Drinking water quality

[Big COL]

I have just read an article on water quality, and it prompted me to look at the function that my water filter on the boat actually performs, it being one of the commonest types used on narrow boats. It states that this filter is not a water purifier see link http://www.xor.org.uk/silkroute/equipment/purewater.htm what standard of water quality do you think is acceptable.

I personally think that we live in a too sterile world regarding what we eat and drink, to the detriment of our own immune systems. Having said that I am fully aware that the majority of the real nasties are waterborne so what is an acceptable filtration system for narrow boats?

[John Orentas]

I have always been a bit sceptical about filters. It goes without saying that even the best filters in the world can only catch molecules which are larger than those of water, most chemical contaminants will go straight through.

 

In industrial applications it is common to use UV light to kill the living nasties, I am always surprised that domestic models are not available, you could easily conceive of a system using a small pump and UV steriliser running continuously circulating the water from the tank and back again.

[Big COL]

I have always been a bit sceptical about filters.  It goes without saying that even the best filters in the world can only catch molecules which are larger than those of water, most chemical contaminants will go straight through.

 

In industrial applications it is common to use UV light to kill the living nasties, I am always surprised that domestic models are not available, you could easily conceive of a system using a small pump and UV steriliser running continuously circulating the water from the tank and back again.

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John

 

Sounds like a very good idea, perhaps you have identified a niche in the market. I know you can get them for fish ponds, perhaps one of these would be adaptable.

Edited February 12, 2005 by Big COL

[Paul Evans]

You can buy water sterilising tablets that you add when filling the tank to kill off the nasties and one of those Britta Filters if you really want to drink water straight from the tap. This avoids the need to adjust your plumbing.

 

I don't worry too much about any of this unless I have left water sitting in the tank for any length of time. The water supplied from water points meets UK drinking water standards and as long as you turn it over fast enough you should have no problems. If I have left the water sitting for a long period, I run it off and refill the tank. So far, no gyppy tummy or other ill effects.

[Big COL]

You can buy water sterilising tablets that you add when filling the tank to kill off the nasties and one of those Britta Filters if you really want to drink water straight from the tap. This avoids the need to adjust your plumbing.

 

Have you ever tasted any water after treating it with sterilising tablets its awful.

 

The water supplied from water points meets UK drinking water standards

 

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This is the very point that started me looking at what my filter actually did.

[Speedwell]

I never really doubted that the water met drinking water standards when it went into the tank but it is probably not so good after it's been there a few months (years ?). We have a water purifier for drinking water, which claims to produce bottle quality water from tank water - it certainly seem very good. The filter is a doulton candle filter, which is a fine ceramic filter containing silver, which kills germs. The literature with the new filters says they are used to produce drinking water from tropical streams in third world aid missions. If they can do that, they should find boat tanks easy !

[ChrisPy]

I suggest we approach it from a more realistic standpoint:

 

1. the water that goes into the tank should be of potable quality, and that is often checked by the water company measuring the residual chlorine level at the outlet (in theory). Any residual chlorine means all the bugs are dead.

2. the water tank and pipes should be sterilised when you commission the system, just like in your home.

3. the system should be designed and operated to avoid any risk of contamination, just like in your home. We don't yet have bylaws (BSS) to prevent contamination in boats, but I'm sure everyone is familiar with the laws on standpipes, bath taps, and the like in your home.

4. you will pick up grit and other solids from the tank occasionally, so you filter them out. Coarse filter at the pump, fine filter at the drinking tap.

 

So in theory the solids filter is all you need, and even without it the water should be safe, even if it sometimes tastes a little strange.

[DHutch]

You can get them for fish ponds, perhaps one of these would be adaptable.

 

Yeah, im sure you could use one of them, if you got one of the UV only units, rather than the UV/Filter combo units. The only problem i cold see is that the UV light is going to draw a certain current when ever it on (the smallest uv units use 5w bulbs, so draw about 6w, and there all 240v)

 

- I know a lot of water coolers in offices (like my dads, and our 6th form common room) Use UV filters, would be interesting to see weather the bulbs are on 24/7 or if there cleverly switched on with the refigeation unit?

 

 

daniel

[timboharticus]

 

Quote " never really doubted that the water met drinking water standards when it went into the tank but it is probably not so good after it's been there a few months (years ?). We have a water purifier for drinking water, which claims to produce bottle quality water from tank water "

 

My understanding is that bottled water is not subject to the same stringent standards as tap water. So, save your money!

[John Orentas]

Why should water that has been in your tank for a few months be any different from "Fresh water". All the water we have access to is millions of years old, it may be a bit de-oxygenated that is easily remedied.

 

I am not aware that there is or ever has been any problems with the water stored on boats. Everyone is looking for trouble where none exists, if water tastes ok it is safe to drink.

