Marine sanitation device

A Marine Sanitation Device, or commonly known as an “MSD” is a specific piece of machinery or system of machinery that is dedicated to treat, process, and/or store raw, untreated sewage that can accumulate onboard water vessels. It does not refer to portable devices such as portable toilets.

Variations of MSDs available

Currently, there are three kinds of Marine Sanitation Devices that are certified by the coast guard for use.

Type 1

This kind of Marine Sanitation Device has a flow through discharge setup. The sewage is broken down and processed through the use of chlorination and/or maceration. The bacteria count per one hundred milliliters of water must be less than one thousand. In a Type 1 MSD, there must be no evident floating solids.[1] Type 1 MSDs also rely heavily on chlorination and maceration to break down the bacteria present.[2]

Type 2

Similar to type 1, this Marine Sanitation Device is also a flow through discharge setup. However, the sewage is broken up through the use of aerobic bacteria or some other biological digestion process. The bacteria count found in one hundred milliliters of water produced from this system cannot be greater than two hundred.[1] Type 2 MSDs are usually reliant upon biological or aerobic digestion of bacteria present.[2]

Type 3

This kind of Marine Sanitation Device is very different compared to type 1 and type 2. This type is usually large storage tank that holds treated or untreated sewage that is held and deposited when the vessel returns to port. There, it is deposited onshore and treated accordingly.[1] However, type 3 Marine Sanitation Devices can also be incinerators or some form of recirculation plant. Ultimately, this kind of Marine Sanitation Device does not discharge its contents into the surrounding water. Instead, contents of a Type 3 Marine Sanitation Device are discharged into a holding tank or treated with advanced technologies including but not limited to incineration, recirculation, and composting.[2]

Laws and regulations

Under IMO, or International Maritime Organization, MARPOL 73/78, also known as the International Convention for the Prevention of Pollution From Ships ("Marpol" is short for marine pollution and 73/78 short for the years 1973 and 1978.) There are a total of six annexes that compose Marpol. Annex IV deals with the pollution of sewage by ships. In Annex IV, there are a total of 11 regulations regarding the laws and regulations surrounding sewage discharge and treatment plants on board. It wasn’t until the United States implemented Act to Prevent Pollution from Ships.[3]

33 CFR part 159

According to the United States Coast Guard, no vessel with a toilet on board may be operated unless there is a Coast Guard approved Marine Sanitation Device (MSD) aboard the vessel and fully functioning. These following regulations must be in compliance with 33 CFR part 159.[4] The purpose of 33 CFR part 159 is to comply with the Environmental Protection Agency under section 312 of the Federal Water Pollution Control Act which prohibits the discharge of untreated sewage into any body of waters of the United States. CFR 159 also has restrictions on vessels manufactures and vessels operators. Vessel manufacturers under CFR 159 may not sell, any vessel equipped with toilet facilities unless there is a) an operable Type II or Type III Marine Sanitation Device or b) an operable Type 1 device on a vessel that is less than 65 feet in length. Requirements for the vessel operator state that no person may operate the vessel unless a) an operable Type II or Type III Marine Sanitation Device or b) an operable Type 1 device on a vessel that is less than 65 feet in length and that if in a body of water where the discharge of untreated or treated sewage is prohibited by the Environmental Protection agency the vessel operator must secure the device.[3]

No Discharge Zones

Section 312 has another means of addressing sewage discharges, through establishment of no-discharge zones (NDZs) for vessel sewage. A state may completely prohibit the discharge of both treated and untreated sewage from all vessels with installed toilets into some or all waters over which it has jurisdiction (up to 3 miles (4.8 km) from land). To create a no-discharge zone to protect waters from sewage discharges by vessels, the state must apply to EPA under one of three categories.

