Environmentally friendly water treatment solutions

With thanks to Aegina

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While not a new topic, environmental damage related to drinking water has become increasingly amplified over the last ten years. It’s estimated that superyachts consume as many as 40 million litres of bottled water per year, much of this packaged in plastic.

While discerning guests require confidence in both the taste and safety of drinking water and hard-working crew need to maintain their hydration, especially in warmer climates, the consumption of water itself cannot be reduced. With this in mind, we can look both at how we consume water and ensure that we do so safely.

When picking any method of water treatment, it’s important to weigh up all the factors and decide how you use your water, and what for. Going for the cheapest option in the first instance may not pay off in the long term as you can ‘buy cheap - buy twice!’. With plastic waste in our oceans becoming an ever-increasing problem, we all have a responsibility to reduce our reliance on it and find long-term, eco-friendly solutions.

Water will be brought on board one way or another, in bottles, into holding tanks from a standpipe or through the reverse osmosis de-salination process. Kevin Peart of AEGINA-PURE runs through some pros and cons of various methods of ensuring that what comes out of the faucet is up to scratch.

Bottled

Glass bottles:

Pros – Convenient, consistent and hygienic. Recyclable.

Cons – Expensive, heavy and risks of injury through breakage. Energy-intensive to recycle.

Plastic bottles:

Pros – Convenient, consistent, hygienic and safe. Lack of consumer clarity as to whether recycled/recyclable.

Cons - Potential for devastating land- or water-based pollution after use. Expensive.

Filling up fresh water tanks

On-board tanks make for a space efficient and convenient water storage solution and entirely cuts out the waste issue. The most commonly used methods are:

Standpipe:

Pros – Cheap, accessible.

Cons – Depending on location, the quality of water may be questionable.

Reverse osmosis/Watermaker:

Pros – Removes most contaminants, limitless supply for long passages. Convenient.

Cons – High waste (approx. six times the amount of clean water), requires a lot of power, space and maintenance. High initial installation costs.

The overriding drawback of relying on tanks is the unpleasant ‘tank-taste’ that anyone who grew up sailing small yachts will know all too well. The taste is certainly not superyacht standard and that’s not all – tanks can also prove to be a perfect breeding ground for bacteria such as Pseudomonas, Escherichia coli (E.coli), Coliforms and Legionella pneumophila which would pose a danger to crew and guests alike.

Potable water tanks can be treated with chemicals such as chlorine or copper but this can add to the unpleasant taste. Chemicals also add an additional level of risk implicit in handling chemicals and the potential of environmental harm.

Other options

Microfiltration by using filters with pores of less than 10 microns is one solution that physically removes bacteria, amoebae and algal blooms in the filter, and this certainly has the ability to remove harmful bodies from the water, but it’s worth noting that filters like these need sufficient water pressure and there is maintenance involved. Generally this sort of filtration reduced flow rates significantly.

Charcoal filters are well used in the outdoor market where portable water filters are essential to make stream or lake water safe for drinking. They may not filter to the extent of microfiltration and there is a compromise in terms of removal of harmful bodies but, in favour of charcoal filters, is that it proves effective in removing some of the unpleasant taste.

UVC LED purification is a relatively new technology and British firm PRP Optoelectronics, creators of AEGINA-PURE, has used technology that it more typically uses in fighter jets and targeting systems to offer a solution that delivers Class-A pure water on demand and can handle relatively high flow rates. This is a low-maintenance and easy-to-retrofit system that, as so much of the bad taste of tank water can come from bacteria, also leaves it tasting less stale.

Perhaps running UVC LED purification in tandem with charcoal filtration to deliver both safe and tasty water from on-board tanks is a viable option. If combined with on-demand chilling and carbonation devices such as Octo Marine’s M70 unit and the Yachting Pages Water Bottles, it could be the answer to provide a safe and ‘superyacht standard’ sip of water to guests and crew alike.

We hope to see continued developments in both purification of drinking water and also removal of poor tastes in the coming years to ensure that yachting is doing less harm to its playground with plastic.

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