming rules regarding graywater discharges. According to the 

operator, their tugboats were constructed in 2007 and included piping graywater through 

disinfection as a design requirement. Older tugs, such as those operated by a major tugboat 

operator in the Baltimore, Maryland and Chesapeake Bay region, discharge graywater overboard 

without treatment. These tugs do not include graywater piping that would allow the operators to 

collect and treat graywater prior to discharge. Graywater from this operator’s tugs also includes 

wastewater from accommodations, galley (including dishwashers), and laundry. 

Graywater management information was also gathered from personal contact with two

container ship companies. According to one of these companies, graywater is generated by 

approximately 26 crew members in the galley, laundry, and accommodations, and is discharged 

overboard without treatment. The operator explained their vessels have limited holding capacity 

for graywater to allow for off-shore discharge (i.e., >3 nm), and most have not piped their sinks, 
Graywater Discharges from Vessels Section 3 - Current Graywater Management Practices

15

showers, laundry, and galley to existing holding tanks. Graywater generation while in port is 

typically limited to galley water because container ships are only in port for approximately 12 

hours to load and unload cargo.

Based on personal communication with a shipping company, other activities that generate 

graywater such as laundry and accommodations are performed when the vessel is well beyond 3 

nm from shore.

Another shipping company’s container ships can be in port for as long as seven days, 

which requires their vessels to store graywater in their after-peak ballast tank. According to the 

contact, their container vessels generate approximately 10 m3

/day (2,640 gal/day) of graywater 

from the galley, showers and sinks, and laundry, plus another 3 to 4 m3/day of treated sewage 

while the vessels are in U.S. waters. According to the representative, storage of graywater in 

ballast tanks is not ideal because the tanks cannot be easily cleaned and there is a potential for 

hydrogen sulfide buildup that can be a serious health and safety risk when crew members need to 

enter the tanks. In addition, based on personal contact with the shipping company, storing 

graywater in ballast tanks while in port can limit vessel stability considering the amount of cargo 

that can be loaded.
Graywater Discharges from Vessels Section 3 - Current Graywater Management Practices

16

Table 7. Vessel Operators Contacted to Discuss Graywater Management Practices

Vessel 

Operator Vessel Class

Vessel Location 

and/or Port

Number of 

Vessels in 

Fleet

Typical Number of 

Persons Onboard 

(Passengers and Crew)

Graywater 

Management

Sewage 

Management

Vessel 

Operator 1

Fleet Boats 

and Tug Boats

Mississippi River 22 6 to 9 Chlorination prior to 

discharge

Biological, gravity settling, 

chlorine tablet disinfection 

(Owens KleenTank)

Vessel 

Operator 2

Small Cruise 

Ships

Northeast, 

Mid-Atlantic 

Coast,

Columbia River

5 123 Direct discharge 

without treatment 

unless in NDZs

Maceration and chlorination

Vessel 

Operator 3

Container 

Ships

New York,

Alaska,

Hawaii,

Florida,

Puerto Rico

21 26 Direct discharge 

without treatment

Maceration and chlorination

Vessel 

Operator 4

Container 

Ships

Gulf Coast, MidAtlantic, Pacific 

Northwest

40 22 Hold in after-peak 

ballast tank

Maceration and Chlorination

Vessel 

Operator 5

Tug Boats and

Articulated 

Tug/Barge 

Boats

Baltimore Area 

and Atlantic Coast

40 5 to 11 Direct discharge 

without treatment 

unless in NDZs

Maceration and chlorination

Vessel 

Operator 6

Medium Size 

Cruise Ships

Alaska and 

Caribbean

1 740 Treated through AWTS Biological with membrane 

filtration and UV disinfection

AWTS: Advanced wastewater treatment system.
Graywater Discharges from Vessels Section 4- Graywater Control Strategies 

17

SECTION 4

GRAYWATER CONTROL STRATEGIES 

As indicated in the tables above, graywater can contain constituent levels similar to raw 

domestic sewage and therefore discharging graywater without treatment may have the same 

environmental impacts as discharging raw domestic sewage without treatment. However, unlike 

domestic sewage, graywater can be discharged without treatment into U.S. waters, with the 

exception of Alaska and the Great Lakes. To determine if vessel MSDs and sewage treatment 

plants (STPs)18

Table 8

are applicable for treating graywater combined with sewage from all types of 

vessels, EPA contacted several system vendors (see for the list of vendors contacted). 

Attachment B contains reports documenting information collected during these telephone 

contacts, and Attachment A includes published literature from a number of the vendor web sites. 

Specifically, discussions with the vendors were to determine the types of vessels that have or 

could later install treatment systems, the minimum number of passengers/crew required for the 

systems to operate properly, the types of wastewaters that could be treated, and the treatment 

system operation and maintenance requirements.

The treatment systems listed in Table 8 have received either a Certificate of Approval 

issued by the U.S. Coast Guard pursuant to CWA section 31219 or a Certificate of Type 

Approval issued by a certifying body pursuant to MARPOL Annex IV20 for the treatment of 

sewage only;

21

Table 9

in some cases, the treatment systems have received both a Certificate of Approval 

and a Certificate of Type Approval. Based on vendor claims, and in several cases supported by 

analytical monitoring data from large AWTS, some treatment systems can produce effluent with 

sufficient quality for continuous discharge in Alaskan waters (to meet Title XIV and 2008 VGP

requirements) or within 1 nm of the U.S. shore (to meet 2008 VGP limits). Although some 

vendors claim their systems have the capability to treat both sewage and comingled sewage and 

graywater, the MSD type-approval testing procedures performed in the laboratory do not use 

sewage comingled with vessel graywater. Instead, based on personal contact with an MSD 

testing laboratory, MSD type approval testing uses either domestic sewage, which consists of

both sewage and graywater, or sewage collected from “honey dipper” trucks, which may contain 

far less graywater, depending on the source (See Attachment B). lists MSD type 

approval standards and discharge standards for various U.S. and international regulations. 

Although all the vendors contacted can supply MSDs certified to either the CWA section 

312 standards or the MARPOL standards, many may not be achieving the type certification 

 18 STPs are certified to meet the MARPOL Annex IV effluent standards and performance tests adopted by the 

Marine Environment Protection Committee (MEPC) in either of the following resolutions: MEPC.2(VI) on 

December 3, 1976, or MEPC.159(55) on October 13, 2006.

19 See 33 U.S.C. § 1322(b); 40 CFR Part 140 (EPA performance standards) and 33 CFR Part 159 (U.S. Coast Guard 

MSD regulations).

20 See MARPOL Annex IV; Resolution MEPC. 159(55), Resolution MEPC.2(VI). 

21 On October 13, 2006, the IMO’s Marine Environment Protection Committee (MEPC) adopted revised effluent 

standards and performance tests for STPs. See resolution MEPC.159(55). The revised standards and testing 

requirements apply to STPs installed onboard ships on or after January 1, 2010. Ships with STPs installed prior to 

that date may continue to use equipment certified to the previous standards.
Graywater Discharges from Vessels Section 4- Graywater Control Strategies 

18

standard once installed on the vessel.

22 For example, the manufacturers of some treatment 

systems stated their systems are not equipped with any type of continuous effluent monitors, and 

CWA section 312 does not contain provisions requiring routine effluent sampling or monitoring 

to verify compliance with the standards once the units are installed onboard. The manufacturers 

also stated that their systems are not typically interfaced with the vessels’ control systems, so 

crew members would need to physically inspect all mechanical systems (e.g., pumps, blowers) to 

verify that they are actually operating. In addition, the MSDs having biological treatment use 

chlorine tablets for disinfection. Disinfection with tablets leads to a more widely varying level of 

residual chlorine than other disinfection methods. Therefore, the natural variability in 

wastewater characteristics would result in discharging fecal coliform bacteria or residual chorine 

above the Title XIV or IMO Resolution MEPC 159(55) standards. Poor effluent quality

produced by such systems has been documented in sampling data collected by ADEC.23

More data and information would be useful to determine the effectiveness of MSDs used 

for treatment of combined sewage and graywater. Additional data characterizing the quality of 

untreated graywater from a variety of vessel types would assist in better characterizing potential 

environmental impacts from this discharge. Data collection which would improve EPA’s 

understanding of graywater characteristics and its treatability include:

None of 

the vendors contacted by EPA claimed they required any graywater addition or other process 

water addition to operate their sewage treatment systems. However, based on EPA’s experience 

with MSDs, process water is commonly added to provide flushing water needed to move sewage 

through the vessels’ piping system, and/or to provide a source of chloride for the maceration and 

chlorination type MSDs. 

• Collecting effluent performance data for MSDs treating graywater or both sewage 

and graywater to determine whether the systems are actually performing to their 

original USCG type certification, 

• Collecting influent and effluent sampling data from AWTS that are operating on 

existing vessels with relatively small numbers of passengers/crew to verify system 

performance claims, and

• Gathering additional cost data to determine the economic impacts to vessel 

owners and operators if both sewage and graywater is treated to either USCG or 

IMO MEPC 159(55) standards. 

 22 Vendor MSD are typically the same as those installed on small ships that were sampled by ADEC. Sampling 

results show that these systems were not achieving their type certification standards (ADEC 2006, ADEC 2007). 23 Alaska Department of Environmental Conservation, Commercial Passenger Vessel Compliance Program 2001 to 

2010 Small Ship Wastewater Sampling Results (ADEC 2006, ADEC 2007). 
Graywater Discharges from Vessels Section 4 - Graywater Control Strategies

19

Table 8. Vessel Sewage Treatment System Vendors Contacted to Discuss Graywater Treatment Claims

Vendor

Treatment 

System Name

Treatment System

Description

Wastewaters 

Treated

System 

Certifications

Target 

Analytes

Vessel Classes 

Currently Using 

Treatment 

System

Minimum 

Number of 

Passengers and 

Crew Required 

for Operation

Vendor 1 EVAC 

Membrane 

Bioreactor 

Treatment Without 

Disinfection

Sewage,

Commingled 

Sewage and 

Gray Water, and 

Graywater Only

IMO Resolution 

MEPC 159(55)

BOD 

COD 

TSS 

Fecal 

Coliform

Naval Vessels

Oceanographic 

Vessels

Small Cruise Ships 25a

Vendor 2 Hamann AG

Biological 

Treatment with 

Dissolved Air 

Flotation and 

Ultraviolet (UV) 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD 

COD 

TSS 

Fecal 

Coliform

Mega-Yachts

Small Passenger 

Vessels 10

Vendor 3 FAST System

Fixed-Media 

Biological 

Treatment with 

Gravity 

Clarification and 

Chlorine 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD 

COD 

TSS 

Fecal 

Coliform

Tug Boats

Tow Boats

Off-shore 

Platforms

Crew Boats 10

Vendor 4

Hamworthy 

Super Trident

Biological 

Treatment with 

Gravity 

Clarification and 

Chlorine 

Disinfection and 

Dechlorination

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD 

COD 

TSS 

Fecal 

Coliform

Large Cruise Ships

Small Cruise Ships 21b

Vendor 5 CleanSea

Moving Bed 

Biological Reactor 

with Dissolved Air 

Flotation, Tertiary 

Filtration and UV 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and

CWA Section 312c

Ammonia 

BOD 

COD 

TSS 

Fecal 

Coliform

Large Cruise Ships

1,000
Graywater Discharges from Vessels Section 4 - Graywater Control Strategies

20

Table 8. Vessel Sewage Treatment System Vendors Contacted to Discuss Graywater Treatment Claims