  1. NDZ based on the need for greater environmental protection, and the state demonstrates that adequate pumpout facilities for safe and sanitary removal and treatment of sewage from all vessels are reasonably available. As of 2008, this category of designation has been used for 61 areas representing part or all of the waters of 26 states, including a number of inland states.
  2. NDZ for special waters found to have a particular environmental importance (e.g., to protect environmentally sensitive areas such as shellfish beds or coral reefs); it is not necessary for the state to show pumpout availability. This category of designation has been used twice (state waters within the Florida Keys National Marine Sanctuary and the Boundary Waters Canoe area of Minnesota).
  3. NDZ to prohibit the discharge of sewage into waters that are drinking water intake zones; it is not necessary for the state to show pumpout availability. This category of designation has been used to protect part of the Hudson River in New York.

Solid Waste

Ship discharges of solid waste are governed by two laws. Title I of the Marine Protection, Research, and Sanctuaries Act (MPRSA) applies to cruise ships and other vessels and makes it illegal to transport garbage from the United States for the purpose of dumping it into ocean waters without a permit or to dump any material transported from a location outside the United States into U.S. territorial seas or the contiguous zone (within 12 nautical miles (22 km) from shore) or ocean waters. Marine Protection, Research, and Sanctuaries Act. 33 U.S.C. § 1402-1421. EPA is responsible for issuing permits that regulate the disposal of materials at sea (except for dredged material disposal, for which the U.S. Army Corps of Engineers is responsible). Beyond waters that are under U.S. jurisdiction, no MPRSA permit is required for a ship to discharge solid waste. The routine discharge of effluent incidental to the propulsion of vessels is explicitly exempted from the definition of dumping in the MPRSA.

The Act to Prevent Pollution from Ships (APPS) and its regulations implements U.S.-ratified provisions of MARPO. APPS prohibits the discharge of all garbage within 3 nautical miles (5.6 km) of shore, certain types of garbage within 12 nautical miles (22 km) offshore, and plastic anywhere. It applies to all vessels, whether seagoing or not, regardless of flag, operating in U.S. navigable waters and the Exclusive Economic Zone (EEZ). It is administered by the Coast Guard, which carries out inspection programs to insure the adequacy of port facilities to receive offloaded solid waste.

History

After the Environmental Protection Agency issued certain regulation on January 29, 1976, regulations that are established today were upheld. Along with that, the Federal Water Pollution Control Act or also known as Clean Water Act, which was established in 1972, set the basis for regulations with regards to the Environmental Protection agency standards. Under section 312 of the Clean Water Act, the discharge of sewage from vessels must be controlled through the equipment which treats the sewage also known as Marine Sanitation Devices. Because of these regulations, certain states and the great lakes have established areas that are close to shore as no discharge zones. The reason in establishing regulations on marine sanitation devices is to prevent the spread of disease, keep the oxygen content in the sea at a healthy level, and to keep our ocean healthy in regards to appearance.[3]

Treatment

The purpose of the Marine Sanitation Device is to treat the incoming blackwater and graywater that accumulates on board a floating vessel. Graywater is water that drains directly from a shower, sink, or machinery located in the scullery. Normally, graywater is discharged directly overboard since it is not technically considered sewage and not damaging to the environment. However, in most ports around the world, discharge of fluids is strictly prohibited. To compensate for this situation, graywater piping is rerouted to the MSD. Blackwater is another word for sewage or human body wastes and wastes from toilets. According to the international maritime organization or the IMO, untreated sewage cannot be discharged overboard unless it is 12 nautical miles from the nearest land. Due to regulations issued by the IMO and the United States Maritime Administration or MARAD, every ship must have an approved marine sanitation device aboard their ship. Blackwater is therefore treated through a process that utilizes chlorination and/or biological treatment before being discharged overboard.[4]

Biological treatment

In type 2 Marine Sanitation Devices, sewage is broken down through the use of a natural biological component. Usually, this biological component is aerobic bacteria that occur in the media tank. Even though the sewage can have some aerobic bacteria naturally, a majority of the bacteria population is grown on mediums located within the media tank. Since aerobic bacteria require oxygen to live, some form of air pump is necessary to provide sufficient oxygen for the bacteria. This air pump can be a fan or roots blower connected to the tank. By providing sufficient air, most of the smell caused by sewage and anaerobic bacteria is eliminated.[5]

