How are black water processed on leisure boat

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What is blackwater and how does it affect aquatic environments?
What are your options for dealing with blackwater?
Did you know?
Definitions
Requirements
What is black water on a boat?
Does greywater become blackwater?
Where does the black water come from?
Is GREY water the same as sewage?

What is blackwater and how does it affect aquatic environments?

Sewage discharge (also known as blackwater) contains pollutants including nutrients, metals, toxins and pathogens. Blackwater discharged from your boat can impair water quality, negatively affect aquatic ecosystems and increase risks to human health.

The law

Under federal law, it is illegal to dump raw, untreated sewage into navigable U.S. waters, including coastal waters within 3 miles of shore and inland waters (lakes, reservoirs, rivers, etc.). A No Discharge Zone (NDZ) takes this law a step further and prohibits the discharge of both treated and untreated sewage into a designated body of water.

A NDZ is created if a state determines that a body of water either:

Requires greater environmental protection and there are adequate pumpout facilities available.
Has particular environmental importance (e.g. sensitive areas such as shellfish beds or coral reefs).
Or has drinking water intake zones.

It's important to know the locations of any No Discharge Zones and pumpout stations in the areas where you are boating. The U.S. Environmental Protection Agency (EPA) provides a list of NDZs and pumpout facilities by state.

All boats in U.S. waters with permanently installed toilets are required by federal law to have a Marine Sanitation Device (MSD) onboard that either stores sewage until it can be transferred ashore, or treats sewage to reduce the coliform count to such low levels that discharged blackwater poses no public health hazard.

What are your options for dealing with blackwater?

There are several ways to handle blackwater onboard your boat, including the following:

1. Direct Discharge: If you are boating in locations that do not have waste pumpout facilities, try to discharge your waste overboard while underway in deep water away from beaches and anchorage sites. Pumping out your waste near shore is harmful to swimmers, snorkelers, divers, other recreational users, and those who eat the local fish and shellfish.

2. Portable or Composting Toilet: They don’t require installed water, power or holding tank, and are great for weekend trips. Check out Nature’s Head and Air Head Dry Toilet for composting options.

3. MSD Type III: For regions with adequate pumpout facilities, a holding tank connected between your head’s discharge and a through-deck pumpout fitting is simple, inexpensive to install and meets the requirements of the law.

4. MSD Type III with Optional Overboard Discharge: In addition to the deck pumpout fitting, a Y-valve can be placed after the holding tank, so sewage can be directly dumped overboard beyond the three-mile limit, if based in the US. Y-valve must be secured in the off position to prevent accidental discharge of untreated sewage.

5. MSD Type I: All of the waste is treated by maceration or chlorination before entering the holding tank or being directly dumped overboard. Offshore recreational boats generally use this type of MSD.

*There is a MSD Type II, which treats sewage through aerobic digestion. However, it is generally found on large commercial vessels.

Did you know?

Discharge from a single boat over one weekend contributes the same amount of bacterial pollution as the treated sewage from 10,000 people (California State Water Resources Control Board)!

The Code of practice for vessel and facility management (marine and inland waters) contains the mandatory requirements for vessel operators managing black and grey wastewater whilst travelling in state waters.

Definitions

blackwater is any waste from toilets or urinals
greywater is wastewater that has been used for washing, laundering, bathing or showering
wastewater includes both blackwater and greywater.

The EPA is satisfied that reasonable and practical opportunities exist for vessel operators to provide on-board wastewater management systems suitable for the vessel and its operational requirements in either marine or inland waters. This will reduce the environmental and public health risks associated with discharging vessel wastewaters into South Australia’s aquatic environments.

There is evidence that our aquatic environments are declining in water quality and while this is attributed to pollutants from a number of sources, namely effluent discharges from sewage treatment works, industrial wastewater, farming practices and urban stormwater runoff, there are increasing calls for all contributors to accept responsibility and reduce their environmental impacts for reasons of future sustainability.

One small recreational vessel can cause significant harm through the release of its wastewater, especially in sensitive aquatic areas. Recent closures of marine shellfish collection and farming areas due to the presence of faecal contamination have impacted significantly on the fishing industry itself and the wider community. Increasing numbers of houseboats with ensuites, spas, dishwashers and washing machines moored alongside one another on the River Murray can pose health risks, both to those on board and other recreational river users through the discharge of greywater.

Requirements

The requirements are set out in the Code of practice for vessel and facility management (marine and inland waters). This code is linked to the Environment Protection (Water Quality) Policy 2015. It contains compulsory requirements that operators must follow when managing blackwater (toilet waste) and greywater (wastewater that has been used in the kitchen, showers, sinks and laundry) on your vessel.

The code also lists recommended practices which inland waters vessel operators should adopt to better manage greywater onboard.

What is black water on a boat?

There are three terms which are commonly used to distinguish the different types of waste water created on boats: black water, grey water and bilge water. Black water is toilet waste i.e. waste which will often contain harmful bacteria and viruses. Grey water is waste water from sinks, showers and washing machines.

Does greywater become blackwater?

Motorhomes have tanks which collect grey water for later disposal. That's handy, but storing grey water for longer than 12 to 24 hours will turn grey water into black water.

Where does the black water come from?

Blackwater: is the wastewater from bathrooms and toilets that contains faecal matter and urine. Water from kitchens and dishwashers are also considered blackwater due to the contamination by pathogens and grease (Department of Industry, Science, Energy and Resources 2013, Your Home, Australian Government, Canberra).

Is GREY water the same as sewage?

Greywater can be defined as any domestic wastewater produced, excluding sewage. The main difference between greywater and sewage (or blackwater) is the organic loading. Sewage has a much larger organic loading compared to greywater.