banner6a.jpg (17058 bytes)

Printer Version
6.5 in (17.1 cm) wide


A guide to Marine Sanitation Devices for recreational boat builders.

The following is mostly mine but has been contributed to by Peggie Hall, a specialist in Marine Sanitation Devices. Peggie has kindly offered advice and corrected my mistakes.

She is the author of "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and Other Sources of Aggravation and Odor"

Back in the 1970s Congress (see How Laws Are Made) directed the Environmental Protection Agency to write regulations for toilets on boats.  At the time this seemed to many people in the boating industry to be a bit of overkill considering how much impact a boat has on clean water as compared to a city like New York or Los Angeles, but the regulation came to be anyway. Of course the EPA was not the agency that would have to enforce these rules. That fell to the Coast Guard who had to write regulations for certifying Marine Sanitation Devices and who reluctantly began educating boat manufacturers and owners concerning requirements.

Basically it works this way. If you have a boat under 65 feet in length and you have a toilet on board it must be a portable device, or connected to a certified Type I or Type II device, or a Type III (a holding tank).

So what's the difference? The portable device is a small portable toilet that you can buy at any camping, RV, outdoor, or even hardware store. They usually hold around five gallons and will last a day or two depending on how many people use it, and you take it home and dump it in your bathroom toilet. You cannot dump them overboard. If you do, and you get caught, you will receive a hefty fine. They are commonly used on small day cruisers, overnighters, cuddy cabins, etc. 

A Type I is a device connected to a permanently installed toilet that treats the raw sewage until it is relatively clean and pumps it into the surrounding water. These are found on boats that do a lot of offshore cruising. The reality is that many areas of the USA are no discharge zones ( see link below to no-discharge zones) and so you can not discharge any waste, treated or otherwise. So the Type I becomes an option only if you do most of your boating in an area the allows discharge, or you are in international waters.

A type II is similar to a Type I but is designed to deal with much larger capacities of sewage.  The Type II output, the effluent, is treated to a much higher level than a Type I.  Typically Type II devices are found on much larger yachts and commercial vessels.  On a boat that is 65 feet in length or more you must have a certified Type II device or a Type III system.  Again a Type III is a holding tank and many larger boats, and even ships, that could use a TYPE II system have holding tanks instead, and hook up to the local sewer system when docked.

A type III is a permanently installed toilet connected to a holding tank that retains the sewage. When you return to the marina it is pumped into the local sewer system at a pump out station.  This is the most common system and most boats sold in USA, that have toilets, have a holding tank. The reality of this situation is that there is a serious lack of pump out stations. Many times the stations do not work, and marinas really do not want the expense of maintaining them. 

How do you know if a device is a Type I or II device? MSDs have to be US Coast Guard Certified. This means that they have to meet the requirements, and the manufacturer has to submit a request for certification to the Coast Guard. The Coast Guard has the device tested for compliance. If it passes, they send a letter of certification to the device manufacturer. The manufacturer then must attach a label to each device. There should be a certification label somewhere on the device.  If it doesn't have a label, assume it is not a certified device. A type III system is not required to be certified by the U. S. Coast Guard, and may have a label but is not required to have one.

Image showing the symbol for a pump out site. To find pump out facilities look for this symbol.

cvasym.gif (9277 bytes)

Type I MSD: A flow-through discharge device that, under the test conditions described in 33 CFR 159.121, produces effluent having a fecal coliform bacteria count no greater than 1000/100 milliliters, and no visible floating solids. A Type I MSD is commonly a physical / chemical type (macerator / chlorinator).

Type II MSD:A flow-through discharge device the, under the test conditions described in 33 CFR 159.121, produces effluent having a fecal coliform bacteria count no greater than 200/100 milliliters, and suspended solids no greater than 150 milligrams/liter. A Type II MSD is commonly a biological (aerobic digestion) plant, but several physical / chemical plants are certified as Type II MSDs.

Type III MSD: A device designed to prevent the overboard discharge of treated or untreated sewage, or any waste derived from sewage. Most Type IIIs are holding tanks, but there are also vacuum collection systems, incineration systems, recirculation systems, and a composting system.

Portable Toilets: portable toilets are not defined in the law. They are simply toilets you can pick up and carry off the boat. They are not permanently installed on the boat. Permanently installed is defined in many standards as meaning that tools must be used to remove the device.