Chlorination and maceration

In type 1 Marine Sanitation Devices, sewage is broken down usually through the use of chlorination and/ or maceration. The chlorination process is usually done within a large tank sometimes referred to as the contact chamber. By adding chlorine to the sewage, the effluent is sanitized and it is discharged from the MSD. The maceration process aboard ships is usually done using some form of machinery to crush and pulverize the incoming sewage. However, since a large portion of bacteria is still present in the macerated sewage, the sewage is considered untreated still. Due to this circumstance, maceration machinery is usually paired with some form of chlorination process in the same system. Very few places around the world allow the discharge of untreated sewage from a maceration process.[6]

Advanced water treatments

Sometimes, certain water vessels are equipped with advanced water treatment plants instead of traditional Marine Sanitation Device’s. Advance Water Treatment plants can also be referred to as Advanced Wastewater Purification (AWP) systems. They are most commonly found on ships that sail in Alaskan waters and sometimes work in parallel with an onboard Marine Sanitation Device. Royal Caribbean International, for example, have installed AWP systems on their ships which treat wastewater using advanced technology. Royal Caribbean AWP systems include three types of water purification systems, Scanship, Hydroxyl/Headworks and Navalis. Scanship and Hydroxyl use biological treatment while the Navalis system primarily uses advanced oxidation and filtration methods. Scanship and Hydroxyl systems use bacterial to consume the waste while also utilizing a chemical in order to break down and remove solids. Scanship and Hydroxyl systems are very similar to water treatment plants based on shore. This involves a simple five stage process. The first stage involves a prefilter where screens removes heavy and noticeable solids from the waste influent. Then the wastewater is passed through a biological reactor which uses beneficial bacteria to further break down any solids. Next the influent is pumped through a flotation unit which removes floatable waste. Afterwards, the clean water is passed through polishing filters which make the water even cleaner. The last and final stage involves an ultraviolet light reactor which disinfects the water. The final product may then be dried, incinerated, stored, or discharged at sea with respect to international regulations.

The Navalis AWP system utilizes a seven-stage process in order to treat wastewater. [7] The first stage involves wastewater entering the shaker screens which removes any noticeable solids. Then the wastewater is passed through an AET Roughing Reactor which help with chemical equalization and load. Then the influent is treated by a three-stage particle removal process which involve chemical flocculation, Hydraulic Separation, Tubular Filtration, and Ultra Filtration membranes. The waste influent is then passed through Oxidation Reactors which serve to oxidize pollutants and aid the production of carbon dioxide gas and water. The seventh and final stage consists of a powerful Ultraviolet Reactor in which the ozonated water is broken down into oxygen compounds that provide further treatment of the water. The leftover solids are then oxidized which provide safe bio-disposal or land based discharge if needed.[3]

References

  1. 1 2 3 Marine Sanitation Device. (n.d.). Retrieved March 23, 2015, from http://www.uscg.mil/hq/cg5/cg5213/msd.asp
  2. 1 2 3 McLemore, A. (2011). The engineering cruise notebook: A study guide for the engineering students of the Training Ship Golden Bear. Vallejo, CA.
  3. 1 2 3 4 Annex IV of MARPOL 73/78 Regulations for the Prevention of Pollution by Sewage from Ships. (n.d.). Retrieved April 8, 2015, from http://www.mpa.gov.sg/sites/circulars_and_notices/pdfs/shipping_circulars/mc03-18a.pdf
  4. 1 2 33 CFR Part 159 - MARINE SANITATION DEVICES. (2008, June 19). Retrieved March 23, 2015, from https://www.law.cornell.edu/cfr/text/33/part-159
  5. ↑ Dasch, E. (2003). Water: Science and issues. New York: Macmillan Reference USA.
  6. ↑ Federal Marine Sanitation Device Regulations. (n.d.). Retrieved March 23, 2015, from http://www.dbw.ca.gov/pubs/FedMSD/index.htm
  7. ↑ Advanced Wastewater Purification Systems. (2012, July 12). Retrieved April 6, 2015, from http://www.royalcaribbean.com/content/en_US/pdf/RCI_wastewater_pur.pdf
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