How to Size Your Marine Wastewater System


Marine CZ three _side view

While you’re spending time on your offshore vessel, it’s important to ensure that you can enjoy a safe, sanitary life at sea. For both your guests and your crew, this includes simply and effectively getting rid of the waste your personnel produces on a daily basis. 

Not only is this crucial for a pleasant atmosphere on your vessel, but it’s also required in regulations set forth by the International Marine Organization (IMO) and the United States Coast Guard. Failing to have a smoothly running wastewater system can net you serious fines, as well as an unhealthy environment for everyone aboard your vessel. 

Fortunately, there’s a simple way to ensure that your vessel’s waste management system is always taken care of. With a correctly sized marine wastewater system, you’ll be able to make sure your boat is safe in no time at all.

The Importance of Correctly Sizing and Maintaining Your Marine Wastewater System

Your vessel’s marine wastewater system consists of sanitation devices and other pieces of equipment designed to collect, process, treat, and get rid of the sewage your vessel collects. Your system should do this in an efficient way that meets all regulations and enables multiday excursions at sea. 

Properly working marine wastewater systems are also crucial for environmental reasons. Treated waste won’t adversely affect the underwater ecosystems located near your boat. If you skip the treatment process, the waste your vessel produces could be toxic for the surrounding natural life. 

Your marine wastewater system is vital for your vessel. However, it isn’t the most pleasant system to maintain. You definitely don’t want your marine sanitation device to break. After all, what’s the alternative? Hands-on management of sewage? That’s neither fun nor safe. 

Maintenance of these devices can take a lot of work. There is, however, a way to make maintaining your system easier: by making sure that your device is never overloaded.

Why Overloading Your Marine Wastewater System Could Cause Problems

If your marine wastewater system is too small, you risk overloading (or surging) your marine sanitation device with more waste than it can handle. If this happens, you’ll shortly experience a foul odor permeating your vessel. Your system won’t have the capacity to treat the incoming sewage fast enough—and you’ll be able to tell. 

As a result of overloading your wastewater system, you risk having large amounts of toxic sludge sitting in your system for long stretches of time. These backup stacks can make it hard for the functional bacteria to process all of the waste. Next, your system will get blocked. After a while, this pressure buildup may break your system

For your health and happiness—as well as the safety of everyone on board your vessel—it’s important that this does not happen.

An unhealthy environment isn’t the only risk you face with an overloaded system. The costs associated with system repairs and replacements can be extensive. If you need to have an expert come in and fix the problem, that will cost a lot of money. If you end up having to replace the wastewater system, that will cost even more.

Not overloading your marine sanitation device is the most important thing you can do to avoid breaking your system. If you’re planning on replacing your marine wastewater system, it’s likely a good idea to take advantage of that fact. Ensure that your new sanitation device is properly sized for your vessel. This will protect your investment and make maintenance easier. 

We’ll go over the exact way to do just that in the next section.

Steps to Take to Properly Size Your Marine Sanitation Device

We’ve made it clear: Choosing the right size for your wastewater system is crucial for easy maintenance and a healthy environment on your boat.

When you’re trying to purchase a new system, however, it can be far from easy to tell which size is right for your circumstances. A first glance at the different sizes of sanitation systems can leave you confused. Without knowing it, you could easily purchase the system, leaving yourself open for difficult maintenance and frustrating fixes in the future. 

Instead, take some time before you invest to ensure that you’re sizing your system for optimal success.

1. Start by estimating the number of people you will regularly have aboard your vessel. 

This includes the crew, maintenance, and any visitors or guests. If you’re in doubt, it’s a good idea to round up in order to account for any unexpected situations. 

Why is this important? Your marine wastewater system has to support the needs of a set number of people per day. Because of this, you should use accurate data about your vessel’s population to size your system. In the future, you can also use the limitations of your wastewater system to inform recommendations for the number of people allowed on your boat. 

2. Think about the amount of time that you (and the majority of the people on board) will be using your craft for. 

Again, round up. This also provides valuable information: whether you will have 24-hr operation on your offshore platform or if you will be routinely going on multiday excursions, you need to be able to plan for that without a waste-related catastrophe. If, on the other hand, you use your vessel for only a few hours daily, you may be able to use a smaller system. 

It’s a good idea to think ahead when you make this assessment. Will there be seasons or years in the future when you use your vessel for longer periods of time? If so, select that longer time period now. You’ll be glad you did when the size of your wastewater system isn’t a constraint that dictates future plans

3. Consider the official maritime regulations you will need to observe..

Which certification will your system require? Depending on which waters your vessel will operate in, you will need to meet certain maritime regulations. For example, those set by U.S. Coast Guard or IMO? Each regulating body has different guidelines on amount of waste produced by an individual. The guidelines are used in calculating the correct unit size. Do a little research and find which set of regulations you will be expected to follow

The high standards set by the U.S. Coast Guard and the IMO will influence which type of marine wastewater system is best for you. Taking the time to make sure that any other locales in which you frequently work or spend time have similar regulations will likely save you headaches in the future. 

4. Finally, what type of load will you be introducing to your marine wastewater system?

Consider the specific types of waste that your system will have to process. This may include:

  • Blackwater: any waste from marine toilets or urinals 
  • Gray water: any water that has been used for laundering, washing, bathing, or showering
  • Washing machine fluids
  • Dishwater runoff
  • Kitchen waste
  • And more

Be as comprehensive as you can. Different marine sanitation systems may have differing capabilities to handle the types of sewage the people on your boat regularly produce. For example, if you’re planning on using the cooking area in your vessel more often in the future, make sure to consider that when you’re concluding your assessment. 

The answers to these questions will guide you to a marine wastewater system that will be properly sized for your craft. As a rule of thumb, it’s better to size up when possible. Ultimately, the more people you have on your vessel, the larger your marine wastewater system will have to be. Having a little extra room may come in handy if you try to expand your business in the future

If you’re interested in finding out which size is best for you, check out H2O’s wastewater system sizing calculator. It’ll run all of your specifications through a behind-the-scenes algorithm to help you find precisely the size you need for your system.

Whether you’re interested in pricing a reliable marine wastewater system, you’re in need of assistance with the maintenance of your sanitation device, or you’re just looking for trustworthy support for your vessel or offshore platform, turn to H2O LLC. For years, H2O has provided top-tier water treatment systems to the offshore oil and gas and marine markets. With a correctly sized wastewater management device, you’ll know for sure that your vessel will be safe and healthy for years to come.