Vendor

Treatment 

System Name

Treatment System

Description

Wastewaters 

Treated

System 

Certifications

Target 

Analytes

Vessel Classes 

Currently Using 

Treatment 

System

Minimum 

Number of 

Passengers and 

Crew Required 

for Operation

Vendor 6 KleenTank

Biological 

Treatment with 

Gravity 

Clarification and 

Chlorine Tablet 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and

CWA Section 312c

BOD5

COD 

TSS 

Fecal 

Coliform

Drilling Vessels 

Ferries

Lift Boats

Tow Boats

Tug Boats 

3

Vendor 7 Red Fox

Biological 

Treatment with 

Gravity 

Clarification and 

Chlorine Tablet 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD5

COD 

TSS 

Fecal 

Coliform

Ferries

Drilling Vessels

Pleasure Yachts

Small Cruise Ships

Tug Boats

Tow Boats 1

Vendor 8 Rochem

Membrane 

Bioreactor With 

UV Light 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD5

COD 

TSS 

Fecal

Coliform

Mega-Yachts

Large Cruise Ships

Small Cruise Ships

TBD

Vendor 9 Scanship

Biological 

Treatment with 

Dissolved Air 

Flotation and UV 

Disinfection

Sewage and

Commingled 

Sewage and 

Graywater

IMO Resolution 

MEPC 159(55) and 

CWA Section 312c

BOD5

COD 

TSS 

Fecal 

Coliform

Ferries

Large Cruise Ships

Off-Shore 

Platforms 100

TBD: To be determined.

a. Sewage only based on a vacuum collection system.

b. Sewage only based on gravity collection system.

c. 33 U.S.C. Section 1322(a)(6), a marine sanitation device includes “any equipment for installation on board a vessel which is designed to receive, retain, treat, or discharge 

sewage, and any process to treat such sewage.” Under CWA section 312, vessels equipped with installed toilet facilities are prohibited from operating on the navigable 

waters (which include the 3-mile territorial seas), unless the vessel is equipped with an operable MSD certified by the Coast Guard to meet applicable performance 

standards. 33 U.S.C. § 1322(h)(4); see also 40 CFR Part 140 (EPA MSD performance standards) and 33 CFR Part 159 (U.S. Coast Guard MSD regulations). 
Graywater Discharges from Vessels Section 4 - Graywater Control Strategies

21

Table 9. Vessel Sewage Standards under Various U.S. and International Regimes

Analyte

CWA Performance

Standards For Type

II MSDs(40 CFR 140; 

33 CFR 159)

IMO Resolution 

MEPC.2 (VI)

IMO Resolution 

MEPC 159(55)

Title XIV: 

Certain Vessels 

Operating in 

Alaska (33 

CFR 159, 

Subpart E)

BOD5 (mg/L) Geometric mean ≤ 50 Geometric mean

≤ 25

30

COD (mg/L) ≤ 125

Fecal Coliform

(CFU/100 ml)

≤ 200 per 100 mL Geometric mean ≤ 250 

per 100 mL (fecal 

coliform; most 

probable number)

Geometric mean ≤ 

100 per 100 mL a

20

Residual 

Chlorine 

(mg/L)

To the degree 

practicable

0.5 0.01

TSS (mg/L) ≤ 150 Geometric mean ≤ 50

(shore-side testing)

Geometric mean

≤ 35

30

pH (s.u.) 6 to 8.5 6 to 9

USCG: United States Coast Guard.

IMO: International Maritime Organization.

a. Thermotolerant coliforms.

To further document the performance of type-certified vessel sewage treatment systems, 

EPA compiled ADEC effluent sampling data from five Alaska Marine Highway vessels. Each 

vessel was fitted with a traditional Type II MSD that treats comingled sewage and graywater. 

Table 10 shows ADEC’s average treatment system effluent data collected between 2006 and 

2010. The data show that treatment system effluent TSS concentrations achieve the 33 CFR 159 

standards on four of the five vessels; however, only one vessel achieved the fecal coliform 

standard. Because maceration and chlorination systems can add up to 10 times the volume of 

process water compared to the amount of wastewater being treated (Griffiths, 2009), it is unclear 

whether the TSS results shown in Table 10 are from actual treatment or from dilution by process 

water. These data clearly show that, although traditional Type II MSDs and other similarly

designed and operated systems are type-certified, they may not be meeting the applicable 

standards once they are placed into service on vessels.
Graywater Discharges from Vessels Section 4 - Graywater Control Strategies

22

Table 10. Average Treated Effluent Data For Five Alaska Marine Highway Vessels 

Treating Comingled Sewage and Graywater

Vessel

Columbia Kennicott Malaspina Matanuska Taku

MSD Type Maceration/

Chlorinatin

Macerator/

Chlorination

Macerator/

Chlorination

Macerator/

Chlorinator

Maceration/

Chlorination

Manufacturer Omnipure Orca Omnipure Omnipure Effluent 

Technology

Total Passengers and Crew 691 804 550 548 412

Wastewaters Treated

Comingled 

Sewage and 

Graywater

Comingled 

Sewage and 

Graywater

Comingled Sewage and 

Graywater

Comingled 

Sewage and 

Graywater

Comingled 

Sewage and 

Graywater

Analyte Average Effluent Concentrationsa

Ammonia (mg/L) 27.3 0.7 17.0 13.2 6.2

BOD5 (mg/L) 124 19 179 129 105

COD (mg/L) 641 610 875 691 868

Fecal Coliform (CFU/100 

ml)b 249,000 70 1,344,000 889,000 67,500

Total Chlorine (mg/L) 5.5 4.4 6.2 6.8 4.7

TSS (mg/L) 95 28 80 100 180

a. ADEC Commercial Passenger Vessel Compliance Program 2006-2010. For values reported as either “ND” or zero in 

the database, the value was replaced with the reported method detection limit.

b. Only fecal coliform values reported as CFU/100 ml were used in statistical calculations.

EPA also contacted treatment vendors having systems that use a combination of 

treatment technologies such as filtration, biological treatment and/or disinfection (systems 

similar to those found on large cruise ships operating in Alaska).

24 As indicated in Table 11, 

these systems, found primarily on large cruise ships, achieve significant reductions in key 

analytes as compared to traditional Type II MSDs using similar technologies. For example, 

ADEC collected effluent data in 2006 and 2007 for two Alaska passenger vessels using Red Fox 

Type II MSDs (biological treatment, gravity setting, and chlorine disinfection) treating sewage

(ADEC, 2006 and 2007). The effluent data from these two vessels show BOD5 concentrations 

ranging between 171 and 273 mg/L, and TSS concentrations ranging between 120 and 603 mg/L. 

Comparing these effluent concentrations to the effluent concentrations shown in Table 11 clearly 

shows that the AWTS provide superior performance. 

 24 AWTS approved for continuous discharge in Alaska waters have been documented in the literature to achieve the 

effluent discharge standards for BOD5, TSS, fecal coliform, residual chlorine, and pH specified at 33 CFR 159, 

Subpart E. See Alaska Department of Environmental Conservation, Commercial Passenger Vessel Compliance 

Program 2006 Large Ship Wastewater Sampling Results.
Graywater Discharges from Vessels Section 4 - Graywater Control Strategies

23

Table 11. Large Cruise Ships AWTS Influent and Effluent Concentrations and Percent 

Removals

Analyte

Average Large Cruise 

Ship AWTS Influent

Concentrationa

Average Large Cruise 

Ship AWTS Effluent

Concentrationb

Overall AWTS

Percent Removala

Ammonia (mg/L as N) 78.6 36.6 58 to 74

BOD5 (mg/L) 526 7.99 >99

COD (mg/L) 1,140 69.4 >93 to 97

Fecal Coliform (CFU/100 

ml)

103,000,000 14.5 >99

Oil and Greasec (mg/L) 95.6 5.74 >91 to >96

Total Chlorine (mg/L) NA 0.34 NC

Total Phosphorous (mg/L) 18.1 5.05 41 to 98

TSS (mg/L) 545 4.5 >99

Source: (USEPA, 2008b)

The “>” symbol indicates a minimum level of removal.

NA: Data not available.

NC: Not calculated.

a. Based on data collected by EPA in 2004 and 2005.

b. Based on data collected by ADEC/USCG 2003 to 2005; data collected by EPA in 2004 and 2005; and data collected 

through EPA’s 2004 cruise ship survey.

c. Oil and Grease measured as Hexane Extractable Material (HEM).

Although some vendors stated their AWTS were too large to place on small cruise ships 

and passenger ferries, other vendors do provide units that could handle smaller passenger 

numbers such as mega-yachts. For example, through personal communication with two 

manufacturers, both claim that their systems can be installed on small vessels. In addition, one 

vendor claims their system can treat sewage, commingled sewage and graywater, or graywater 

only. This was the only vendor contacted that claimed their system could treat graywater only; 

however, they qualified that one of the graywater sources must be from the vessel galley to 

provide sufficient BOD5 for biological treatment (All other AWTS vendors stated that some

sewage was required to provide sufficient BOD5 for biological treatment). According to the 

vendor, their system can be installed on vessels with as few as 25 crew/passengers. The system 

has been installed on a U.S. Navy oceanographic vessel; however, this vendor did not provide 

the number of crew or the name of the vessel. 

Another vendor, has a biological treatment system with dissolved air floatation for solids 

separation that can be installed on vessels having as few as 100 passengers and crew. The 

Scanship system can treat commingled sewage and graywater, including wastewater from the 

food pulper system. According to the vendor, the company is also currently testing a nitrification 

and denitrification unit that has been integrated into its existing treatment system on the 

Norwegian Star, a large cruise ship that operates in Alaska. The system on the Norwegian Star is 

currently being tested on voyages between Los Angeles and Mexico’s Baja peninsula in order to 

have the system ready for the 2011 Alaska cruise season. The vendor has also stated it is 

considering retrofitting the nitrification and denitrification unit on all its existing treatment 

systems and any new cruise ship installations.
Graywater Discharges from Vessels Section 5 - Summary

24

SECTION 5

SUMMARY

Graywater from vessels contains analytes with concentrations similar to those in raw 

domestic sewage. Under CWA section 312, only commercial vessels on the Great Lakes are 

required to consider graywater as sewage and therefore treat graywater through an MSD prior to 

discharge. In Alaska, Title XIV and Alaska state law require that medium and large cruise ships 

either hold sewage and graywater for discharge outside Alaska waters, or treat graywater and 

sewage to EPA’s CWA section 312 performance standards for Type II MSDs when between 1 

and 3 nm from shore. Medium and large cruise ships within 1 nm of shore must treat sewage 

and graywater to meet stringent standards for fecal coliforms and total chlorine, and meet 

secondary treatment standards for BOD5, TSS and pH (found at 40 CFR 133.102).

Alaska statute (AS) 46.03.462(e), administered by ADEC as part of the CPVEC, allows 

small passenger vessels25

Although processing graywater commingled with sewage through a system that has been 

type-certified to meet either the CWA section 312 performance standards or the IMO Resolution 

MEPC 159(55) standards appears to be a viable option, there are concerns regarding the ongoing 

performance of the systems once in service. Data collected by ADEC for Alaska Marine 

Highway ferries that treat combined sewage and graywater indicates that traditional treatment 

system designs (e.g., maceration and chlorination) are often not meeting the applicable vessel 

in Alaska to discharge graywater without treatment as long as the 

vessel has developed and implemented an approved Best Management Practice Plan. The 2008 

VGP requires that all medium and large cruise ships in U.S. waters treat graywater if discharged 

within 1 nm of shore, or hold and discharge graywater outside 1 nm when the vessel is traveling 

at 6 knots. Under the 2008 VGP, commercial vessels outside of the Great Lakes and Alaska can 

discharge graywater without treatment with some notable restrictions. With the exception of 

large and most medium size cruise ships, and some large container/tank ships, many commercial 

vessels face challenges containing near-shore graywater discharges. The reasons why such 

vessels must discharge within 3 nm include: 1) insufficient capacity to hold graywater, 2) piping 

systems that discharge graywater overboard immediately upon generation, and 3) vessel 

operations exclusively within 3 nm of shore, thus providing no opportunity to discharge outside 

3 nm. For example, graywater generated onboard a cargo/container ship is typically piped 

directly overboard, even though the average sewage storage capacity for these vessels is nearly 8 

days (Chamber of Shipping of America, 2010). Based on personal communication with a cruise 

line company, small cruise ships typically have some capacity to store graywater while operating 

in NDZs, but these vessels spend the majority of their time operating within 3 nm of shore (See 

Attachment B). Most tugboats discharge graywater directly overboard without treatment and 

operate almost exclusively within 3 nm of shore. Large cruise ships, however, do have the 

capacity to hold graywater for 1 to 2 days as evidenced by their ability to hold all wastewaters 

while sailing in areas such as Glacier Bay in Southeast Alaska, where discharges are generally 

prohibited under their concession contracts with the National Park Service. Large cruise ships 

also periodically operate away from shore, providing opportunity to discharge stored graywater 

outside U.S. waters.

