Water storage tanks - above ground or below?

[UKJASE]

hey guys, we have started to build our house and the builder has offered us either to either put our two x 2000 litre water tanks in the ground, or above ground

the land plot is quite big, so space is not an issue

the builder thinks we should put them underground, as it looks better

but the wife thinks we should have them above ground in case they need maintenance

i tend to agree with the builder......

what do you guys think? would two plastic tanks sank into the ground likely need maintenance in the next 10 years or so?

are there any other issues we should consider? he says he will build the access lids slightly raised so flood water will not drip into the tanks..... what else needs consideration?

thanks in advance for any advice / opinions

[MJCM]

In my wife's house we have the tanks below ground, but the reason being that the water pressure in the area is very low so now the water just flows in.

If you have good water pressure I would recommend having your tanks above ground, reason being, it's a ... of a job to dig out the water tank in case of a leak

Edited April 8, 2014 by MJCM

[eyecatcher]

Actually your wife has an opinion and a reason for it......a good reason.

It doesn’t really matter whether its under ground or above ground. If your tank is sited in an area where you don’t want to see it or if your land space is limited, it might be better to put it below ground.

Tanks for above or below ground are generally the same material, such as bonded nylon but below ground you need to construct a chamber to protect it as they cannot withstand the pressure of the ground around them.

In particular if like most areas the ground is clay the pressures created by heave in the wet season will damage a tank.

So you need to consider the cost of excavating a pit and building a concrete “box”

Siting your tank above ground, this isn’t an issue.

With an above ground tank there is another advantage; it also means you can have a tap fitted to the tank near the base to draw off water without the need for pumping. Maintenance and access is also easier.

And if you don’t want to see it then you can always just add some trellis screens around it.

Whilst underground would at first look like a “no brainer”, your builder obviously prefers the extra work involved, than to tell you above ground is the easiest solution. The cost to you is definitely higher but if you have a rubber duck already on site that’s irrelevant..Personally i would also be fearful of building a custom made box for a tank that may need to be replaced by another (it can happen)

When I embark upon my project my water storage will be outside despite my limited space; possibly on a tower, as many are.

[Crossy]

Assuming you have space, above ground every time for all the reasons quoted above plus no danger of anything falling in if the lid is not properly secured (dogs, cats, kids).

The only negative is that the water tends to heat up so 'cold' isn't that cold, our tanks are shaded by banana trees so we cannot see them and the water stays (slightly) cooler.

[seedy]

Above ground. Build a shed around them, matching the house. Easy to look at, keeps water cooler.

[MAJIC]

Above ground. Build a shed around them, matching the house. Easy to look at, keeps water cooler.

I would favour above ground,and use the traditional clay storage tanks. filled up with rain water. Strangely these giant Urns,can have the Sun beating down on them all day,and give out the coldest shower you will ever have in Thailand,If you can take it without taking your breath away,then you are truly acclimatised Thai style!

[UKJASE]

thanks for all replies guys.... i think i did not explain myself correctly though

the builder has quoted us a set price for the house, and this price will not alter whether we have the tank below, or above ground

so, with no extra cost to ourselves, would you still think the above ground option is preferable?

the land is a countryside setting, and i felt that having two water tanks on display may distract a little from the idyllic outdoor setting

[Somtamme]

thanks in advance for any advice / opinions

There are two issues;

1. Quality: Preferable solution is below ground to help keep the water <20 degrees C. For both above and below ground tanks there should be provision for maintenance (isolating and flush valve) as it's good practice to clean/chlorinate the tank occasionally (to keep free from slimes and colonising opportunistic pathogens like Legionellla). if below ground the frequency for doing this should be less.

2. Sufficiency: Minimum acceptable pressure at point of supply (i.e. from the base of your tank) should be 10m static head or 1bar (14.5psi). Otherwise you'll need a pump on the outlet for hot/cold e.g http://www.salamanderpumps.co.uk/pumps

[eyecatcher]

Its a given in thailand that one or two pumps are the norm to raise water pressure.

Unless the tank is on a tower you are not going to get 10m head and a tower is quite obtrusive to say the least.

