The Ultimate Guide To Replacing Boat Waste Systems

Sewage management is an important but often overlooked aspect of boat ownership. To keep our waterways clean and safe for everyone, it is crucial to understand how to properly manage and dispose of sewage when boating. This includes knowing the different types of sanitation systems available, such as marine sanitation devices (MSDs), and the regulations surrounding their use and maintenance. In this article, we will discuss the process of replacing the waste system on a boat, covering everything from selecting the right system for your boat to understanding the legal requirements for sewage disposal.

Understanding the different types of Marine Sanitation Devices (MSDs)

Marine Sanitation Devices (MSDs) are crucial for the safe and enjoyable functioning of your boat. The wrong MSD can lead to overloaded systems, Coast Guard fines, frustrating maintenance projects, and high replacement costs.

The US Coast Guard categorizes MSDs into three types:

Type I

Type I MSDs are on-board flow-through treatment devices that use a physical/chemical-based system. Sewage is macerated and chlorinated, and then discharged from the vessel. This type of MSD is typically found on smaller recreational boats that are 65 feet in length or shorter. The treated waste must meet Coast Guard standards, with a fecal coliform bacterial count of no greater than 1000 per 100 milliliters and no visible floating solids.

Type II

Type II MSDs are also on-board flow-through treatment devices but they use a biological or aerobic digestion-based system. This type of MSD is more commonly found on large commercial vessels. The treated waste has a lower bacterial count than Type I, with a fecal coliform bacterial count of no greater than 200 per 100 milliliters and total suspended solids of no more than 150 milligrams per liter.

Type III

Type III MSDs are the simplest of the three types, consisting of a holding tank that prevents the discharge of treated or untreated sewage overboard. These MSDs are typically found on smaller recreational boats and may include additional technologies such as incineration, recirculation, and composting. While Type III MSDs are less complex, they are also less effective at treating waste.

It is important to note that discharging untreated sewage from a boat is illegal in many areas, and there are also restrictions on discharging treated sewage in certain zones.

How to empty your holding tank offshore

Emptying your boat's holding tank offshore is a two-step process. Firstly, you must travel at least three miles offshore—this is a legal requirement. Secondly, you need to empty the tank. There are three methods for doing this: a gravity-fed system, an electric macerator system, and a hand pump-out system.

Gravity-Fed System

If you have a gravity-fed system, the process is simple. Open the valve and listen for the sound of waste emptying from the boat, then close the valve once done.

Electric Macerator System

For an electric macerator set-up, you will need to open the macerator line's thru-hull fitting in the bilge or lazarette so that fluids can exit the boat. On your electrical panel, there may be two buttons: one to switch the power on and off, and another that must be held in position (like a drill trigger) to activate the pump. Turn on the power to the pump, then hold down the macerator button. You'll know the tank is empty when you hear the motor begin to free wheel and spin.

Hand Pump-Out System

With a hand pump-out system, you must still open the holding tank thru-hall valve. Then, simply pump until the waste runs clear. It may take some priming at the beginning to get things started.

Regardless of the method used, be sure to close the thru-hull valve when finished. Also, remember that it is illegal to discharge untreated sewage within three miles of the shore.

How to empty your holding tank at a pump-out station

Emptying your boat's holding tank at a pump-out station is a straightforward process. Here's a step-by-step guide on how to do it:

Step 1: Locate the Waste Cap

Before you begin, make sure you correctly identify the waste cap on your boat. It's important not to mix it up with the fuel or water caps as these fluids should not be mingled. Once you're sure you have the right cap, remove it. There might not be a chain holding it to the deck plate because it needs to be completely removed for the exit line tube to be inserted.

Step 2: Prepare the Pumpout Hose

Put on gloves for sanitation and safety. You can find inexpensive disposable nitrile or latex gloves at marine supply stores or hardware stores. Locate the waste fitting to which your pumpout hose connects. These fittings are usually sealed with keyed plates, so you'll need a special tool to open them. Spin the waste fitting cap off and set it aside in a secure place. Read the instructions on the pump to familiarise yourself with its operation.

Step 3: Connect the Hose

Ensure that the valve on the nozzle of the shoreside pumpout hose is turned to "off" and that it fits your deck through-hull. If it doesn't fit, you may need an adapter, which is usually available at the pumpout station. Connect the hose to the deck fitting.

Step 4: Start the Pumpout

Typically, you'll press a switch to activate the shoreside pumpout. With the pump running, place the rubber-ended nozzle into the deck fitting and slowly open the valve. If the hose has a sight glass, you'll be able to see the wastewater being pumped out. If not, you'll hear a sucking sound when the process starts and when the tank is empty.