 25 A small vessel has 50-249 overnight passengers as defined in AS 46.03.490(7).
Graywater Discharges from Vessels Section 5 - Summary

25

sewage standards. In fact, because sampling of effluent from type-certified treatment systems is 

not required outside of Alaska, ongoing performance data from vessels operating in other areas 

of the country are not available.

Discussions with vendors of AWTS approved for large cruise ships that continuously 

discharge in Alaskan waters found that some have developed units that can be installed on 

vessels having as few as 25 persons. Specifically, this vendor has developed a membrane 

bioreactor that can treat not only sewage and commingled sewage and graywater, but also 

graywater only (provided graywater includes galley wastewater). Another vendor has a 

biological treatment system with dissolved air flotation and UV disinfection that can be used on 

mega-yachts with as few as 10 persons. Unfortunately, no “real-world” data exists on the actual 

shipboard performance for these systems.

Other vendors that claim their devices can achieve IMO Resolution MEPC 159(55) 

discharge standards are relying only on their initial type certification data to support their claims. 

None of these systems is equipped with continuous monitoring equipment (e.g., for turbidity), 

disinfection is performed with simple chlorine tablets, no operating and maintenance labor is 

required, and the only available ongoing performance data from Alaska shows poor effluent 

quality from these devices. In addition, these vendors do not follow up with performance 

sampling of installed units, because any sampling is at the discretion of the vessel operator.
Graywater Discharges from Vessels Section 6 - References

26

SECTION 6

REFERENCES

ADEC. (2001). Alaska Cruise Ship Initiative Part 2 Report. Juneau, AK.. 

ADEC. (2006). Commercial Passenger Vessel Compliance Program 2006 Small Ship 

Wastewater Sampling Results.

ADEC. (2007). Commercial Passenger Vessel Compliance Program 2007 Small Ship 

Wastewater Sampling Results.

Albert, R. (2010). Development of the Next VGP – Stakeholder Listening Session, Washington 

DC. December 15, 2010.

Chamber of Shipping of America. (2010). Comments and Supplemental Data on Petition to 

Revise the Performance Standards for Type II Marine Sanitation Devices (Document 

Number EPA-HQ-OW-2010-0126-0042.1).

Cruise Line Industry Association (CLIA). (2010). Comments on Petition to Revise the 

Performance Standards for Type II Marine Sanitation Devices (EPA Comment Number 

EPA-HQ-OW-2010-0126-0029.2).

EcoMarine. (2010). Logistics and Consideration of Installation and Operation of AWTS, Alaska 

Cruise Ship Science Advisory Panel.

Friends of the Earth (FOE). (2010). Supplemental Information to Comments on Petition to Revise 

the Performance Standards for Type II Marine Sanitation Devices (EPA Comment 

Number EPA-HQ-OW-2010-0126-0036.1).

Griffiths, R., MacGregor, M., and Markle, S. (2008-2009). Greenwater: The Future of Sewage 

Regulations, Equipment Design, and Testing. U.S. Coast Guard Proceedings.

Hanninen, S., and J. Sassai. (2009). Estimated Nutrient Load from Wastewaters Originating 

From Ships in the Baltic Sea Area (Research Report VTT-R-07396-08).

Lake Carriers Association, Comments on Petition to Revise the Performance Standards for Type 

II Marine Sanitation Devices, EPA Comment Number EPA-HQ-OW-2010-0126-0040, 

2010.

MetCalf and Eddy. (1991). Wastewater Engineering – Treatment. Disposal and Reuse. McGrawHill Third Edition. 

Qasim, S.R. (1999). Wastewater Treatment Plants: Planning, Design, and Operation. Boca 

Raton, FL: CRC Press LLC.

Schneider, C.P., Peck, J. (2001). Great Lakes Fisheries Vessels: Status of the Fleet and 

Evaluation of Assessment and Research Needs.
Graywater Discharges from Vessels Section 6 - References

27

U.S. Army Corp of Engineers. (2009). The US Waterway System - Transportation Facts.

USEPA. (2011). Economic and Benefits Analysis of the 2013 Vessel General Permit (VGP) 

Draft Version.

USEPA. (2010). Report to Congress: Study of Discharges Incidental to Normal Operation of 

Commercial Fishing Vessels and Other Non-Recreational Vessels Less Than 79 Feet

(EPA-833-R-10-005).

USEPA. (2008a). Vessel General Permit for Discharges Incidental to the Normal Operation of 

Vessels (VGP).

USEPA. (2008b). Cruise Ship Discharge Assessment Report, December.

USEPA. (2008c). National Pollutant Discharge Elimination System Vessel General Permit Fact 

Sheet.

USEPA. (2006a). Sampling Episode Report for Holland America Veendam (Sampling Episode 

6503). Washington, DC.

USEPA. (2006b). Office of Transportation and Air Quality, Draft Report: Category 2 Vessel 

Census and Activity.

USEPA. (2006c). Holland America Line Oosterdam Sampling Episode Report.

USEPA. (1999). Uniform National Discharge Standards for Vessels of the Armed Forces –

Phase I Technical Development Document.
ATTACHMENT A:

PUBLISHED LITERATURE FROM VENDOR WEBSITES
The AHEAD TANK Type II Marine Sanitation Device is a biological Aerobic (bacteria and air) 

Sewage Treatment System. Liquid and solid wastes are removed from the water by bacteria 

naturally contained in sewage. The AHEAD TANK consists of three treatment stages; aeration, 

clarification and chlorination. In the aeration chamber (Stage 1), the bacteria grows and multiply 

using the sewage as their food supply. This action reduces the quantity and size of the solid 

matter. In the clarification chamber (Stage 2), the bacterial floc is separated from the treated 

water. The treated water is clear and free from solids; however, the liquid must be disinfected 

prior to discharge overboard to kill any disease-causing bacteria. Disinfecting is accomplished in 

the Chlorination Chamber (Stage 3) flow through these three chambers is caused by direct 

displacement. When new sewage flows into the aeration chamber, an equal volume flows into 

the clarification chamber. This volume, in turn, displaces an equal volume from the clarification 

chamber into the chlorination chamber, and overboard. No internal sewage pumps are necessary.

AERATION

Sewage is aerated as soon as it enters the treatment system and mixes with the aerated liquid 

already in the aeration chamber. EPDM Air diffuser injects air near the bottom of the aeration 

chamber so that the sewage remains in a state of aerobic decomposition. This aerated liquid 

contains the bacterial sludge that reacts with the sewage to start the reduction process. The 

movement created by the injected air helps mix the sewage with the bacterial sludge and 

prevents sludge and sewage solids from settling to the bottom. The air discharged from the 

surface of the liquid in the aeration chamber is vented to the atmosphere through a vent line 

connection.

CLARIFICATION

The liquid displaced from the aeration chamber flows into the clarification chamber for further 

treatment. Some of the suspended material will settle out into the bottom of the chamber below 

where it will return to the aeration chamber. The remaining sludge and waste material is removed 

as the liquid flows upward through the biological filter media. Bacteria grows on the surface of 

the media and produces a sticky, slimy film that traps small particles of waste. The bacteria on 

the surface of the filter media then consumes the trapped waste. By the time the liquid reaches 

the top of the filter media it has passed through several layers of bacteria, ensuring that the 

sludge and waste removal process is completed. Any floating solids are returned to the aeration 

chamber by means of an air lift pump. Clean water accumulates here until it is displaced into 

through the crossover line into the chlorination chamber.

CHLORINATION

The water flowing out of the crossover line is directed through a chlorine tablet feeder (Model 

AT-6T & AT-12T only) coming in contact with the chlorine tablets before entering the 

chlorination chamber where it is held for a residence time sufficient to complete the disinfectant 

stage of the process.
INTEGRATED SHIPBOARD WASTEWATER TREATMENT

CLEANSEA®

FEATURES

• Advanced black, grey, laundry 

and galley water treatment 

processes

• Highest level of customer 

support in the industry

• Premium marine-grade 

components

• Compact and space efficient 

design

• Available with total system 

redundancy

• Fully automated operation with 

remote monitoring

• Optional ultra filtration module 

for technical water re-use.

BENEFITS

• Lowest lifecycle treatment 

costs in the industry

• Very low energy and chemical 

use 

• Easy to operate with minimal 

maintenance

• Process resiliency independent 

of influent fluctuations

• Reliable, continuous operation 

with maximum system uptime

• Superior quality, safe effluent 

for direct discharge

Headworks BIO CleanSea shipboard wastewater treatment systems

deliver effluent quality surpassing the world’s most stringent marine

discharge standards with the lowest lifecycle treatment costs in the

industry.

Integrating premium marine-grade components, CleanSea technology

delivers environmental capabilities specifically designed to meet the tough

requirements of long-term shipboard operation.

CleanSea is designed to efficiently treat any blend of marine wastewater

streams including grey water streams from accommodation, galley, decanter

reject water, and laundry sources as well as black water.

Parameter Guaranteed 

Performance

MEPC 

159(55) Limit

ADEC 2010 

Limit

BOD5(mg/l) < 25 < 25 < 30

TSS (mg/l) < 35 < 35 < 150

Fecals (CFU/100 ml) < 14 < 100 < 14

Free Chlorine (mg/l) < 0.01 < 0.5 < 0.01

pH 6.5 – 8.5 6 - 8.5 6.5 - 8.5

Ammonia (NH3-N) (mg/L) < 28 N/A < 28

Copper (μg/l) < 87 N/A < 87

Zinc (μg/l) < 360 N/A < 360

Nickel (μg/l) < 43 N/A < 43
TYPICAL PROCESS FLOW DIAGRAM

 CLEANSEA®Integrated Process

Influent Mixing

Controlled filling from collection to aerated mixing 

balances pH and ensures consistent influent 

characteristics; this optimizes CleanSea performance 

and reduces costs and consumables. 

Primary Solids 

Removal

Primary solids are removed from the influent streams 

utilizing a fine wedgewire screen; solids are 

discharged to solids handling processes at a dry 

weight concentration of ~10%.

In systems where high load streams such as galley 

water and food waste reject water is processed, a preDAF is added prior to the bioreactors to provide 

additional pre-treatment.

The ActiveCell process employs self-regulating biofilm 

carrier technology; the ActiveCell system operates in a 

multi-stage configuration with three reactors for BOD 

removal and nitrification.

Suspended particulates are removed following the 

ActiveCell biofilm carrier process via ActiveFloat 

dissolved air flotation (DAF) technology, optimized for 

shipboard operation

Tertiary Filtration Low maintenance, self-cleaning filters achieve total 

suspended solids removal < 25 mg/L

UV Disinfection

High intensity ultra-violet lamps achieve disinfection 

providing extended coliform destruction; the multistage UV array maximizes final treatment performance 

without chemical use. 

Headworks Bio Canada

26 Bastion Square

Victoria, BC V8W 1HS

Canada

250.381.8850

hw@heaworksusa.com

INFLUENT BLACK WATER

INFLUENT GREY WATER

INFLUENT LAUNDRY WATER

INFLUENT GALLEY WATER

INFLUENT MIXING

INFLUENT MIXING

PRIMARY SOLIDS REMOVAL MULTI-STAGE MBBR PROCESS DISSOLVED AIR FLOATATION

DISSOLVED AIR FLOATATION

DISSOLVED AIR FLOATATION

DISSOLVED AIR FLOATATION PRIMARY SOLIDS REMOVAL

TERTIARY FILTRATION

TERTIARY FILTRATION

UV

UV

UV

UV

EFFLUENT STORAGE (BALLAST)

EFLUENT DISCHARGE SOLIDS HANDLING

SOLIDS RETURN

WASTE INCINERATION
Zodiac, mastering the elements.

