Danger of Stagnant Water in Your home

DavidFx

tacpot12 wrote: »

The process I would use is:

Wear a half-face respirator rated to stop bacterial, e.g. eg Eclipse P3 (available from ScrewFix and Toolstation), close-fitting Safety Googles, and Waterproof gloves

Drain the water out of the tanks into a large saucepan or billycan with a lid. This needs to be done in a way that minimises the creation of droplets/sprays/mists. A small hand operated pump could work to empty the header tanks from the top, or you could try to get a hose onto one of the pipes beneath the valves that have been turned off. Same with the hot water cylinder to drain it. Have some fresh water in the bottom of the saucepan and have the outlet from the pump or any drain hose weighted so that the foul water is discharged under the level of the fresh water. Have the lid on when filling the saucepan, and pull the hose out and drop it into a bucket of fresh water while you bring the saucepan out of the loft. Ideally the bucket will have a close fitting lid.

Put the lid on before bringing the saucepan out of the loft.

Boil the water on the hob. You need to wait for 1 minute after the largest bubbles are seen (called a rolling boil). The water will then not contain harmful levels of legionalla and can be disposed of down the toilet or sink, but not a rainwater sewer. Refill the saucepan with fresh water and return to the loft for as many times as it takes to empty the tanks.

Use a microfibre cloth to mop out the header tanks until they are dry. Gently wring it out into the bucket of water, being careful not to create unnecessary droplets. if the bucket has a lid, pop it and take the water to the hob. Be careful to pour into the (same) saucepan slowly. Boil the water and the microfibre cloth in the saucepan as above (rolling boil for 1 min).

Wash the saucepan, ideally in a dishwasher as these also use water hot enough to kill legionella bateria.

Or ... you could pour in a bottle of bleach.
Wait an hour.
Syphon out with a hosepipe.

Fire_Fox

Only a couple of generations ago this discussion would be more like "duck pond or home brew?" :drool:

Rambler1

Thanks to all respondents for their input. Just to clarify a few points:
1. We asked the council if there was a health risk and they suggested Legionnaire's disease as a potential risk. This was supported by the water company, hence their reluctance to have the water in their drains.
2. We have no way of knowing when the boiler conversion took place and therefore how long the water has been there.
3. The issues with regard to leaving it is that in severe cold the tank could freeze and empty its contents into the bedrooms, it holds about 50 gallons.
4. Surveyor may have seen the tanks there but would probably assume that they were all empty as that would be the correct way to leave them.

The point of the post was to warn everyone of the potential issue due to a job being only half done.

AndyMc.....

Is the tank insulated and is the loft insulation under it?

It hasn't frozen and burst yet.

tacpot12

Norman_Castle wrote: »

As I never use the hot tap on the kitchen sink could this cause similar problems?

Yes, legionella bacteria will thrive in situations where the water is stagnant but warmed above 20 degrees C. This can happen when a branch of pipework remains unused for long periods, like your kitchen tap.

As I stated in my post, legionelle risk is somewhat overstated, BUT it would be as well to run scalding hot water through the kitchen tap for a few minutes every year to minimise the risk. Another cause of legionella is people that have a hot water cylinder having the thermostat on the cylinder turned down too low so that the water in the cylinder is normally at less than 55 degrees C. This is commonly down to avoid the scalding risk and to save energy. If you have turned the thermostat down, turn it up to 70 degrees C a couple of times a year - ideally when you are the only person in the house or no one is in (say if you are out visiting friends) - just leave yourself a note to turn it back down again.

Best practice in plumbing is now to remove ALL redundant pipework for the reason highlighted by the OP.

getmore4less

In most houses the water in the cylinder will get replaced every day or so with fresh chlorinated water except when away.
(will depend on the number of baths/showers)

RedbullRJ

Another vote for gently stirring in a bottle of bleach, leave for over an hour (24 hours to be doubly sure) and syphon with hose down toilet or bath. (Start the syphon going with a clean bucket of water so you don't risk getting a mouthful of bleached water and tank debris)

getmore4less

You never(nearly) need to suck start any siphon
You prime the siphon tube.

I would go longer and have the exit point outside the house but not essential.

Ganga

getmore4less wrote: »

You never(nearly) need to suck start any siphon
You prime the siphon tube.

I would go longer and have the exit point outside the house but not essential.

Thats the way i would do it,get someone to hold the hose in the loft above the tank and fill it with water from a tap on the ground floor,when full put their finger over the end and put the hose in the tank right to the bottom and then let the water run backwards from the tank back down the pipe into the garden where it will be filtered before soaking away,job done,remove tanks.:T

Mr.Generous

On my IOSH course the guy taking it said legionella bacteria is just about everywhere, any puddle there for more than a couple of days. As someone said the danger comes from inhaling fine vapour like from a shower.

Sometimes old tanks in the loft are metal and are bigger than the loft hatch. I've found them in renovation projects empty and disconnected but unless you sawed them up they are staying there.