Salamander pumps are very common in the uk but only as a pump for showers.....power showers because all water storage tanks are in the roof with a max of 3m head or simply use direct mains water.

For the op the advantages of an above ground tank with pump outweigh those of an underground tank.

[Canada]

Mine are above ground. Many reasons I guess. I lived in a hut on this property while I built on it. First job was wash house. It made perfect sense to raise the tanks and use gravity to flow water to our toilet and shower in the wash house directly underneath the tanks. That's not your situation. However, with all the mucking around with waterworks, pumps etc., I would not put mine underground without having a large room to house them along with my pumps and filters. I pull out of a well, to the tanks, then pump to the house.

Now, our water house is the outdoor washroom for workers, and also houses our pressure washer for cars and the tractor and stuff like that. I also send water to the dog kennel from it and it serves as our dishwashing station. ( We only have small sink indoors, not a big house.)

Personally, I could not shower with water that was kept underground. It would be too cold for me. Our tanks are shaded by trees, but the water is great in the heat of the day. Makes for a perfect shower. Not hot nor cold.

[Somtamme]

Mine are above ground.....outdoor washroom for workers..... pressure washer for cars and the tractor and stuff like that......Personally, I could not shower with water that was kept underground. It would be too cold for me. Our tanks are shaded by trees, but the water is great in the heat of the day.

That's great but would you know what the signs of Legionella pneumophila?

[Langsuan Man]

This is Thailand, If it can possibly go wrong it will.

Think of the fun you will have trying to find a leak with an underground water tank !

[GinBoy2]

Personally I wouldn't put them underground, as others have mentioned any problems will be a nightmare to fix. The newer tanks actually don't look too bad. Mine are a kinda burgundy color, and with various plants around them they blend reasonably well.

Edited April 10, 2014 by GinBoy2

[UKJASE]

the builder guy who suggested we put them underground, who has worked here for 7 years and built 40 plus houses, says he has never heard of any problems occurring with the tank itself, and the requirement for it to be dug up

are there many likely scenarios where the tank would need bringing back out of the ground? i suppose when the rains come, the water table will rise a lot and the bottom end of the tank may be submerged in water for a period of time, which in turn could cause problems

do you know, are there tanks here that are designed especially for submerging into the ground?

also, is there no way that the builder could put a few of those concrete rings into the ground, and then put the tank within the rings, so if a problem did occur, the tank could be emptied and easily lifted out?

[seedy]

are there many likely scenarios where the tank would need bringing back out of the ground?

Do not know your soil conditions, or the terrain where you are building. But during the rainy season, the water-saturated ground exerts quite a 'Squeeze' effect. When the tank full, no problem. But when near empty, may be a problem.

The main one - or course - is if they spring a leak. Another poster started a thread a while back - the welds on his SS water tank started to sprout pinhole leaks. One off - ???

Will you put your pump underground with the tanks ?? Water pumps will push water much more efficient that pull it i.e. if pump is at the bottom level of tank it will not work as hard as if it is above the tank and must use suction lift to raise the water to ground level, and then push it thru pipes to the house.

Edited April 10, 2014 by seedy

[cheeryble]

Assuming you have space, above ground every time for all the reasons quoted above plus no danger of anything falling in if the lid is not properly secured (dogs, cats, kids).

…..now there's a thought.

Hmmm…..

[cheeryble]

Above ground. Build a shed around them, matching the house. Easy to look at, keeps water cooler.

I would favour above ground,and use the traditional clay storage tanks. filled up with rain water. Strangely these giant Urns,can have the Sun beating down on them all day,and give out the coldest shower you will ever have in Thailand,If you can take it without taking your breath away,then you are truly acclimatised Thai style!

Could you tell us more Majic

I favour the idea of cool and they may look well (well, get it?)

Price?

Porous or glazed?

Sizes?

Easy to cut holes in (if not so big they may need attaching in a series)?

etc.

[Crossy]

Assuming you have space, above ground every time for all the reasons quoted above plus no danger of anything falling in if the lid is not properly secured (dogs, cats, kids).

…..now there's a thought.

Hmmm…..

There's one dog I would willingly use as a test case.