Evac MBR

New waste water treatment
Evac has more than 30 years of experience in the design, 

manufacture and marketing of wastewater collection and 

treatment equipment for the shipbuilding industry.

Evac offers a complete range of products for wastewater 

collection and treatment:

•	 Sewage treatment plants

•	 Vacuum collecting units

•	 Vacuum toilets

Evac’s vacuum collecting units and treatment plants are 

the natural choice for shipbuilders. Because of the fact 

that the conventional sewage treatment plants do not 

meet requirements of the new IMO MARPOL resolution 

MEPC.159(55) Evac has developed a new treatment 

technology called Evac membrane bioreactor (MBR). 

Evac has a proven track record of reliable deliveries, 

worldwide support and tested effluent results.

Regulations

The Evac MBR is certified according to the new IMO 

MARPOL resolution MEPC.159(55) and meets all other 

existing regulations. This enables vessels equipped with 

the Evac MBR to operate all around the world – including 

environmentally sensitive areas. 

The IMO testing procedure outlined in MEPC.159(55) 

requires that the influent concentration of total suspended 

solids should be no less than 500 mg/l. In order to ensure 

that it will work under all conditions, the Evac MBR has been 

tested with over 2100 mg/l of total suspended solids in the 

influent concentration. This makes it the ideal solution for the 

treatment of black water collected by vacuum, a solution that 

requires no dilution water.

Advantages: 

•	 Extremely low running costs and energy consumption 

•	 Resistant to clogging and fouling of the membrane 

•	 Expected lifetime of membranes more than 10 years

•	 Small footprint

•	 Low sludge yield

•	 No continual chemical consumption 

•	 Disinfection is not required

•	 Dilution water is not required

Introduction

Discharge parameters IMO MARPOL

MEPC 159 (55)

Navy NIAG

2015 Target

Florida Evac MBR test results

TSS, mg/l 35 50 40 < 5

BOD5, mg/l 25 15 30 < 5

COD, mg/l 125 - - < 30

Faecal/Thermotolerant coliforms, 

cfu/100 ml

100 thermotolerant 

coliforms

100 0 below detection limits

Residual Chlorine, mg/l < 0.5 mg/l 0 0,5 no disinfection

pH 6,0-8,5 - - within limits

2
The Evac MBR is delivered as one complete, factory tested 

unit with all process steps mounted on one skid.

The Evac MBR process is fully automated and controlled 

through a PLC. 

Evac uses high quality Kubota membranes. Kubota 

membranes are used in more than 1,400 plants worldwide.

The Structure of the Submerged 

Membrane Unit

The Membrane Unit consists of a Membrane Case and a 

Diffuser Case. The Membrane Case accommodates multiple 

Membrane Cartridges, which are connected to a manifold 

with transparent tubes. The Diffuser Case has a Diffuser 

Pipe inside. Each Membrane Cartridge can be pulled out for 

maintenance.

The Structure of the Membrane Cartridge 

The membrane sheets are ultrasonic-welded on both surfaces 

of the membrane panel. They are made from chlorinated 

polyethylene with a nominal pore size of 0.4μm. Treated 

water permeates through the membrane sheets and internal 

spacers to come out via the nozzle.

Construction

Evac membrane bioreactor MBR 8

Mixed Liquor Flow Permeate

Membrane

3
* For black water 

Evac reserves rights for modifications. 

Further information about our company is available at our website www.evac.com.

MODEL No. of People

(vacuum)*

No. of People

(gravity)*

Hydraulic 

loading, l/day

Organic 

loading, kg 

BOD5/day

Dry weight,

kg

Wet weight, 

kg

Dimensions

L x W x H

MBR 8 25 21 1500 0,75 580 1800 1960x1050x1970

MBR 16 50 42 3000 1,50 780 3100 2460x1385x1970

MBR 24 75 63 4400 2,25 900 4150 2480x1720x1970

MBR 32 100 84 5900 3,00 1020 5170 2500x2055x1970

Vacuum collecting and treatment from a single 

source supplier

The Evac MBR can be delivered as a combined sewage 

treatment plant with integrated vacuum collecting unit and 

vacuum toilets. Using Evac as the single source supplier 

guarantees:

•	 easy trouble free installation and start-up

•	 the reliable functioning of the whole equipment chain 

– the vacuum collection and the treatment.

The advantages of a vacuum system: 

•	 lower water consumption

•	 piping is not dependent on gravity

•	 smaller bore piping, reduced installation time, reduced 

weight

•	 reduced size of holding tanks and sewage treatment plants

•	 no smells

•	 lower deck toilets without pumps

Evac standard MBR overall dimensions

Evac standard MBR

Sewage Inlet 

DN100 PN10

L

W

Discharge Outlet

DN40 PN6

Ventilation DN80

H

4
The Evac MBR is based on proven, very low maintenance 

membrane bioreactor technology, capable of filtering out 

particles as small as bacteria. Its compact footprint makes 

it ideal for retrofitting to existing vessels as well as for 

installation on new ships.

Pre-treatment:

Foreign objects must be removed before the treatment 

process. Efficient pre-treatment using screens also reduces 

organic loading, increasing the efficiency of treatment.

Biological process:

Organic waste is removed from the water during the treatment 

process. Organics are turned into carbon dioxide, water and 

biomass (MLSS). The Evac MBR is designed to operate on 

elevated concentrations of biomass. Oxygen for the biomass 

is supplied through membrane module air diffusers, whilst the 

oxygen simultaneously cleans the membranes with turbulent 

cross flow.

All bioprocesses produce surplus sludge and part of the 

biomass is removed from the process. The concentration of 

biomass in the Evac MBR is monitored and sludge removal is 

automated. 

Principle of operation

Membrane filtration:

Clean water is separated from the biomass by membrane 

filtration. Evac MBR membranes are submerged flat-sheet 

type membranes. The Evac MBR does not require any backflushing or constant chemical cleaning, making it the most 

economical and maintenance-friendly membrane solution. 

The pressure difference for the membrane filtration is only 

around 30 mbar; such a small amount of pressure acting on 

the membranes guarantees them an extremely long lifetime.

Aeration from the bottom creates an upward flow of mixed 

liquor in between the membrane cartridges. This prevents 

the membrane surface from fouling, and as a result the 

membranes only need to be cleaned twice a year.

The treated water does not need any further disinfection 

and can be discharged directly into the sea.

Permeate

Efuent

Sludge

MEMBRANE TANK

PUMPING 

TANK

Feed Pump

Screen

Black water

EQUALIZING TANK

Membrane module

Vacuum

generating

(optional)

Grey water

(optional)

Membrane tank Blower

Discharge Pump

Water equalizing

and mixing

Vacuum unit

Biological process 

and ltration

5
08/2008/2000

www.evac.com - www.zodiac-marine-pool.com/en/

Evac Oy

Finland

Tel. : +358 20 7630 200

Fax : +358 20 7630 222

evac.marine@evac.zodiac.com

Evac North America Inc.

USA

Tel.: +1 815 654 8300

Fax: +1 815 654 8306

marine.us@evac.zodiac.com

Evac Cruise Services

USA 

Spare Parts Sales:

Tel.: +1 815 654 8300

Fax: +1 815 654 8306

marine.us@evac.zodiac.com

Field Service:

Tel.: +1 954 471 5336

JAndersen@nsk.zodiac.com

Evac E.U.R.L.

France

Tel.: + 33 1 3421 9988

Fax: + 33 1 3464 3900

infofr@evac.zodiac.com

Norsk Inova AS

Norway

Tel.: + 47 35 02 97 00

Fax: + 47 35 02 97 01

norsk.inova@nsk.zodiac.com

Evac Vacuum Systems (Shanghai) Co. Ltd.

China

Tel.: + 86 21 6415 9580

Fax: + 86 21 6415 7550

info.shanghai@evac.zodiac.com

Commercial Marine Equipment

Part of Zodiac Marine & Pool
Evac is the most experienced supplier of vacuum toilets and wastewater management solutions for the ship building 

industry. 

Evac is capable of delivering a comprehensive system for the collection, treatment and discharge of both black and 

grey water. The total wastewater concept gives the shipyard and ship owner a reliable and integrated system with 

economical operation costs.

Evac products are typically most suitable for ships over 2 000 dwt, with a crew and/or passengers of 25 or more. This 

ship range covers cruise liners, coastal and ocean going cargo ships, naval vessels, car and passenger ferries, river 

cruisers, ro-ro vessels, submarines, rigs and mega yachts.

Over the last years Evac has made considerable investments in research and development on the problems of 

marine wastewater treatment. This has resulted in four treatment product ranges: advanced waste water treatment 

solutions, advanced black and black/grey water treatment solution, biological sewage treatment solutions and 

physical/chemical sewage treatment plants.

With our combination of know-how in both waste water treatment and vacuum collection, Evac can always provide 

the most suitable technical solution for the ship.

At the moment there are about 8 000 ships in operation with more than 0,5 million Evac toilets, thousands of vacuum 

units and hundreds of sewage treatment plants. 

Evac technologies are IMO and USCG certified.
Specializing in Sewage Treatment Systems for the Marine and Offshore Industries. All FAST®

(Fixed Activated Sludge Treatment) units are fully certified by USCG under U.S. and IMO 

regulations. More

Easy to install, FAST® units are ideal for everything from small commercial vessels to large cruise 

ships and ore carriers. They ship direct to the customer as factory-built assemblies, as factory-built 

modules, and as kits for installation into existing tanks. These reliable and trouble-free FAST® units 

are already capable of meeting the next generation of sewage regulations.

 

The LX-Series - This new 

economical and lightweight 

modular design is ideal for 

small commercial vessels. It 

is strong, corrosion resistant 

and will fit under the 

stairway of a tug engine 

room.

 

The M-Series - Modular 

steel units will handle crews 

of up to 60 persons and will 

fit into shaft alleys and other 

spaces with low headroom 

and restricted access.

 

The MX-Series -

Assembled versions of the 

M-Series, these compact

package units are ideal for 

workboats, dredges, 

offshore vessels and 

structures, and other 

commercial vessels.

 

The D-Series, DX-Series & 

DV-Series - For larger 

crews, these flexible 

designs offer the ultimate in 

strength, corrosion 

resistance and 

performance. They are 

available in bolt-together 

modular form for installation 

aboard existing vessels, 

such as ferries, off-shore 

platforms and ore carriers.

 
Technical Data Sheet: Water Systems

Retrofit STA-C

and ST-C Series

Super Trident Sewage

Treatment Plant

Hamworthy is the world’s leading manufacturer of marine

sewage treatment plants. For over three decades our Super

Trident sewage treatment plants have been widely regarded

as standard specification on all vessels.

Hamworthy’s STA-C/ST-C Super Trident sewage treatment

plants were one of the first plants in the market to be

granted type approval in meeting the new IMO MEPC.159(55)

standard, which employs more stringent black and grey

water effluent quality treatment guidelines. All sewage

treatment plants installed on existing ships on or after

1 January 2010, and on new ships whose keels are laid on or

after this date, must meet the new MEPC.159(55) guidelines.

The retrofit range has been specifically designed to reduce

the cost of installing sewage treatment equipment into

existing vessels. Each size in the retrofit range is built up

from three separate water tight tanks connected by external

piping, aiding installation. The dimensions of each

component has been arranged to permit its transportation

through standard vessel access ways.

Standard features

 IMO & MED certificate authorised by U.K. M.C.A.

 Modular construction

 Single power supply input point

 Minimal maintenance requirement

 Solids handling Hamworthy centrifugal discharge pump

Optional features

 Standby compressor

 Standby discharge pump

Operating Principle

Aeration compartments

Sewage enters the first of two aeration compartments via the

soil inlets and a coarse screen before being thoroughly mixed

and aerated by the aerators located at the bottom of the tanks.

The aerobic bacteria and micro organisms break down the

organic waste material into mainly carbon dioxide, water and

inert material and produce new bacteria cells and organisms.