In addition to the above, some really large vessels have incinerators to dispose of waste.

Regulations and links to the EPA.

The Marine Sanitation Device Regulations for Recreational Boats

EPA List of No Discharge Zones

Cornell Law School, The US Code on MSDs Code Of Fed Regs on Marine Sanitation Device Standard

Some Coast Guard And Law Enforcement Policies.

If you have a Type I or II MSD and are in a No Discharge Zone, the device must be locked so it cannot be accidentally or deliberately discharged.   This means you must have some sort of locking device on the through hull valve to keep it in the closed position.  Any lock will do. With some law enforcement agencies simply locking the door to the head will do but that is the rare case. Most look for a lock on the valve that allows it to discharge into the water, or removal of the valve handle. However, some boats have a combination of two or more switches that must all be pressed at the same time to activate the pump.  The Coast Guard Office Of Boating Safety has said this is legal on recreational boats (see USCG letter to US Marine). For more See 33 CFR 159.7 for Acceptable Ways to Secure a System

Here is an excerpt from Florida's boating regulations:

"Under federal law, if your boat has a valve allowing direct overboard discharge of untreated waste, it must be closed while operating in all inland and coastal waters. It is suggested you use a non-releasable wire tie, lock, or remove the valve handle to secure the device. When you are more than 3 miles offshore in the ocean, the valve may be open allowing direct discharge overboard.

A valve may also be found on boats having both a Type I or II and a holding tank. This gives the boater an option to discharge treated waste overboard or to contain it for pump out later. In certain waters, discharge of all sewage (whether Type I, II or III) is illegal."

Many boats with a holding tank, have a Y valve installed which allows the tank to be pumped out at a pump out station, or discharged directly overboard.  Inside US waters this valve must be locked!  Beware; many people think that all they have to do is go three miles offshore and they can dump the tank.   Under Federal regulations this is true, but some coastal states, such as Rhode Island, have passed laws extending this distance.  In Rhode Island it is nine miles.  

Almost all inland lakes and rivers are no discharge zones. Here I need to explain what this means. There are navigable waters and non-navigable waters. These are legal terms used to divide waters into those under Federal and State laws, and those that are controlled solely by the state or local authorities. For example, The Hudson River up to a point north of Albany NY, is a navigable waterway and is under both Federal and State laws.  Beyond that point it is non-navigable and controlled solely by the state. Clear Lake in California is sole state (or non-navigable water), while Lake Tahoe is a navigable waterway.  You need to ask the local authorities or your state Boating Law Administrator (see NASBLA) about the waters you plan to use. The best plan is to assume it is no-discharge until told otherwise by competent authority. So when I say inland lakes and rivers, I am speaking of non-navigable waters, that is those under state authority. Non-navigable does not mean they can not be used by boats.

There are exceptions. There are some navigable waters that are no-discharge zones. All of the waters of the state of Rhode Island are a No Discharge Zone. Many lakes that cross borders and are both Federal and State jurisdiction are no discharge zones.

I repeat, never assume an area is a discharge zone. Always assume it is a no discharge zone until you are informed otherwise by competent authority.

For Boat Builders: 

Recreational boat regulations and commercial vessel regulations are enforced in separate ways.  For recreational boats, the boat builder has the responsibility to insure that the boat meets the regulations that apply.  The Coast Guard does not routinely inspect recreational boats at the factory.  You may be visited by a representative (a contract employee) of the Coast Guard who will help you to comply with the laws. But it is your responsibility to certify that your boats comply with the law.

Many commercial vessels, especially passenger carrying vessels that carry more than six passengers, are inspected by the Coast Guard.  You must submit plans, have them approved, and undergo routine inspections during construction, and a final inspection.  All this is because it is the Coast Guard's responsibility to certify that these boats can safely carry passengers for hire. There may be additional requirements for the marine sanitation systems on commercial vessels.  Also some other commercial vessels that don't carry passengers, but are involved in coastwise trade, international trade and fishing, are inspected vessels.  You should contact the Coast Guard Marine Safety Center or the Marine Safety Office

in your area about this before starting construction.

Links to Information on Marine Sanitation Devices

BOATUS: Understanding MSDs
Ahead MSDs

National Assoc of State Boating Law Administrators Reference Guide to State boating Laws
Boating Laws In All States
Boating Basics On Line

Revised 04/05/2011 2011 All Rights Reserved