Step 5: Complete the Pumpout

Once the pumpout is complete, keep the pump running to ensure all wastewater is removed from the hose. Then, close the valve. You may want to flush some freshwater through the head and pump it out as well to ensure everything is clean.

Additional Tips:

• If there's a bucket of water or a disinfectant mixture at the pumpout station, use it to disinfect the pumpout hose. Open the nozzle valve, place the nozzle in the liquid, allow it to draw some, and then turn off the nozzle.
• Some pumpout stations don't have an "off" switch; these are either on a timer or will automatically shut off when they sense that they're no longer pumping wastewater.
• If the pumpout machine isn't working or isn't creating enough suction, report it to the marina operator and wait for assistance or move to another marina.
• Regularly pump out your holding tank to ensure it always has room and to avoid the inconvenience of a full tank.
• Know the location of the nearest pumpout station.

How to prevent accidental discharge

To prevent accidental discharge when replacing your boat's waste system, follow these steps and general guidelines:

First, it is important to understand the different types of Marine Sanitation Devices (MSDs) and their discharge criteria. Type I MSDs are flow-through discharge devices that use physical or chemical-based systems, typically maceration and chlorination, and can be used on vessels below 65 feet. Type II MSDs are also flow-through discharge devices, but they use aerobic digestion-based systems and are often found on commercial vessels. Type III MSDs are holding tanks that prevent the discharge of treated or untreated sewage and can be used on all types of vessels. Make sure your MSD meets the requirements set by the U.S. Coast Guard and is certified accordingly.

To prevent accidental discharge, the "Y" valve, which is installed between the toilet and the MSD, must be secured. This can be done by using a lock or non-reusable seal on the "Y" valve, or by removing the handle. This blocking mechanism will prevent accidental illegal discharge of sewage.

Additionally, always use shoreside restrooms when docked or before casting off. When emptying your holding tank, you have two options: travel at least three miles offshore or go to a fuel dock with a waste pump-out facility. If you choose to pump out at a station, locate your waste cap and make sure not to mix it up with fuel or water caps. Completely remove the waste cap to insert the exit line tube. Follow the facility's instructions for pump-out, and consider pumping freshwater through the head afterward to ensure a thorough emptying of the tank.

Remember, it is illegal to discharge untreated sewage from a boat on any inland waters and within three miles of the shore in coastal waters. Always follow local regulations and guidelines to prevent accidental discharge and minimize environmental impact.

How to maintain your MSD

Maintaining your marine sanitation device (MSD) is an important but manageable task. Here are some detailed instructions on how to maintain your MSD:

Understanding Your MSD

First, it's important to understand the different types of MSDs and how they work. There are three types of MSDs: Type I, Type II, and Type III. Type I and Type II MSDs are treatment devices that use physical, chemical, or biological processes to treat sewage before discharging it overboard. Type III MSDs, on the other hand, are holding tanks that store sewage until it can be pumped out at a pump-out station.

Regular Pumpouts

Regardless of the type of MSD you have, regular pumpouts are essential. Find a pump-out station and follow the instructions provided to empty your holding tank. This will ensure that your tank always has room and prevent overflows. It is also a good idea to know the location of the nearest pump-out station in advance. Remember that it is illegal to discharge untreated sewage into inland waters and within three miles of the shore.

Proper Use and Maintenance

Always use the correct waste cap when emptying your holding tank to avoid mixing it with fuel or water. If you have a Type I or Type II MSD, ensure it meets Coast Guard requirements by looking for a certification label. For Type III MSDs, periodically rinse the entire system with water and use a vinegar solution to reduce scale buildup and keep the hoses clean. Deodorize the boat's head with a mix of borax and water, and sprinkle baking soda around the rim.

Troubleshooting and Replacement

If your MSD develops a horrid smell, consider adding a charcoal filter to the vent line. If the incoming water stinks when you flush, it could be due to anaerobic bacterial growth. Pumping vinegar through the system and leaving it in the hoses instead of saltwater when not in use for extended periods can help. If your MSD malfunctions or clogs, you may need to replace certain components, such as Y-valves, macerators, or even the entire system.

Environmental Impact

Remember that the primary concern with sewage is its environmental impact. Untreated sewage can have detrimental effects on aquatic life and human health. By properly maintaining your MSD and following the regulations, you can do your part to protect the environment and ensure a pleasant boating experience for everyone.

Frequently asked questions