This mixture is displaced by incoming sewage into the settling

compartment. Air, which provides the oxygen for the bacteria

and micro organisms is supplied by a rotary compressor to the

fine bubble aerators which are easily removable through the

side or end of the tank for maintenance.

Settling compartment

This section is designed to precipitate all solid material to the

bottom of the hopper as activated sludge which is then

returned by air lift back to the aeration compartments where it

is mixed with the incoming raw sewage. The clear supernatant

liquid is then displaced into the disinfection compartment. An

outlet weir is situated at the centre of the settling

compartment. This controls the flow of supernatant into the

disinfector.

Disinfection compartment

Chemical disinfection and dechlorination are dosed into the

effluent to produce a clean, safe, effluent suitable for

discharging at sea.

Standard

MEPC.159(55)

01/01/2010

(new)

100 Geom mean Land test:

35 Geom mean

On board test:

35* Geom mean

25 Geom mean 125 Geom mean 6~8.5 Best Tech Practice

<0.5

Coliform Suspended solids BOD (5) COD pH Residual Chlorine

0038/YY
Model

No.

ST2AC-(R)

ST4AC-(R)

ST6AC-(R)

ST8AC-(R)

ST2AC-(R)

ST4AC-(R)

ST6AC-(R)

ST8AC-(R)

IMO Cert.

Litres/Day

3260

5960

9200

12200

21

41

65

86

C

1398

1847

1937

2037

D

1900

2100

2550

2850

B

1678

1835

2035

2135

E

1174

1624

1724

1824

F

1265

1415

1615

1715

G

1290

1415

1765

2015

ref: HWS0072 1010

Retrofit STA-C and ST-C Series Water Systems

DISCHARGE

(SETTLING TANK)

EMERGENCY OVERFLOW

VENT TO

ATMOSPHERE FOR REMOVAL OF

LEVEL SWITCH

DISCHARGE FOR

AERATION AND

CONTACT TANKS

STANDBY COMPRESSOR

AIR COMPRESSOR

COMPLETE WITH

RELIEF VALVE &

FILTER

LIFTING LUGS CONTROL PANEL

COMBINED HIGH LEVEL,

LOW LEVEL & HIGH

LEVEL ALARM FLOAT

SWITCH

CONTACT TANK

RAW SEWAGE INLET PRIMARY AERATION TANK

SECONDARY

AERATION TANK

180

A

B

C

D

E

F

G

Size of aperture through which unit will

pass when separated into three parts with

panel, transfer tubes, chlorine tablet

magazine and vent tubes attached.

Size of aperture through which unit will pass when

separated into three parts with panel, transfer tubes and

studs, chlorine tablet magazine and

vent tubes and covers removed.

Dimensions (mm)

Hamworthy Water Systems Limited

Fleets Corner, Poole, Dorset BH17 0JT. England.

tel: +44 (0)1202 662600. fax: +44 (0)1202 668793.

e-mail: info@hamworthy.com

website: www.hamworthy.com/sewagetreatment

a subsidiary of Hamworthy plc

The manufacturers reserve the right to alter the

specification and data to incorporate improvements in design.

Certified drawings will be issued on request.

© All details copyright Hamworthy plc.

655 x 1220

730 x 1670

830 x 1770

880 x 1870

867 x 1371

942 x 1821

1042 x 1921

1092 x 2021

No. of people

(under normal gravity

collection conditions) A

2318

2518

3024

3324
The Humphrey

Type II Marine Sanitation Device

Sewage Treatment Systems for 3-75 crew.

Marine sewage treatment systems can be complicated or they can be simple. The Humphrey

Type II Marine Sanitation Devices (MSD) are designed for simplicity, are engineered with 

common sense, and will provide years of trouble-free service.

The Humphrey Type II MSD's are onboard sewage treatment systems that are fully certified by 

the USCG and are IMO* approved. Each Humphrey unit exceeds the effluent standard set by 

Pollution Act Federal Water (33 CFR159) and carries our Certification Number - to ensure 

absolute compliance with Federal laws.

Because of the possibility of future change in the law, the Humphrey is designed to yield 

effluent actually higher in quality than currently required by the USCG.

The Humphrey is:

• Flexible. By choosing to use a modular design instead of a large, bulky, all-in-one unit, 

we give you ease of installment with greater placement flexibility. Humphrey units can 

be stacked for compactness or installed remotely from each other. The system is 

flexible so you don't have to take your boat apart. Most systems can be installed in a 

matter of hours. 

• Workable. Humphrey components are usually small enough to pass through existing 

passageways - facilitating easy installation and minimizing costly down time. 

• Lightweight. If weight is a critical constraint in your application the Humphrey offers you 

the best solution. 

• Non-corrosive. By choosing to use non-corrosive materials (including a special space 

age polymer yielding strength and durability, we offer you an MSD truly compatible with 

harsh marine environment. 

• Cost Effective. Humphrey systems effectively treat waste for pennies a day per 

person. And with few moving parts, there are fewer opportunities for maintenance 

problems. Replacement parts are readily available and very inexpensive. 

• Customer Friendly. By choosing to go with field-proven technologies from the start, we 

have been able to concentrate on how the product works for our customer. From 

listening to our customers we have upgraded, refined, and expanded the product into 

today's user friendly model line which exceeds USCG requirements for effluent qualify. 
I N T E G R AT E D S H I P B OA R D WA ST E WAT E R T R E AT M E N T P RO C ESS
INFLUENT

BLACK WATER

INFLUENT

GREY WATER

INFLUENT

MIXING

INFLUENT

MIXING

PRIMARY

SOLIDS

REMOVAL

PRIMARY

SOLIDS

REMOVAL

ULTRA-VIOLET

DISINFECTION

UV

DISINFECTION

ULTRA-VIOLET

EFFLUENT

STORAGE

(BALLAST)

TERTIARY

FILTRATION

Waste Incineration

Solids Return

< 15 mg/L BOD

< 15 mg/L TSS

< 10 CFU/100mL

EFFLUENT

DISCHARGE

DISSOLVED

AIR FLOTATION

DISSOLVED

AIR FLOTATION

MULTI-STAGE

BIOFILM CARRIER PROCESS

SOLIDS

HANDLING

TERTIARY

FILTRATION

ULTRA-VIOLET

DISINFECTION

ULTRA-VIOLET

DISINFECTION

 Integrated Processes

Influent Mixing

Controlled filling from collection to aerated mixing balances pH 

and ensures consistent influent characteristics; this optimizes 

CleanSea performance and reduces costs and consumables.

Primary Solids Removal 

Primary solids are removed from the influent streams utilizing a 

fine wedgewire screen; solids are discharged to solids handling 

processes at a dry weight concentration of ~10%.

The ActiveCell process employs self-regulating biofilm carrier 

technology; the ActiveCell system operates in multi-stage 

configuration with three reactors for enhanced biokinetics.

Suspended particulates are removed following the ActiveCell 

biofilm carrier process via ActiveFloat dissolved air flotation 

(DAF) technology, optized for shipboard operation.

Tertiary Filtration

Low maintenance, self-cleaning filters achieve total suspended 

solids removal <15 mg/L; results exceed stringent Alaska State 

discharge standards by over 50%.

UV Disinfection

High intensity ultra-violet lamps achieve disinfection providing 

extended coliform destruction; the multi-stage UV array 

maximizes final treatment performance without chemical use.
Owens Manufacturing & Specialty Company was 

the FIRST to make a U.S.C.G. certified marine 

sanitation device (MSD). Whether you operate a 

single ship, or an entire fleet, our marine units are 

perfect for all of your sewage/waste treatment 

requirements. Simple operation, easy maintenance, 

long lasting reliability and optimum effluent 

compliance have kept Owens KLEEN TANK "The 

Preferred Choice" for more than 35 years. 

Owens offers custom design and manufacturing as 

well as stock units. We use state of the art 

technology and superior manufacturing practices to 

deliver a product that is IMO and U.S.C.G. certified. 

Replacement parts are readily available. 

The Owens KLEEN TANK is self-contained and 

delivered to your site ready for installation and 

operation in your vessel.

Features/Benefits

• Easy four point maintenance plan 

• Easy access covers 

• Easy access/non-corrosive valve controls 

• Low maintenance disinfection system 

• Constructed of carbon (corrosion protected) or stainless steel 

• Stainless steel weir basket - self cleaning 

• Regenerative TEFC blower - quiet 

• Float controlled effluent pump 

• Patented floating skimmer 

• Alarm system 

• Stock availability of units and parts 

• Full line of complementary products 
The Redfox Environmental Marine Model has received Bureau Veritas certification for IMO Resolution 

MEPC 159(55). The IMO Marine Environmental Protection Committee resolution applies to all sewage 

treatment systems installed onboard on or after January 1, 2010. The Marine Model is designed, 

manufactured and tested to comply with MEPC 159(55) effluent standards.

This wastewater treatment technology has been utilized by Red Fox for over (25) years. This design is 

utilized on vessel applications. 

The process used by the MSD involves the same three steps as the conventional unit, but the clarifier 

operates under a fluid head pressure allowing flocculation and settling of the solids in the clarification 

chamber to occur even when the vessel is in motion:

Coarse Screening: As the influent enters the sewage treatment unit, it passes through a bar strainer. This 

strainer will catch any large trash such as rags, plastic bags, etc., and prevent it from entering the 

system.

Aeration: Supports naturally occurring bacteria that eliminates the waste.

Clarification & Settling: Causes the separation of the bacteria sludge from the treated water.

Disinfection: Eliminates the presence of any living bacteria before discharge of the effluent into the 

environment.

RedFox Model Persons/ Black Water Persons/Black & Gray Water

RF-100-M 5 2

RF-200-M 10 4

RF-350-M 18 7

RF-500-M 25 10

RF-750-M 38 15

RF-1000-M 50 20

RF-1500-M 75 30

RF-2000-M 100 40

RF-2500-M 125 50

RF-3000-M 150 60

RF-3500-M 175 70

RF-4000-M 200 80
RF-4500-M 225 90

RF-5000-M 250 100

RF-5500-M 275 110

RF-6000-M 300 120

RF-7500-M 375 150

RF-9000-M 450 180
Waste Water System 

The international focus on discharging waste water in coastal waters is increasing. New standards for discharge and 

various regulations are driving the cruise industry to process all waste water onboard. To meet new demands and 

future requirements, Scanship offers a complete system for waste water treatment.

Scanship’s waste water system is designed to treat all types of maritime waste water, thus managing the rapid and 

significant load variations. The system reduces the need of large holding capacity onboard and increases the 

operational flexibility. The waste water system has been developed from proven land based technology, cleverly redesigned for maritime industry.

Traditional waste water plants onboard only treat black water. This represents less than 10% of the total hydraulic 

load and less than 15% of the actual pollution. Today Scanship treats 100% of the waste water in nearly the same 

space as the traditional black water treatment plants, making this the most compact solution available. In many 

cases our systems eliminates in-port discharge fees.
Purification beyond requirements!

Scanship AWP

Sustainable Solutions

Scanship as, Rambergveien 3, 3115 Tønsberg, Norway, Ph: +47 33 01 64 00 • Fax: +47 33 01 64 01 • E-mail: post@scanship.no

www.scanship.no

© ftr.no

Scanship can deliver systems for all capacities, the largest Scanship AWP systems in 

operation treats wastewater from 6 000 people onboard.

Based on long time experience in the Cruise Industry, installing and 

operating more than 25 large advanced wastewater purification 

systems for ship-owner NCL and RCCL in Alaska, a new compact 

edition is available for all marine markets.

Scanship does not stop at todays effluent requirements set forth in 

the Alaska Murkowski Bill and IMO Marpol MEPC 159/55. We exceed 

the standards to make your ship the greenest in the worlds fleet! We 

guarantee the treated effluent from the Scanship AWP to be in 

accordance to the Alaska Standard for Continuous Discharge and all 

classification societies Cleanship Superior Notation.

