Sulphurous smelling tap water

MoodySabre

MoodySabre

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I was sailing on a friends boat last week. It's a 4 year Oceanis 31 in immaculate condition. When he ran the tap the stench of sulphur (bad eggs - hydrogen sulphide?) was very strong and I was in the cockpit! This also happened again later in the day. I've had that pong from the loo inlet first flush which I understand but from the tap in the galley? Whatever is gong on to cause that?

(It was the other thread about sulpherous (sic) smells that made me think of this).
 
Presumably some horrible bacterial infestation of the freshwater system. Yuk.

If it were mine, I'd give the tank several massive doses of cleaning stuff each left for 24 hours or more, interspersed with clean water flushes, and probably replace all the hoses too. If at all possible, get the lid off the tank for a manual scrub first, there's probably a thick layer of slime on the inside. Then once clean, keep it that way with a normal dose of cleaning stuff each autumn and spring.

This is what I did with Ariam's water system when we bought her (it had a little bit of a "boaty" taste, but nothing like your mate's stench) and now the water from the galley tap tastes identical to my kitchen and I drink it by the pint with no worries at all.

Pete
 
MoodySabre said:
I was sailing on a friends boat last week. It's a 4 year Oceanis 31 in immaculate condition. When he ran the tap the stench of sulphur (bad eggs - hydrogen sulphide?) was very strong and I was in the cockpit! This also happened again later in the day. I've had that pong from the loo inlet first flush which I understand but from the tap in the galley? Whatever is gong on to cause that?

(It was the other thread about sulpherous (sic) smells that made me think of this).
Click to expand...

I am not a biologist but it seems that anaerobic conditions have allowed the bacteria that thrive under such conditions to become established. They attack the sulfates in the water leading to the formation of hydrogen sulfide.

A good tank clean with Milton, another chlorine or sodium dichloroisocyanurate based tank cleaner even household bleach is called for.

The normally mild mannered Sarabande would have explained in more detail but still seems to be banished to the other place for saying "boo" to one of YBW's geese.
 
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Def sounds like an anaerobic situation.
I have a different smell- when running the fresh water tap the water has a rock pool smell (for want of a better term) for about 30 seconds. After that it's all clear and no more smell till next time the water has sat for a week or two. I use Elsil water treatment - peroxide and silver based - as used in aircraft potable water tanks. The water tests at the correct peroxide level so nothing should be growing.
It must be some strange process in the pipe work but I have no idea what?
Next step, submit a sample to a water test lab?
Any thoughts gratefully received.
Andy
 
VicS said:
I am not a biologist but it seems that anaerobic conditions have allowed the bacteria that thrive under such conditions to become established. They attack the sulfates in the water leading to the formation of hydrogen sulfide.
Click to expand...

Quite right. The unfortunate Oceanis' water system has become oxygen-poor allowing anaerobic sulphate-reducing bacteria to produce H2S as a by-product of metabolizing organic matter. https://en.wikipedia.org/wiki/Sulfate-reducing_bacteria

This is the kind of thing you find going on in very unpleasant place such as (geologically) the sediment beneath the deep sea floor, in sour crude oil, and once in a large vat of screenwash which lay undisturbed until it's keeper decided to top up every car in a 60-motor corporate fleet with the stuff in order to get rid of it (made my summer). It is not the kind of thing you want going on in a yacht's freshwater system.

The tank has basically become stagnant and lack of use is the main culprit. It is also not terribly clean (organic matter is present) and the sulphate is probably coming from the freshwater but don't rule out a seawater leak.

Open everything up, dry and air it out, milton it as recommended above andrun the taps now and then- don't let it go stagnant again.
 
Fit and use a shower. That keeps the water flowing and fresh. My pressurised system stays fairly fresh, though I use a filter on the cold side, but tea made from the hot also tastes ok. My only problem is the foot-pumped outlet to the sink, which gets a bit whiffy, so I try to use it as often as possible to prevent the line getting stagnant.
 
I bung in a couple of Milton tablets when I fill the tanks, to get the level of Cl to about 1ppm; a small quantity of bleach would do the same. It would be OK to drink at this level, although I normally drink bottled water as it is kept in the fridge, and only costs €0.80 for 8 litres.

I occasionally give a tank a blast of 10ppm Cl when leaving (about twice the level in a public swimming pool), by the time we go back to the boat the chlorine smell has gone.
 
The calorifier on our boat goes sulphurous if we do not use chlorine tablets (we use aquatabs) which makes the water unpleasant to drink, the previous owner fitted a Natur Pur filter made by General Ecology (about £300) and this produces high quality drinking water on tap, no chlorine or boat tank tastes.
 
There is lots of good advice here so there is no point in my repeating it. I would add that my advice is to fit a General Ecology water filter and faucet, they will filter out everything including e-coli. We use the faucet on our boat for anything we drink or cook with. Yes they are expensive but I think it is really worth it because you can drink all the water in the tank no need for battled water and you are not too worried about the quality of water in the tank either.

http://www.purewateronline.co.uk

PS I have no connection,just a satisfied customer.
 
Seven Spades said:
There is lots of good advice here so there is no point in my repeating it. I would add that my advice is to fit a General Ecology water filter and faucet, they will filter out everything including e-coli. We use the faucet on our boat for anything we drink or cook with. Yes they are expensive but I think it is really worth it because you can drink all the water in the tank no need for battled water and you are not too worried about the quality of water in the tank either.

http://www.purewateronline.co.uk

PS I have no connection,just a satisfied customer.
Click to expand...


+1 for General Ecology filter
 
nigelmercier said:
When you cost the price of filters compared with cheap bottled water, there is little difference in the ongoing costs, so the initial outlay of the filter is never recovered. In addition, bottled water can be kept in the fridge.
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I just re-fill the old water bottles from the galley tap and stick them in the fridge. Don't tell the crew though ..... they all think that they're drinking shop-bought bottled water! :o

I'm from Yorkshire!

Richard
 
nigelmercier said:
When you cost the price of filters compared with cheap bottled water, there is little difference in the ongoing costs, so the initial outlay of the filter is never recovered. In addition, bottled water can be kept in the fridge.
Click to expand...
Except you never have to cart bottles of water out to the boat...

It's worth reading the PBO water filter test from about 1-2 years ago, as the view was that Poole tap water made the best tea after being passed through a GE filter... I still treat the tanks with Puraclear every year, but all visitors opinion aboard is that tea aboard Gladys tastes exceptionally good
 
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I think this is reasonably common with flexible pipes especially. Often / usually the cause is biology (bacteria / fungi) in the pipes, not the tanks. Flush the pipes with bleach (the best source is pure bleach in powder form used for hot tubs) solution and leave for a few hours or so. The water will stay pure, clean and fresh spelling for a few months or more, at the first sign of any smell repeat etc. If the system is being used daily the problem doesnt occur, its the stagnant water that is the cause. Treating the tanks is fine but often unnecessary and risks the corrosive effect of introducing bleach (which may or may not be an issue depending on whether the tanks are plastic, fibreglass or metal, moreover its much simpler to flush the solution out of the pipes. I have a T valve in the pipe where in comes out of each tank which simplifies switching to a tube into a pot with the bleach solution, running each tap, shower etc to suck the solution into the system, leave and then flush through each pipe a few hours later.
 
AFAIK the sulphate reducing bacteria use the sulphate as an oxygen source, and still need a carbon source - which could be from plastic leached from tanks and/or pipes (assuming the organic carbon level in the water itself to be low). We have a stainless tank and 'hard' plastic plumbing (Guest Speedfit) and find that simply using Aquatabs on every filling keeps it all sweet.
 
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