[Rose]

Why should water that has been in your tank for a few months be any different from "Fresh water".  All the water we have access to is millions of years old, it may be a bit de-oxygenated that is easily remedied. 

 

I am not aware that there is or ever has been any problems with the water stored on boats. Everyone is looking for trouble where none exists, if water tastes ok it is safe to drink.

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Has anyone ever used one of those strange filters I once saw demonstrated at the NEC boat show, where you can actually filter CANAL water and it is fit to drink. well it looked very impressive, but I wasn't brave enough to try any !!

[James York]

That filter was probably a RO filter. The water that came out was probably better than normal tap water. All our tap water is RO filtered and it makes tap water taste tangy and the water is much softer.

[Alan Saunders]

Assuming the water at the water point is good and no light enters the storage tank the chlorine level should diminish very slowly if at all. If the tank is completely sealed and the breather in a suitable position it is unlikely to become contaminated. The filling hose is a weak link in the process. Ideally the hose should be endorsed as suitable for potable water - some people claim that they can taste the taint introduced by their hose. Also the damp interior of the stored hose is an excellent breeding ground for everything from bacteria to spiders, even snails.

 

I am happy to rely on John's assertion that 'if it tastes ok it is safe' but I would not trust that for children or old people who are likely to suffer greater harm from dehydration caused by bugs in the water.

 

The whole question of water filtration, also recently discussed on uk.rec.waterways, seems to have a mythical quality; boats have been seen with filtration systems but no-one knows where to buy them! I would be very interested to hear of an efficient, economical solution. Topping up every day when cruising is not a problem; mooring for a week or more may require considerable effort to fill the water tank.

 

Alan

[James York]

Here is a very good RO unit. The stats speak for themselves!

 

RO unit

[dor]

Why should water that has been in your tank for a few months be any different from "Fresh water".  All the water we have access to is millions of years old, it may be a bit de-oxygenated that is easily remedied. 

 

 

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So why does bottled water have a "best before" date giving a shelf life of a matter of months?

[James York]

I imagine that is because the water is not sterile and so after a few months bacteria levels start to rise to significant levels.

 

I should add that water in the natural environment is subject to "good bacteria" which helps break down "bad bacteria" this process is not present in your water tank as the conditions are not right.

Edited February 15, 2005 by James York

[ChrisPy]

So why does bottled water have a "best before" date giving a shelf life of a matter of months?

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nearly everything that is consumable now has a best before date in the EU. Probably for commercial reasons as much as anything.

 

I recall working in Oman in 1980s when they introduced a sell by date for wine. I think it was 18months after the production date. There was a huge bargain sale, and shortly after all the remaining old wine was poured down the drains!!

[James York]

Many people keep wine years to age it. However it has to be of a high quality to do this otherwise the grapes go off.

 

but i have gone

[ChrisPy]

Many people keep wine years to age it.

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no !! really ??

[Paul Evans]

Not in my house they don't. I keep explaining to the OCM that if we buy good quality wines and store them properly they will be even better in a few years' time. All she has to do is ask if I fancy a glass or two (three's better) and that's my cellar gone. Oh well, I'm off to the pub for a glass or three of Rioja Reserva.

[Big COL]

Why should water that has been in your tank for a few months be any different from "Fresh water".  All the water we have access to is millions of years old, it may be a bit de-oxygenated that is easily remedied. 

 

I am not aware that there is or ever has been any problems with the water stored on boats. Everyone is looking for trouble where none exists, if water tastes ok it is safe to drink.

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Things tend to crawl into the tanks through the overflow pipe and then die. This must change the bacteria balance that previously existed.

[James York]

i should add that wine has the be kept in controlled conditions. If the tempreature was to rise or fall byt only a few degrees the wine would go off.

[ChrisPy]

i should add that wine has the be kept in controlled conditions. If the tempreature was to rise or fall byt only a few degrees the wine would go off.

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now you're just trying to wind me up.

[Alan Saunders]

i should add that wine has the be kept in controlled conditions. If the temperature was to rise or fall by only a few degrees the wine would go off.

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It depends what stage of maturity the wine has reached. Wine can be matured rapidly by alternating the temperature. For that purpose port wine used to be kept in the holds of ships traversing the tropics and the temperate regions for a couple of years. Méthode Champenoise involves freezing the neck of the bottle! You have to be a connoisseur to believe the temperature is that critical.

 

High water temperatures will accelerate the loss of chlorine and the growth of bacteria in a tank. The preservative in the wine, beer etc. is alcohol and I seem to remember that 'hopping' helps too; not practical for use in the average narrow-boat tank.

 

Teacher:

(puts a worm in a glass of whisky - worm dies)

"What does this teach you"!

Pupil: "If you've got worms, drink whisky, sir"!

 

Alan

Edited February 17, 2005 by Alan Saunders

[Amicus]

Chat-arry here uses UV and carbon.........

 

http://www.espring.com/English/Products/doc8061.aspx