Scanship AWP removes organic matters, suspended solids, bacteria 

and nutrients such as phosphorus and nitrogen. The technology 

combines mechanical and chemical separation with an patented 

biofilm process with BOD removal and Nitrification/Denitrification. All 

bacteria is removed from the effluent with advanced UV technology. 

Scanship AWP treats all wastewater sources onboard, such as black 

and grey water, accomodation grey, laundry water and galley water 

inclusive food waste rejects. The process is robust, easy to operate 

without the hassels of clogging (none membrane technology). 

The process provides a crystal clean effluent discharge. As a 

reference, Cruiseliners equipped with Scanship AWP systems has 

obtained continous discharge permits in Hawaii and Alaskan waters, 

and in numerous European ports such as Venice and Oslo ever since 

2003.

Model Capacitiy Load Installed Power Dimensions (m) Weight (kg) 

pax/crew m3/d kg BOD5/d KW W L H Dry Wet

S25PE 30 5 6 8 1,8 1,9 2,0 900 3200

S60PE 60 15 12 12 1,8 3,3 2,0 1200 5800

S120PE 120 24 24 18 1,8 4,8 2,0 1600 8500

S25PE

S60PE

S120PE

L

W

H

A proven technology for clean discharge in the maritime world

Superyacht

Navy - Military

Cruise & Ferry

Merchant Shipping

Offshore Oil & Gas

Ports & Resorts
ATTACHMENT B:

SUMMARIES OF INFORMATION GATHERED IN TELEPHONE CONVERSATIONS
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Marine Equipment Division of Smith and Loveless, Inc. –FAST SYSTEMS

Sunset Hills, MO

Contact: David Predau

Phone: 314 645 6540

Date: December 10, 2010

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI; however, we are not able to receive CBI information at this time. Data that is not claimed 

as CBI can be used publicly without notice to Smith and Loveless.

Overview:

The marine equipment division of Smith and Loveless, Inc. manufactures and sells the Fixed Activated 

Sludge Treatment (FAST) System; a U.S. Coast Guard (USCG)1 and IMO Resolution MEPC 159(55)2

approved Type II MSDs. Systems can be installed on vessels having as few as 6 passengers and crew and 

are designed to treat sewage (blackwater), but can treat commingled blackwater and graywater. According 

to Mr. Predau, 99 percent of their installations are for treatment of blackwater only. FAST systems have 

been installed on tow boats, tug boats, crew boats and off-shore platforms. According to Mr. Predau, 

graywater sources could include showers and sinks, but not galley due grease problems, or any graywater 

containing constituents that may be toxic to the system such as Lysol. The system treats fecal coliform 

bacteria, TSS, BOD and COD. The system is not designed to treat ammonia or phosphorous. 

FAST systems are fixed-bed biological treatment. According to Mr. Predau, sewage enters an aeration tank 

where the microorganisms grow on fixed media within the aeration tank. Accumulated solids from 

biological treatment settle by gravity into the bottom of the aeration tank where they are removed every 3 

months. Effluent from clarification flows through a disinfection system containing chlorine tablets. 

According to Mr. Predau, the system requires little to no operator attention. Water pumps and the airlift 

pump operate continuously, and there are not other moving parts. The system is typically not tied to the 

ship’s controls to determine if all mechanical systems are in operation. There is no monitoring equipment 

(e.g., turbidity meters, etc.) or other mechanisms to verify effluent quality. No effluent monitoring is 

performed to verify compliance according to Mr. Predau since the system is type certified using a 10-day 

test, and on-board monitoring is therefore not required. The system can withstand a couple of weeks 

without flow. FAST systems have a relatively small foot-print according to Mr. Predau and can be retrofit 

on existing vessels to replace more common maceration and chlorination systems.

 1 USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 

100 CFU/100 ml fecal coliforms, 0.5 mg/L TRC, and pH 6 to 8.5.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

EVAC - ZODIAC Systems

Washington State

Contact: Shirley Fredrick

Phone: 815 639 7725

Date: November 18, 2010

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI, however we are not able to receive CBI information at this time, and that data that is not 

claimed as CBI can be used publicly without notice to EVAC.

Overview:

After explaining why ERG was contacting EVAC, Shirley asked if EPA was going to require numeric 

effluent limits for graywater like USCG does for sewage systems, when that may happen, and if existing 

treatment systems would be “grandfathered”. We stated we were contractors and could not provide answers 

to those questions. Instead we provided her with Robin Danesi and Ryan Albert’s contact information if she 

wished to discuss the VGP program with them.

EVAC manufactures a membrane bioreactor (MBR) certified to IMO Resolution MEPC 159(55)

1

standards. EVAC is currently in the process of getting US Coast Guard certification for the MBR for use in 

US waters. The system is not certified for continuous discharge in Alaska, although the discharge testing 

data indicates the system would provide sufficient effluent quality for continuous discharge in Alaska. 

Systems can be installed on vessels having a minimum of 25 passengers with a vacuum toilet system or 21 

passengers with a gravity system. The system can treat only sewage, commingled sewage and graywater, or

graywater only. If graywater only is treated, one source must be galley wastewater to provide sufficient 

BOD/organics for the microorganisms; however, pretreatment must be performed on galley water to 

remove grease and a macerator should always be installed as well. Systems are sized based on the specific 

influent BOD to the MBR and are therefore custom built for each particular vessel. 

There are approximately 300 EVAC MBRs operating throughout the world, however only 2 are being used

in the United States; on a military vessel (TAG 66) and the other on an oceanographic vessel. The systems 

have been installed on cruise ships and other non-US military vessels. Shirley will email a list of vessel 

types and possibly contacts which the EVAC has been installed throughout the world. EVAC systems may 

require a pretreatment that includes screening to remove items that can not be macerated. Pretreatment 

systems are sold separately. Treatment begins with initial maceration and flow/loading equalization. 

Effluent from equalization enters the two aerated membrane tanks where biological treatment removes 

BOD. Effluent from the tank flows through membranes suspended in the tank. The membranes are 

constantly scoured by the air bubbles in the tank, so physical cleaning is only required a couple times per 

year. Sludge from the system is removed every 3 weeks to prevent excessive mixed liquor solids. Sludge 

is placed in a separate tank for proper disposal. It is estimated that in a blackwater only system, 3% will 

become sludge. There is no disinfection system for the EVAC. According to Shirley, the membrane 

systems produce an effluent that is free of bacteria. Shirley directed ERG to the certification literature 

which indicted fecal coliform bacteria in the effluent from the 14-day IMO certification test were below 

detection.

 1 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 

100 CFU/100 ml fecal coliforms, 0.5 mg/L TRC, and pH 6 to 8.5.
According to Shirely, the system does require operator attention. She indicated 2-3 hours per week to 

monitor sludge/solids levels. Shirley also stated the system requires a constant flow with sufficient BOD 

for the organisms, and shutting down the system is not recommended. She indicated that it can take 2 

weeks to grow sufficient bacteria for the system to be restarted. The system can be tied to the ships 

controls so the operators can verify the systems are operating. Systems are equipped with alarm systems to 

verify they are operating within the hydraulic parameters. There is no monitoring equipment (e.g., turbidity 

meters, etc.) or other mechanisms to verify effluent quality that she was aware of. However, the system 

detects pH and self-adjusts as needed. 

EVAC does not install equipment on vessels, but instead sells the certified systems to the ship 

builder/contractors. They do assist with the initial system start-up but do not do follow-up system 

verification after startup. Shirley stated the systems are large and a significant footprint and weight bearing 

requirement is needed. Retrofits can be done; however, it is typically done when the vessel is doing other

types of major reconstruction. 

Shirley stated we could have an operating manual, however it can not be shared since it is CBI. ERG stated 

we can not take CBI information at this time and to not send the manual.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Hamann AG – Filwatec US

Oakland Park, Fl

Contact: Rudy Goeth

Phone: 954 537 4735

Date: November 18, 2010

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI, however we are not able to receive CBI information at this time, and that data that is not 

claimed as CBI can be used publicly without notice to Hamann AG.

Overview:

Hamann AG manufactures a U.S. Coast Guard (USCG)1 and IMO Resolution MEPC 159(55)2 approved 

Type II MSD. The system is not certified for continuous discharge in Alaska. Systems can be installed on 

vessels having between 10 and 800 passengers to treat commingled sewage and graywater. The system can 

not treat only sewage, or only graywater. Hamman AG Type II MSDs have been installed primarily on 

mega yachts and small passenger vessels. None have been installed on ferries or cargo ships. The new 

IMO Resolution MEPC 159(55) certified systems have not yet been installed on cruise ships, but they can 

be if a cruise ship has an interest. Graywater sources include showers and sinks, but not galley due grease 

problems. The system treats bacteria, TSS, and BOD. It is not designed to treat ammonia or phosphorous. 

Hamann systems are physical/biological. Sewage is initially macerated before entering a tank similar to a 

dissolved air flotation unit. Air bubbles in the tank cause solids to float while providing dissolved oxygen 

for biological treatment. Floated sludge from the system is collected and placed into a separate tank where 

it is either discharged outside 12 nm or shore-side. The system does not use membrane filters or chlorine. 

Effluent from the aeration tank passes into a UV light disinfection chamber. Sea water does enter the 

system for pump seals and other processes (process water) which does dilute the wastewater. Rudy had no 

idea how much seawater is actually added to the system as process water. 

According to Hamann, the system requires little to no operator attention. Pumps, sludge skimmers, 

compressors and blowers operate continuously. The system can be tied to the ships controls so the 

operators can verify the systems are operating. There are sensors/alarms for high level, pressure in the 

dissolved oxygen tank, UV light, and no effluent. There are no monitoring equipment (e.g., turbidity 

meters, etc.) or other mechanisms to verify effluent quality. The system can withstand a week without 

flow, and requires less than 1 hour to restart the system. Hamann also stated the systems are modular and 

have been retrofit on vessels. 

Hamann does a retest of the system approximately 6 months after the unit has been installed on a vessel to 

verify its operating properly. After that, periodic effluent testing is based on the any voluntary sampling 

done by the ships crew. Hamann did the initial IMO certification in a laboratory in Germany for their 

system, and Rudy stated that test data for certification was considered CBI and is therefore not available to 

ERG and EPA. 

 1[1] USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2[2] IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 

100 CFU/100 ml fecal coliforms, 0.5 mg/L TRC, and pH 6 to 8.5.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Headworks Bio, Inc.

Contact: Graham Dempster

Location: Victoria, BC

Phone: 250-381-8850

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on traditional Type II MSDs and Advanced Wastewater Treatment Systems (AWTS) 

for graywater as part of the reissuing the Vessel General Permit (VGP). ERG also explained that any 

responses can be claimed as CBI; however, we are not able to receive CBI information at this time. Data 

that is not claimed as CBI can be used publicly without notice to Headworks Bio.

Overview:

Headworks Bio acquired the assets of Hydroxyl Services, Inc. in bankruptcy proceedings in 2009. 

Headworks Bio manufactures and sells the CleanSea advanced wastewater treatment system (AWTS) that 

has been type certified by both U.S. Coast Guard (USCG)1 and IMO Resolution MEPC 159(55)2

. The 

CleanSea system is also approved for continuous discharge in Alaska by ADEC. Systems are designed for 

large cruise ships with at least 1,000 passengers (500 to 3,000 m3

/day flow). The system is installed on the 

largest cruise ship in the world - Royal Caribbean’s Oasis of the Seas with 8,000 persons on board. The 

system is currently operating on 10 large cruise ships: 7 Royal Caribbean cruise ships and 3 Celebrity 

cruise ships. The system is a moving bed biological reactor (MBBR) and is designed for the removal BOD, 

COD, TSS, fecal coliform bacteria, and ammonia nitrogen. The CleanSea system can treat all types of 

blackwater and graywater, including food pulper filtrate (i.e. food pulper wastewater that has been 

screened). Systems can treat blackwater only or commingled blackwater and graywater; however, no one 

is only treating graywater with a CleanSea system according to Graham. For example, on the Oasis of the 

Seas, 7% to 10% of flow to the treatment system is from blackwater, 50% is from hotel operations (sinks, 

showers, etc.), 15% from laundry, and the remaining volume (20% to 30%) are from other sources 

according to Mr. Dempster. Headworks Bio has retrofit the CleanSea system on 7 large cruise ships to 

date. Mr. Dempster stated that since the systems are very large, they can only be retrofit onto vessels 

having existing advanced wastewater treatment systems; they can not be retrofit into spaces originally 

designed for traditional Type II MSDs that performed only maceration and chlorination. 

