2020 Boat Sewage Regulations: What Boat Owners Need to Know



Boat owners or rig operators are sternly regulated in regard to the way that they dispose of their boat sewage. There are many good reasons for this. For one, you want to make sure that you’re keeping the environment around your boat safe, for the good of everyone (including yourself).

In order to ensure that everyone in U.S. national waters follows the same rules, the U.S. Coast Guard issues a set of regulations for marine waste discharge. The International Maritime Organization (IMO) and the Environmental Protection Agency (EPA) also have comprehensive, easily accessible information to ensure that everyone knows how to make the sea a safe place for everyone to be

What are these 2020 boat sewage regulations? What can happen if you aren’t in compliance—and what do you need to do to ensure that you aren’t going to get slapped with any hefty fines? We’ll cover all of this and more in this handy guide.

What Will Happen If I Don’t Follow IMO and Coast Guard Regulations for Boat Sewage Discharge? 

According to the IMO, improperly discharged boat sewage can lead to oxygen depletion, which can result in issues for marine life. It can also create obvious visual pollution, which, in many coastal areas, may constitute a large problem for countries that thrive on the tourism industry. 

Therefore, to avoid fines, improper polluting, and causing economic or personal harm to those around us, it’s important to know and adhere to these boat sewage regulations. In addition, taking the time to make sure your boat is up to code for all things sewage will likely result in a more smoothly functioning vessel.

What are the main 2020 boat sewage regulations? 

To help keep shared water safe, it’s against federal law to discharge any sewage that you haven’t safely treated. This applies to any vessel that’s in U.S. navigable waters. The EPA notes a few further rules that you need to keep in mind:

The Clean Water Act requires that your vessel must have a Coast Guard-certified marine sanitation device (MSD) on board. That MSD needs to have a properly working and properly installed toilet. 

  1. It’s prohibited to discharge untreated sewage within three miles from shore. 

  2. Within three miles from shore, all boat sewage needs to be treated by a Type I or Type II MSD. Beyond three miles, all sewage needs to be stored in a holding tank—or a Type III MSD. 

  3. Boat sewage discharge, treated or untreated, is prohibited in freshwater lakes and reservoirs, rivers that can’t be navigated by interstate vessel traffic, and no-discharge zones (NDZs). 

These are the main boat sewage regulations in 2020. It’s a good idea to follow the Coast Guard, IMO, and EPA for any updates, just to make sure that you’re covered at all times. 

Why is the limit three miles from shore for any untreated boat sewage disposal? 

The IMO states in Annex IV of MARPOL, or the International Convention for the Prevention of Pollution from Ships, that the movement of the high seas is capable of taking care of raw sewage. This is partially due to the higher levels of bacterial action that exist further out at sea. 

The three-mile distance from shore has been deemed to be a conservative measure by regulating authorities. If you’re in any doubt as to whether you’re able to discharge your waste in a certain area, it’s best to hold on until you’re completely sure that you’re in a licit discharge zone. 

What boat sewage waste is regulated by the IMO? 

According to the IMO’s rules regarding boat sewage discharge, there are two different types of waste: blackwater and graywater

Blackwater is likely what you’re thinking of when you think of boat sewage. MARPOL Annex IV covers the following types of blackwater waste: 

  1. Drainage waste, or all waste collected from urinals and toilets aboard your vessel

  2. Any waste drained from a sick bay, a medical dispensary, washtubs, washbasins, or similar locations on your rig or vessel

  3. Any drainage from any cargo holds that contain living animals

  4. Any wastewater that might be mixed with any drainages of spaces such as those listed above

These types of waste must be treated before being discharged, and they cannot be discharged at all in certain NDZs. 

Can I dump graywater off my vessel? 

Gray water is leftover or untreated water, a result of domestic or on-board processes. The EPA refers to the Vessel Incidental Discharge Act for all graywater inquiries regarding commercial boats. (There are no regulations concerning gray water for personal or recreational crafts.) 

Typically, you’ll need to find out whether the graywater you intend to discharge is mixed with sewage effluent or not. If it is, then you might face restrictions. If it’s not, then you’re likely able to discharge it safely. 

Are there regulations surrounding which type of marine sanitation device I can have? 

It’s required for you to have operable, Coast Guard-certified MSDs on board vessels with installed toilets, so long as they are operating in U.S. waters. Fortunately, there’s a quick way to tell whether your marine sanitation device is certified. The U.S. Coast Guard states that if your unit was made after January 1976, it’ll have a label on it that designates it as Coast Guard certified. 

There is an exception: If you have a Type III, or no-discharge, MSD, your system might be Coast Guard certified by definition—so you won’t have a label designating it as such. However, if you have a Type I or Type II flow-through MSD, checking for that Coast Guard certification label is a quick way to confirm it. 

What do I need to know about no-discharge zones?

The EPA says that no-discharge zones are, ultimately, exactly what they sound like. An NDZ is an area in which you cannot discharge any sewage from your vessel, whether it’s been properly treated or not. If you’re going through an NDZ, you need to keep all of your sewage discharge on board until you leave the NDZ behind. 

If you have a Type I or Type II flow-through MSD, you’ll need to make sure that it’s fully secured and closed while you’re going through an NDZ. This is just to make sure that you don’t discharge any boat sewage unintentionally, to protect both yourself and the surrounding environment. Depending on the type of MSD you have, you might need to close or padlock the sea cock, or lock the door to the room containing your toilet space. 

Once you leave the NDZ behind, you’ll be able to treat and discharge any waste you may have accrued. 

Is there anything I need to know about chemicals I can safely and legally use to treat my boat sewage? 

Fortunately, this one’s simple. First of all, the EPA realizes that not all MSDs require chemicals, especially holding-tank models such as Type III MSDs. If you do have a model that requires chemical maintenance, there’s a good chance that those chemicals will be primarily chlorine-based. As long as you’re working with a Coast Guard-certified MSD and you’re dosing the system with the right chlorine type as recommended by the manufacturer, your chemical usage should be fine. 

Following the rules and regulations provided by the Coast Guard, the EPA, and the IMO can seem like too much to deal with at times. However, it’s best to remember that the rules are there for a reason. They can seem like a hassle, but they’ve been put in place to keep everyone safe.

At the very least, it’s a good idea to ensure that your MSD is Coast Guard certified and your boat sewage discharging systems are up to date and up to code because it’ll give you some peace of mind. Not having to worry about any Coast Guard fines should be worth a little extra preparation and maintenance on your part.

Call H2O LLC for Any Questions You Have Regarding 2020 Boat Sewage Regulations

For any questions you may have regarding Coast Guard regulations and other expectations regarding your marine sanitation practices, or for an assessment of how your MSDs are performing, you can always turn to H2O LLC for helpful advice. For high-quality water treatment systems and marine sanitation devices as well as the reliable on-site support you need, call H2O LLC whenever you need efficient expertise at hand.