Disclaimer: I am not a spokesperson for
the US Coast Guard or ABYC. For an official interpretation of regulations or standards you must contact the US Coast Guard or
other organization referenced..
MARINE SANITATION DEVICES
(Marine Toilets) USA only
The following is mostly mine but has
been contributed to by Peggie Hall, a specialist in Marine Sanitation
Devices. Peggie has kindly corrected my mistakes.
Author "Get Rid of Boat Odors - A Guide To Marine Sanitation Systems and Other Sources of Aggravation and Odor"
Peggie can be found on many other
on-line boating sources such as:
Community on MSDs
The Boat Yard
There is no law in the USA that says you have to have a toilet on a boat, except of
course the law of nature, or maybe your wife; but if you do have a toilet there are laws
regulating what kinds of toilet systems you must have.
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 regulation 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
So what's the difference? The portable device is a small
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
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.
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
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.
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.
Marine Sanitation Device Regulations for Recreational Boats a pdf file.
of No Discharge Zones
Cornell Law School,
The US Code on MSDs
Justia.com 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 assumme 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. This does not mean they can not be used by boats.
All of the waters of the state of Rhode Island are a No Discharge Zone.
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 these
boats. There may be additional requirements for the marine sanitation
systems on commercial 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 on MSDs
Links to state laws on MSds
National Assoc of State Boating Law
Administrators Reference Guide to State boating Laws
Boating Basics On Line