Treatment begins with initial solids removal using screens and dissolved air flotation (DAF). Effluent from 

the DAF enters the MBBR system, which is an aerobic process containing thousands of polyethylene 

biofilm carriers suspended in mixed motion in the aeration tank. The polyethylene carriers provide a 

surface for the heterotrophic and autotrophic bacteria to attach. Effluent from the aerated MBBR tanks 

flows into dissolved air flotation tanks for solids removal, followed by optional mixed media filters to 

remove fine solids. After final filtration, the effluent is disinfected using UV lamps. The system is 

designed for nitrification to meet Alaska Water Quality Standards for ammonia. To date, Headworks has 

not installed denitrification on a vessel, but they are currently looking into the issue due to the new Baltic 

States requirements for total nitrogen removal. 

 1 USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 100 CFU/100 ml 

fecal coliforms, pH 6 to 8.5.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Owens Manufacturing and Specialty Co.

Contact: Stephen (New Owner)

Phone: 800-639-2744

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI, however we are not able to receive CBI information at this time, and that data that is not 

claimed as CBI can be used publicly without notice to Owens Manufacturing.

Overview:

Owens Manufacturing and Specialty Company manufactures U.S. Coast Guard (USCG)1 and IMO 

Resolution MEPC 159(55)2 approved Type II MSDs. Systems can be installed on vessels having between 3 

and 350 passengers when treating only sewage, and between 1 and 120 passengers when treating 

commingled sewage and graywater. Owens Type II MSDs have been installed primarily on tug boats, lift 

boats, drilling vessels, tow boats and very few ferries, but not cruise ships. The system is capable of 

treating only sewage, or commingled graywater/sewage at a ratio of 2 to 1 by volume. The system is not 

capable of treating only graywater. Graywater sources include showers, sinks, galley and some ground 

food waste. Grease should be removed from graywater sources before entering the system. The system 

treats bacteria, TSS, and BOD. It is not designed to treat ammonia or phosphorous. 

Owens’s systems are biological. Sewage enters into a catch basin where large non-biodegrabable items are 

filtered out. Sewage then enters an aeration chamber where air is forced through a diffuser. Bacteria 

present in the aeration chamber digest solids and organic matter. Wastewater is then transferred to a solids 

settling chamber, where the heavier solids settle. These are directed back to the aeration chamber for 

further treatment. Floating solids are also captured using floating airlift skimmers, and are transferred back 

to the aeration chamber for further treatment. Wastewater is transferred over baffles and weirs into a 

chlorine contact chamber (tablet calcium hypochlorite) for 30 minutes. Treated effluent passes through a 

carbon bed to remove residual chlorine before discharge overboard. Sludge generated onboard is not 

processed, but is held for either discharge at sea or discharge to a land-based treatment system.

According to Owens, the system requires little to no operator attention. Blowers on the system provide 

aeration on a 15 minute on-off cycle, and the blower system should remain operational, even when there is 

no flow to the system. Owens stated the system can withstand a period of approximately 4 days without 

flow. Owens also stated the systems have been retrofit on vessels, typically to replace existing MSDs.

Owens recently developed data for recertification of the Type II MSD to the IMO Resolution MEPC 

159(55) standards; however, Stephen stated that test data for recertification was considered CBI and is 

therefore not available to ERG and EPA. 

 1 USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 

100 CFU/100 ml fecal coliforms, pH 6 to 8.5.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Red Fox Environmental Services, Inc.

Youngsville, LA

Contact: Brooks

Phone: 337 856 3709

Date: November 16, 2010

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI, however we are not able to receive CBI information at this time, and that data that is not 

claimed as CBI can be used publicly without notice to Red Fox Environmental Services.

Overview:

Red Fox Environmental Services manufactures U.S. Coast Guard (USCG)1and IMO Resolution MEPC 

159(55)2 approved Type II MSDs. Systems can be installed on vessels having between 3 and 1,250 

passengers when treating only sewage, and between 1 and 500 passengers when treating commingled 

sewage and graywater. Red Fox Type II MSDs have been installed primarily on tug boats, drilling vessels, 

tow boats and ferries and pleasure yachts, but not cruise ships. The system has been installed on about 

5,200 vessels. The system is capable of treating only sewage, or commingled graywater/sewage at a ratio of 

2 to 1 by volume, but works best with commingled wastewater. The system is not capable of treating only 

graywater. Graywater sources include showers, sinks, galley and some ground food waste. According to 

Brooks, if the material in the graywater is biodegradable, it can be discharged to the Type II MSD, 

including ground food waste. Grease should be removed from graywater sources before entering the 

system. The system treats bacteria, TSS, and BOD. It is not designed to treat ammonia or phosphorous. 

Red Fox’s systems are biological and include a four step process which includes coarse screening, aeration, 

clarification and settling, and disinfection. As the influent enters the sewage treatment unit, it passes 

through a bar strainer. This strainer will catch any large trash such as rags, plastic bags, etc., and prevent it 

from entering the system. Aeration supports the naturally occurring bacteria that eliminates the waste, and 

clarification and settling causes the separation of the bacteria sludge from the treated water. The clarifier 

operates under a fluid head pressure allowing flocculation and settling of the solids in the clarification 

chamber to occur even when the vessel is in motion. Final disinfection is accomplished with chlorine 

tables, although a chlorine generator can be retrofit to the system. He stated at they have tried to operate the 

system with a UV unit instead of using chlorine tablets, but UV maintenance is too costly. 

According to Owens, the system requires little to no operator attention. According to Brooks, an operator 

should inspect the system daily to ensure all systems are operating. Blowers on the system should operate 

continuously to provide aeration to the bacteria. Red Fox stated the system can withstand a period of 

approximately 2 to 3 weeks without flow. Red Fox also stated the systems have been retrofit on vessels.

Red Fox recently developed data for recertification of the Type II MSD to the IMO Resolution MEPC 

159(55) standards. Brooks stated the data may be available, but ERG would need to send an email 

requesting the information. 

 1 USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 

100 CFU/100 ml fecal coliforms, 0.5 mg/L TRC, and pH 6 to 8.5.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Rochem

Fort Lauderdale, Florida

Contact: Eric Neuman

Phone: 954 523 6299

Date: December 6, 2010

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI; however, we are not able to receive CBI information at this time. Data that is not claimed 

as CBI can be used publicly without notice to Rochem.

Overview:

After explaining why ERG was contacting Rochem, Rochem explained they market two systems for vessel 

blackwater and graywater treatment: a low-pressure reverse osmosis system and a membrane bioreactor

(MBR). The MBR is used on all sizes of vessels, from large cruise ships to vessels as small as mega-yachts. 

The MBR system is currently IMO MEPC 159(55) certified; both systems are US Coast Guard certified. 

According to Eric, Rochem systems can handle all types of graywater except dewatered food pulper. 

Rochem systems were originally designed for blackwater treatment and do not require graywater for 

operation. Rochem MBR systems do require blackwater for proper operation. Systems can treat galley 

wastewater with some oil and grease, but do not perform well with high levels of grease or cooking oils. 

Rochem systems have been retrofit on to a number of the Seaborn medium-size cruise ships operated by 

Carnival Cruise Lines. According to Mr. Neuman, the Rochem systems have a smaller footprint than 

biological Type II MSDs and typically can be substituted for these systems. However, the system is much 

larger than maceration/chlorination systems like the Hamman systems installed on Royal Caribbean 

vessels; therefore, retrofit in these systems would not be possible. Rochem systems have been installed on 

a variety of non-US Naval vessels. Rochem systems have been certified on a number of vessels operating 

in Alaska. 

Rochem systems do not require small vessels to hire a specific operator for the MBRs; although, the large 

cruise ships sometimes do hire an operator. Typically, operation of the system is performed by the vessel 

engineer who is operating other systems such as the vessel’s HVAC system. Mr. Neuman stated the 

Rochem systems can go without feed for 24 hours, but extended periods can result in poor effluent quality. 

He stated that some cruise ships do performance sampling to verify the systems are operating appropriately, 

but Rochem does not generally do on-going performance sampling. Sampling is the responsibility of the 

vessel operator. He went on to state that a number of the type-certified MSDs installed on vessels are not 

discharging effluent that are in compliance with USCG standards, and EPA is now beginning to take a look 

at the effluent quality from these types of systems. 

Mr. Neuman stated he would be interested in participating in EPA’s vessel listening session scheduled for 

December 15, 2010 and Kathleen Wu would email him the information on how to participate in the 

conference call. 
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Type II MSD and AWTS Vendors

Scanship Americas, Inc.

Contact: Alex 

Location: Davie, Florida 

Phone: 954 651 6205

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting 

available information on Type II MSDs and Advanced Wastewater Treatment Systems for graywater as 

part of the reissuing the Vessel General Permit (VGP). ERG also explained that any responses can be 

claimed as CBI; however, we are not able to receive CBI information at this time, and that data that is not 

claimed as CBI can be used publicly without notice to Scanship.

Overview:

Scanship manufactures U.S. Coast Guard (USCG)1 and IMO Resolution MEPC 159(55)2 approved Type II 

MSDs. Scanship systems are also approved for discharge in Alaska. Systems can be installed on vessels 

having as few as 100 persons. Scanship is currently installing a system for Chevron on a ferry in Australia 

that is being used as a floating living platform for employees. It is the smallest vessel this system is 

installed on. The ferry will have between 300 and 400 persons on board. The system is located in 

“sensitive waters” and Scanship is providing the system for continuous discharge. All Scanship systems 

are aerobic biological treatment with dissolved air flotation for solids removal. Solids collected from the 

systems are centrifuged and packaged for on-board incineration. Scanship systems can treat all types of 

blackwater and graywater, including food pulper wastewater; however, food pulper wastewater can cause 

“hiccups” in the system. As a result, vessels are now centrifuging the food pulper wastewater to remove 

solids, and only the liquid fraction is being sent to the treatment system. Systems can operate treating

blackwater only or commingled blackwater and graywater; however, no one is treating only graywater with 

a Scanship system. Alex stated that approximately 60 percent of the Scanship systems currently being sold 

are retrofits, and that all new systems have nitrification and denitrification. Systems are large and are 

typically not designed for vessels with small numbers of passengers such as cargo ships. He stated these 

ships typically hold wastewater and discharge in the open ocean.

To meet Alaska water quality standards for ammonia nitrogen, Scanship has recently installed a 

nitrification-denitrification system on the Norwegian Star. The nitrification-denitrification system includes 

a pure oxygen system to increase aeration capacity and a final non-aerated anoxic denitrification tank. 

Alex stated there is a recycle loop from the anoxic tank to the aeration tank to provide alkalinity and pH 

control for nitrification. He said that nitrification consumes alkalinity and denitrification generates 

alkalinity so a portion of the denitrification effluent is recycled to balance alkalinity. The Norwegian Star 

is currently sailing between Los Angeles and the Mexican Baja peninsula. On-board engineers are 

currently fine-tuning the nitrification-denitrification system for nitrogen removal so that when the vessel 

returns to Alaska in the spring, effluent will achieve the Alaska Water Quality Standard. Once the system 

has been fine-tuned, the nitrification/denitrification will be operated continuously regardless of the vessel’s 

location since it can take up to 2 months to get the system up and running properly according to Alex. 

