Docked Boat Septic Disposal: How To Do It Right

Septic waste on docked boats is a serious issue, with a single toilet flush of untreated sewage from a boat causing the same environmental impact as 10,000 flushes from a home toilet. This is because raw sewage contains excess nutrients that contribute to harmful algal blooms, use up oxygen, and contaminate shellfish beds with pathogens. To combat this, boat owners must follow strict regulations and employ proper waste management strategies. These include using onshore facilities when docked, installing Marine Sanitation Devices (MSDs), and understanding No Discharge Zones (NDZs). MSDs come in three types: Type I and II treat waste and discharge it overboard, while Type III stores waste in a holding tank for onshore pump-out or offshore discharge. NDZs prohibit the discharge of any sewage, treated or untreated, to protect aquatic habitats, species, and drinking water sources.

Blackwater tanks

There are laws and regulations surrounding the proper handling and disposal of waste from blackwater tanks aboard marine vessels. It is illegal to discharge untreated sewage within three miles of the coastal shore and within all inland waters, such as lakes and rivers. In designated No Discharge Zones, it is prohibited to discharge any sewage, treated or untreated, into the water. These zones are marked on NOAA charts and can also be found on the EPA's list of No Discharge Zones.

To comply with these regulations, boats must be equipped with an on-board treatment device or a holding tank. Treatment devices can be of Type I or Type II, which treat the waste and discharge it overboard, reducing bacteria but not nutrients. Holding tanks, also known as Type III MSDs, store the waste and require it to be pumped out at a shore-based facility or discharged offshore beyond three miles from the coast.

Proper maintenance of blackwater tanks is crucial to prevent odours and ensure the system's functionality. This includes regular pumping, flushing, and occasional treatments. Pumping should be done when the tank is no more than 2/3 full or when there is an unpleasant odour. Flushing involves pumping the tank dry, filling it with freshwater, and pumping again to remove any remaining solid wastes. Enzyme and nitrate additives can be used as treatments to promote tank cleanliness, reduce odours, and break down wastes.

It is important to use only bathroom toilet paper designed for marine use, RVs, or septic tanks, as it breaks down quickly and helps prevent clogs. Nothing other than human waste should be flushed down the head, as food, personal care items, or hygiene products can cause clogs and lead to costly repairs.

Pumping out septic tanks

Pumping out a septic tank on a docked boat is a necessary but unpleasant task. It is important to do this regularly to avoid a build-up of waste, which can cause unpleasant odours and even damage your boat.

How to Know When to Pump

If your boat's living quarters or restroom has an unpleasant or lingering smell, this is a good indication that it's time to pump your holding tank. You should also look out for the tank gauge to indicate that the tank is no more than two-thirds full.

The Pumping Process

The process of pumping out is fairly straightforward and usually involves the following steps:

• Open the boat's on-deck discharge port.
• Connect the service pump plumbing to the boat fitting.
• Open any valves, if present.
• Turn on the pump.
• Pump until the sight glass pumps clear.
• Clean, return and/or shut off the service pump.
• Ensure your boat's deck fitting is capped and valves are closed.

Flushing

After pumping, it is recommended to flush the tank. First, pump the tank dry, then fill it with freshwater and re-pump. This helps to further break up and remove any solid wastes left behind. This process may need to be repeated multiple times.

Troubleshooting

Sometimes, problems can arise during pumping and maintenance. Here are some common issues and their solutions:

• Loss or insufficient suction: This could be due to a pump priming problem or a bad pump diaphragm. Ask for help from the pump station owner.
• Tank contents not being removed: This could be due to a clogged outlet plumbing or a clogged tank vent line. Try using a plumber's snake to fix the issue.
• Sludge remains after flushing: Fill the holding tank with clean water and agitate the water by chopping the boat. If this doesn't work, add a small amount of liquid detergent and repeat the process.

Important Considerations

• Do not use drain cleaners: Drain cleaners can increase the buildup of scale within the tank and damage plumbing components.
• Use freshwater to flush: Using seawater can react with chemicals in human waste, leading to scale deposits that are difficult to remove.
• Use appropriate toilet paper: Always use toilet paper designed for marine vessels, RVs, or septic tanks. These types break down more quickly and reduce the risk of clogs.
• Do not flush anything other than waste: Even biodegradable items can cause clogs in the plumbing, leading to costly fixes.

