A marine sanitation device (MSD) is a piece of machinery or a mechanical system that is dedicated to treat, process, and/or store raw, untreated sewage that can accumulate onboard water vessels.
In the United States, the Environmental Protection Agency (EPA) sets performance standards for marine sanitation devices, and the U.S. Coast Guard (USCG) issues regulations governing the design, construction, certification, installation and operation of MSDs.
[3] Type I MSDs also rely heavily on chlorination and maceration to break down solids and kill any bacteria present.
It typically consists of a large storage tank that holds treated or untreated sewage that is held and released when the vessel returns to port.
[3] However, Type III MSDs can also consist of a holding tank with advanced technologies, including but not limited to incineration, recirculation, and composting.
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.
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.
The routine discharge of effluent incidental to the propulsion of vessels is explicitly exempted from the definition of dumping in the MPRSA.
[citation needed] The Act to Prevent Pollution from Ships (APPS) and its regulations implements U.S.-ratified provisions of MARPOL.
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.
[5] The purpose of the MSD is to treat the incoming blackwater and graywater that accumulates on board a floating vessel.
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.
Royal Caribbean International, for example, havsinstalled AWP systems on its ships which treat wastewater using advanced technology.
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.