Grey Water: The Silent Killer
Grey Water: The Silent Killer - PYA (*)
The facts surrounding GREY WATER, otherwise known as 'the silent killer', are anything but grey. They are stark, shocking and uncompromising.
“All this is often pumped directly into the ports, anchorages and seas, some is mixed untreated in the on-board sewage treatment plant. The damage to the environment is ‘immeasurable’.” Dr John Hoskins, independent chemist and toxicologist.
The facts surrounding GREY WATER, otherwise known as 'the silent killer', are anythingbut grey. They are stark, shocking and uncompromising. They are black and white.
This major polluter of the marine environment, especially so in ports and coastal areas, comes from the untreated water, often laden with chemicals toxic to the marine environment, from a yacht's/vessel's galley sinks, showers, washing machines and dish washers. Unlike black water, which is the ship's sewerage, it contains many compounds that will not eventually break down or bio-degrade. Its effects can devastate aquatic life, but it's called a silent killer because you swim in it, too!
Grey tank chemicals contain an array of pollutants from the highly chemical -- bleach, strong acids from some cleaning products (giving it a high pH) or strong alkalis from others (low pH), including many detergents, phosphates, whiteners, and foaming agents -- to oil and grease, suspended solids and organic particles. The biggest producers of grey water are washing machines because they create the largest volume of waste water . Laundry detergents, the biggest polluters, contain phosphates that encourage rapid algal growth. Overrun by algae, eco-systems are eventually depleted of oxygen, causing fish and other aquatic life to suffocate. This is called an EUTROPHIC effect. In addition, degreasers found in washing up liquids and soaps strip the natural oils from fish gills making it difficult for them to breathe.
The best way to counteract this massive, cumulative damage is to use eco-friendly products. “There are no chemical-free products,” says Sheila Goddard of Environmental Yacht Services,. “But which chemicals, how to use them and, most importantly, how to dispose of them – those are our concerns.”
One of the myths of all crews, including some engineers, is that the black water treatment system treats grey water. This is FALSE. When organic black waters ( containing feces) are mixed with their more toxic, chemical counterpart, grey water, the cocktail is even more dangerous. They should be kept apart. Black water treatment systems do NOT treat grey water. Each must remain in their respective holding tanks,and then be pumped out, preferably at a pumping facility and not into the ocean or sea. Another industry fallacy is that there is a mechanical system that purifies the grey water before it goes into the ocean. One does exist manufactured by ‘Rochem’ but it is VERY big and expensive .
It is important to remember that ships, even those with the most up-todate bio-reactors, cannot compete with land-based waste-water treatment plants or sewage works that remove unwanted chemicals effectively. Legislation for mandatory pump out regulation is imperative if we want to avoid an eventual environmental disaster. The amount of waste water being discharged into ports is unacceptable and has been for many years. To put it into perspective, an average swimming pool 6 x 4 x 2,5 m contains approx. 60,000 liters of water; an average 50 m yacht with 15 crew plus 12 guests uses at least 16,000 liters per day. Regulations will take a long time to come as the damage being caused has not been highly recognized by MARPOL, who oversees all worldwide shipping, but who do not regulate grey water except when it is mixed with the black.
MCA, Maritime Coast Guard, have no regulations either. In fact, the only places where regulations are in effect are the Australian Murray River Basin, along the ports of the American east coast, and in certain areas in Alaska and Canada. As of 2009, one is obliged to respect the VGP (vessel general permit) when entering the US ports where environmental regulations are written and enforced. The Mediterranean is particularly vulnerable and has a very slow renewal rate at a minimum of 25 years.
Ports and coastal regions, in particular, are highly vulnerable as they have slower circulation than the open sea. Septic grey water can be as foul-smelling as black waste. Because the tanks are closed, oxygen is depleted creating an anaerobic environment This is also due to the type of products used on board - especially in the laundry. Washing clothes and bedding, is responsible for most of the waste water in the grey tanks. The key to successful grey water treatment lies in the amount of oxygen in the tank and the colonisation of the tanks by special microbes that can deal with at least some of the chemicals present.
To reduce their environmental impact, yachts need treatment systems for grey-water which do the same job, so far as possible, as land-based waste-water treatment plants. Unfortunately, this technology for yachts is not required, easily accessible or promoted in the industry. The problems can be solved, however, with the addition of a Grey Water Additive (GWA), a blend of selected microbes that introduce microbes into the tank. When distributed through the pipe work, sinks, showers and drains, these microbes reproduce naturally and rapidly, cleaning and breaking down the tank's sludge. Specially designed for easy use on board yachts, GWA is dispensed via an easy-to-handle customized system - no mess, no hassle, no bother. Used as directed, it removes much of the dissolved organic waste and emulsified fatty substances in grey waste water, preventing putrefaction and odour.
The more neutral, grey tank liquid becomes the less it smells and the safer it becomes for the environment. .
WHAT IS IN YOUR SHIP'S WASTE WATER?
- Automatic washing machines: the waste water from these contains bleach, a high pH, oil and grease, phosphate, whiteners, soaps, foaming agents, suspended solids….
- Automatic dish washers: the waste water from these contain bacteria, food particles, Phosphates, caustics high pH, oil and grease, organic matter, detergents, suspended solids….
- Baths and shower water: contains bacteria, hair, oil and grease, soaps, suspended solids…
- Galley and pantry sinks: the waste water contains bacteria, food particles, odour, oil and grease, organic matter, detergents, chlorine bleaches and suspended solids.
(*) PYA is a not for profit association run for crew by crew. Founded in 1991 in response to the creation of the first Large Yacht Code (LYC). We have a long history of working with policy makers tasked with writing rules and regulations that affect yachts and yachting. Throughout the evolution of manning and certification regulations affecting crew on large yachts, we have been there putting across the point of view of those who actually live and work onboard yachts. Our Head Quarters is in Antibes, France and we have 15 Regional offices world wide. Our staff offer up to date, informed advice on training and certification issues along with practical information on how to proceed with disputes with employers.
Key words: grey water, environmental, ship, wastewater, ro rochem, wastewater treatment