Alex stated the Scanship system can withstand a period of approximately 1 week without flow/feed. After 

 1 USCG has the following limits: 150 mg/L TSS and 200 CFU/100 ml fecal coliforms.

2 IMO Resolution MEPC 159(55) has the following effluent limits: 25 mg/L BOD, 35 mg/L TSS, 125 mg/L COD, 100 

CFU/100 ml fecal coliforms, pH 6 to 8.5.
a week, the vessel must start feeding sugar water to keep the system operating. Operator attention for the 

system is approximately 2-3 hours per day. Real-time data collection from the system includes TSS, UV 

light intensity for the disinfection system and pH. These parameters allow the operators to continuously 

monitor the system. 
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Small Passenger Vessels

AEP River Operations

Contact: Matt Lagarde

Location: St. Louis, MO

Phone: 225 562 5050

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting available 

information on graywater management from small passenger vessels as part of the reissuing the Vessel General 

Permit (VGP). ERG also explained that any responses can be claimed as CBI; however, we are not able to receive 

CBI information at this time. Data that is not claimed as CBI can be used publicly without notice to AEP River 

Operations.

Overview:

AEP River Operations (AEP) operates 23 tug boats on the Mississippi River. Twenty-one of the 23 tugs have 6 man 

crews, and two tugs have 9 man crews. Each vessel has a Type II MSD manufactured by Owens KleenTank that 

provides biological treatment and chlorine tablet disinfection. All of the tugs used by AEP River operations were 

constructed in 2007. Graywater generated by the vessels include accommodations, galley and laundry. In 

anticipation of new discharge standards for graywater, AEP specified in the design of the 2007 tugs that all 

graywater be piped to the disinfection portion of the Type II MSD to remove bacteria prior to overboard discharge. 

According to Mr. Legarde, this is not common on most tug boats. Older tugs discharge graywater directly 

overboard with out treatment. In addition, there is typically no holding capacity (tankage) for graywater on board 

tug boats. 

When asked about possible discharge to shore-side treatment facilities, Mr. Legarde stated that it’s not possible for 

tug boats. Tugs are fueled by other vessels that pull along side as the tug is managing barges in the middle of the 

river. If graywater was to be discharged to shore-side facilities, holding tanks would need to be installed on the tugs, 

and other vessels would need to pull along side tug when in operation to off-load graywater. Mr. Legarde stated that 

management of graywater in this fashion is not practical since most vessels such as those delivering fuel do not want 

to mix water into their tanks. There are currently no operators on the river system that are receiving graywater that is 

then taken to shore for disposal.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Small Passenger Vessels

AEP River Operations

Contact: Matt Lagarde

Location: St. Louis, MO

Phone: 225 562 5050

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting available 

information on graywater management from small passenger vessels as part of the reissuing the Vessel General 

Permit (VGP). ERG also explained that any responses can be claimed as CBI; however, we are not able to receive 

CBI information at this time. Data that is not claimed as CBI can be used publicly without notice to AEP River 

Operations.

Overview:

AEP River Operations (AEP) operates 23 tug boats on the Mississippi River. Twenty-one of the 23 tugs have 6 man 

crews, and two tugs have 9 man crews. Each vessel has a Type II MSD manufactured by Owens KleenTank that 

provides biological treatment and chlorine tablet disinfection. All of the tugs used by AEP River operations were 

constructed in 2007. Graywater generated by the vessels include accommodations, galley and laundry. In 

anticipation of new discharge standards for graywater, AEP specified in the design of the 2007 tugs that all 

graywater be piped to the disinfection portion of the Type II MSD to remove bacteria prior to overboard discharge. 

According to Mr. Legarde, this is not common on most tug boats. Older tugs discharge graywater directly 

overboard with out treatment. In addition, there is typically no holding capacity (tankage) for graywater on board 

tug boats. 

When asked about possible discharge to shore-side treatment facilities, Mr. Legarde stated that it’s not possible for 

tug boats. Tugs are fueled by other vessels that pull along side as the tug is managing barges in the middle of the 

river. If graywater was to be discharged to shore-side facilities, holding tanks would need to be installed on the tugs, 

and other vessels would need to pull along side tug when in operation to off-load graywater. Mr. Legarde stated that 

management of graywater in this fashion is not practical since most vessels such as those delivering fuel do not want 

to mix water into their tanks. There are currently no operators on the river system that are receiving graywater that is 

then taken to shore for disposal.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Small Passenger Vessels

American Cruise Lines

Contact: John Ayer

Location: Gulfport, CT

Phone: 203 453 6800

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting available 

information on graywater management from small passenger vessels as part of the reissuing the Vessel General 

Permit (VGP). ERG also explained that any responses can be claimed as CBI; however, we are not able to receive 

CBI information at this time., Data that is not claimed as CBI can be used publicly without notice to American 

Cruise Lines.

Overview:

American Cruise Lines operates 4 small cruise ships along the Atlantic coast of the United States, and one vessel in 

the Columbia River. Home ports include Bangor and Portland, Maine; Providence, Rhode Island; New York City;

Baltimore, Maryland; and Charleston, South Carolina. American Cruise Lines also travel up the Hudson River to 

Troy, New York. The vessels are approximately 210’ in length and carry 98 passengers and 25 crew members. 

Vessels traveling along the Atlantic coast are less than 3 nautical miles from shore approximately 60 percent of the 

time. Each vessel has a Type II MSD that provides maceration and chlorination of blackwater only. Mr. Ayer did 

not know the vendor for the Type II MSDs treating blackwater. In addition, Mr. Ayer did not have any information 

on the volume of blackwater or graywater generated by the American Cruise Line vessels.

Graywater generated by the vessels include accommodations, galley and laundry. Graywater is discharged directly 

overboard, except when the vessels are in No Discharge Zones (NDZs). In those instances, graywater is held in onboard holding tanks and is then either discharged when the vessel leaves the NDZ, when the vessel is outside 3 

nautical miles, or to shore-side facilities. Treated blackwater is also held in holding tanks when the vessels are in 

NDZ and then discharged overboard when outside the NDZ, outside 3 nm, or to shore-side facilities. Mr. Ayer 

stated the vessels try to limit graywater generation through low-flow shower heads, and all soaps and detergents are 

biodegradable and do not contain phosphates. 

Mr. Ayer was aware of the VGP and said each of his 5 cruise ships have permits. He commented that if EPA was 

considering making vessels treat graywater to specific standards like the USCG standards for blackwater, they 

should first consider installing more shore-side receiving stations. He said there is a station in Bangor, Maine that 

receives wastewater from holding tanks, and in Troy, New York wastewater is trucked off the dock for shore-side 

treatment. He indicated that large docks have some shoreside receiving stations and many of the small marinas have 

shore-side receiving stations for large yachts, but their 200’ vessels are too large to hook up to these systems. He 

feels that it would be far more cost effective to install shore-side receiving stations than to force all vessels to install 

more advanced and larger MSDs to treat graywater.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Small Passenger Vessels

Anglo-Eastern Container Ships

Contact: Anuj Chopra

Location: Stanford, Texas

Phone: 281 265 4814

Date: January 4, 2011

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting available 

information on graywater management from small passenger vessels as part of the reissuing the Vessel General 

Permit (VGP). ERG also explained that any responses can be claimed as CBI; however, we are not able to receive 

CBI information at this time. Data that is not claimed as CBI can be used publicly without notice to Anglo-Eastern.

Overview:

Anglo-Eastern operates 40 U.S. flagged large container ships. Vessel ports include the Gulf Coast, Mid-Atlantic 

Coast, Pacific Coast (California) and Northwest Coast. Container vessels generally have a crew of 22 to 23 persons, 

but crews can range between 19 and 27 persons depending on vessel size. According to Mr. Chopra, cargo ships 

generate both graywater and blackwater. Blackwater is routed to the Type II MSD, all of which are maceration and 

chlorination on the Anglo Eastern vessels. While in port or within 3 nautical miles of shore, graywater is held in the 

vessels’ aft peak ballast tank and is then discharged directly overboard without treatment once the vessel is outside 3 

nm. According to Mr. Chopra, Anglo-Eastern must ask for permission from the State jurisdiction to place untreated 

graywater in ballast tanks. Graywater on the vessels is generated from the galley, sinks, showers and laundry. 

According to Mr. Chopra, the Anglo-Eastern container ships can be in port from 24 hours up to 7 days which poses 

a problem for graywater storage. According to Mr. Chopra, vessels use approximately 18 tons/day of potable water. 

Approximately 4 tons is used in the engine room, 3-4 tons is for sewage (blackwater) and the remaining 10 tons/day 

is for graywater generation. Between 3 and 4 m3/day of graywater is generated by the galley. Anglo-Eastern is 

very concerned with placing graywater in the after-peak ballast tank. The tank can not be easily cleaned and 

residual solids that remain in the tank from graywater could become septic and generate hydrogen sulfide. Crew 

that must periodically enter the tank for inspection typically monitor for oxygen levels only. Mr. Chopra is also 

concerned that upcoming numeric ballast water regulations may prevent him from placing treated sewage and 

graywater in ballast tanks. He stated their Type II MSDs are type certified and he is not sure if they are actually 

working to their type certification standards. He said that sampling is never required and because of this he may be 

placing treated effluent with very high TSS and fecal coliforms in his ballast tanks that may cause problems with 

future ballast numeric standards.

Mr. Chopra feels the solution to graywater and also treated sewage is the installation of shore-side receiving 

facilities. He stated that Ango-Eastern docked vessels 1,100 times at U.S. ports last year and not one port had 

sewage and graywater receiving facilities. At one location near Portland, Oregon last year one, one vessel needed to 

off-load graywater from a ballast tank to allow the vessel to move up river. The cost to truck 25 m3 of graywater 

was $26,000. According to Mr. Chopra, this has a significant impact on the profit for container vessels. 

Mr. Chopra would like EPA to visit their vessels to see first-hand how they manage graywater, the difficulty in 

holding graywater for extended periods of time in ballast tanks, and the problems with trying to clean ballast tanks.
Graywater Discharges from Vessels

EP-C-09-020, Work Assignment 1-10, Subtask 2A

Telephone Questions for Identified Small Passenger Vessels

Horizon Lines

Contact: Wally Becker

Location: New Jersey

Phone: 908 936 1802

ERG initially identified themselves as contractors to USEPA and explained that EPA was revisiting available 

information on graywater management from small passenger vessels as part of the reissuing the Vessel General 

Permit (VGP). ERG also explained that any responses can be claimed as CBI; however, we are not able to receive 

CBI information at this time. Data that is not claimed as CBI can be used publicly without notice to Horizon Lines.

Overview:

Horizon Lines operates 26 U.S.-flagged large container ships. Vessel ports include New York City; Jacksonville, 

Florida; San Juan, Porto Rico; Guam; Hawaii; and Alaska. Container vessels generally have a crew of 26 persons. 

According to Mr. Becker, cargo ships generate both graywater and blackwater. Blackwater is routed to the Type II 

MSD, all of which are maceration and chlorination on the Horizon Line vessels. Graywater is discharged directly 

overboard without treatment. Tanks could be made available to hold graywater while the vessel is within 3 nautical 

miles; however, significant piping changes would be required. Graywater generated onboard the cargo ships include 

accommodations (sinks, showers), galley and laundry. All graywater from the galley passes through a grease trap to 

remove floating oils prior to discharge.

According to Mr. Becker, the Horizon Cargo ships are typically in port for 12 hours to unload and load containers 

before they head back to sea. Mr. Becker indicated that for some ports like New York Harbor, it can take up to 3 

hours to dock and another 3 hours to go underway, so the total time the vessel is within 3 nm of shore could be up to 

18 hours. Cargo ships that travel along the United States coast are typically 25 nm from shore. The shortest voyage 

for a Horizon Line cargo ship is 1 week, but most are 2 weeks. Travel from the west coast of the United States to 

Asia is a 35 day voyage. 

While the vessels are in port, the primary graywater that is generated is galley wastewater, since the crew needs to 

be feed during the unloading/loading time. Graywater from accommodations and laundry is typically generated 

when the vessel is on route to the next port, which is outside the 3 nautical mile range. The Horizon line cargo ships 

try to limit graywater generation by using low-flow showers, faucets, and in the galley, since potable water is 

generated on the vessel using a distillation system. According to Mr. Becker, potable water generation on-board is 

expensive; therefore, limiting potable water use and subsequent graywater generation is a cost saving measure.