By following these steps and considerations, you can effectively pump out and maintain your boat's septic tank, ensuring a pleasant and odour-free experience for you and your shipmates.

Marine Sanitation Devices (MSDs)

There are three types of MSDs, each with its own design, certification, and discharge criteria:

Type I MSD

A Type I MSD is a flow-through discharge device that treats waste and discharges it overboard. It produces an effluent with a fecal coliform bacteria count of not greater than 1,000 per 100 milliliters and no visible floating solids. This type of device typically relies on maceration and chlorination and is issued a Certificate of Approval. The cost of installing a Type I MSD is typically $1200 or more.

Type II MSD

A Type II MSD is also a flow-through discharge device, but it treats waste more effectively than Type I and discharges it overboard. It produces an effluent with a fecal coliform bacteria count of not greater than 200 per 100 milliliters and suspended solids of not more than 150 milligrams per liter. This type of device is typically found on larger boats due to its electricity and space requirements. The cost of installing a Type II MSD is usually $4000 or more.

Type III MSD

A Type III MSD, also known as a holding tank, prevents the discharge of treated or untreated sewage. It stores the waste to be pumped out at a shore-based facility or discharged overboard when more than 3 miles offshore in the ocean. A Type III MSD is a good option for boats that rely on onshore pump-out facilities or plan to discharge overboard in approved areas. The cost of installing a Type III MSD is around $500 or more.

It is important to note that the use of MSDs and the discharge of sewage are subject to regulations and may vary by region. In some areas, such as No Discharge Zones (NDZs), the discharge of treated sewage is prohibited. Boat operators must retain their sewage discharges on board for disposal at sea or onshore at a pump-out facility. Additionally, the use of certain chemicals in MSDs can impact aquatic life, so it is recommended to use enzyme and bio-active treatments whenever possible.

No Discharge Zones (NDZs)

Within an NDZ, vessel operators are required to retain their sewage discharges onboard and dispose of them at onshore pump-out facilities or discharge them beyond three miles from the shore. This means that boats must store their sewage and cannot release it into the zone, even if it has been treated.

There are currently 91 NDZs across 27 states in the United States, and these zones are clearly marked on NOAA charts and listed on the EPA's website. It is important for boaters to be aware of the locations of NDZs and to comply with the regulations to protect the environment and human health.

NDZs are established to protect aquatic habitats, drinking water intake zones, and special aquatic habitats or species. The EPA, in collaboration with state officials, determines the need for greater environmental protection and the availability of adequate pump-out facilities before designating an NDZ.

To comply with NDZ requirements, vessel operators must follow specific methods to secure their marine sanitation devices (MSDs). For Type I and Type II MSDs, this includes closing and securing the seacock, while for Type III devices, it involves closing valves leading to overboard discharge.

The establishment of NDZs is a crucial step in reducing the environmental and human health impacts of boat sewage. By prohibiting the discharge of sewage, NDZs help maintain water quality, protect sensitive ecosystems, and ensure safe recreational activities.

Pumpout stations

Location and Identification

Usage and Process

The process of using a pumpout station is straightforward. It involves opening the boat's on-deck discharge port, connecting the service pump plumbing to the boat fitting, opening any valves, turning on the pump, and pumping until the waste is cleared. It is important to follow the posted instructions at the pumpout station for effective and proper disposal. After pumping, it is necessary to clean and return or shut off the service pump and ensure the boat's deck fitting is capped, and all valves are closed.

Environmental Impact

The use of pumpout stations is crucial for minimizing the environmental impact of boat sewage. Untreated sewage from boats can have a significant ecological footprint, with a single flush of untreated sewage potentially causing as much damage as 10,000 flushes from a home toilet connected to a sewage treatment facility. Boat sewage contributes to harmful algal blooms, reduces dissolved oxygen levels, and contaminates shellfish beds with pathogens. Therefore, proper disposal at pumpout stations is essential for preserving aquatic ecosystems and human health.

Waste Management Options

Boaters have several options for managing their sewage, depending on their boat's setup and location. Some boats are equipped with installed toilets, which, by law, must be connected to a Marine Sanitation Device (MSD). There are three types of MSDs: Type I, which treats waste and discharges it overboard; Type II, which does the same but more effectively; and Type III, a holding tank that stores waste for disposal at pumpout stations or, in some cases, allows for direct discharge overboard when in permitted areas. It is essential to follow the regulations for the specific type of MSD and the designated No Discharge Zones (NDZs).

Frequently asked questions