Also if you have any danger of flooding an underground tank will be a liability and really nasty to clean out.

[lopburi3]

As you seem to have your mindset on what everyone advises against will add one more item - the new high quality pumps to increase water pressure are not designed to pump up from a well - only rated to lift one meter. You can use shallow well pump but why not get good water pressure and consistency from a Grundfos pump designed for the job?

When the power goes off it would be nice to have above ground tap to fill the bucket.

Septic tanks are indeed designed for in ground and will all immediately be filled with water to prevent damage - you do not want float in ground here and most places do flood at some time during the year. If that were also a time when water becomes low it could be a real issue.

Tanks can actually be very attractive (sandstone type and even SS is not exactly ugly). Do not know of anyone complaining about water not being cold enough - we use water coolers for drinking treated water. For bathing most of us prefer it a bit warm.

You say there is plenty of room - which to me makes it more above ground - they use below when there is no room in tight city lots to make it appear more open.

But the only answer that matters is the wife. You fail that test and heaven help you.

[kamalabob2]

I bought two 2000 liter Diamond Brand Green tree Sand Stone Series water tanks for clean water to use inside a two story home. They are at ground level in a "pump room" attached to a carport. I also had installed a 500 liter Hydroline Bladder Expansion Diaphragm Tank. When the electricity goes out, we still have water pressure inside both floors of our home. No leaks in those two 2000 liter plastic water tanks and it would seem they could be cleaned if I wanted. Now under the ground tanks are a different beast. I watched as two large 30,000 liter clean water tanks were installed last year in Buriram behind the Taweekit Shopping Center. They also have a serious booster pump to pull that water from the underground tanks to inside the new part of that shopping center. If you are in Buriram, you can be sure they do not plan to pull up those two tanks as they placed concrete over the top. Also in Buriram above ground, at surface level water tanks on normal concrete pads, water pumps, bladder expansion diaphragm tanks are in use at i-Mobile Stadium. They hid the various water tanks behind bushes and they do not seem unsightly in any manner to me. If the OP has hired a house builder who would come back to deal with water tank issues, years after that house is built he has hired a rare breed of house builder. In my experience and observation getting a typical house builder in Buriram to come back and solve roof leak issues is a great accomplishment the first year and nearly impossible after 12 months. The house builder who built the home I live in was wise to make water pumps, water tanks, a/c, kitchen counters NOT part of the contract and I used sub contractors who were far better trained in their specific fields. Those sub contractors, hired directly were responsive to "after the sales" service issues. The house builder "lost interest" after one year in any service issues.

[lopburi3]

the builder has quoted us a set price for the house, and this price will not alter whether we have the tank below, or above ground

After second read have fear this may be the reason for push to hide. If builder is planning on using normal blue tanks they allow light to enter and above round will soon become algae central if bleach not added and kept clean.

[cheeryble]

1. Do they make green?

2. How much tank for a modest one storey wih bit if a garden?

Edit:

I was talking about the composite type as in the sandstone knew above.

Guessing the blue plastic is lower grade.

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Edited April 10, 2014 by cheeryble

[lopburi3]

The blue type is the cheapest models and enough light gets into it to make it a mess without something to kill the algae all the time. I know SS does not have this issue and understand the sandstone type models are also fine.

Size of tank depends on if you have reliable source of water and how much you use daily - for us it is two 1250 size plumbed together - use about 1,500 liters per day and supply is reliable (Bangkok) but talking 8 or 9 people most days.

[kamalabob2]

Not all "Blue plastic" tanks are created equal. Both Safe Brand and Diamond Brand sell blue tanks of certain "series" that are not prone to the issues of common blue tanks. They list the sunlight blocking layer on the label of some better series of blue water tanks. Any good water tank retailer can show you water tanks side by side and indicated the discount price including proper delivery and guaranteed installation at your home. The water tank brochures I have read make it clear about wall thickness, outlet size, warranty period so it is not difficult to compare name brand water tanks in Buriram or any province in Thailand.

[Issangeorge]

We have many power outages, especially in the rainy season (just about everyday) so our tank is on a water tower, if we have a power outage we still have water.

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[cheeryble]

Missus just calling mum who has a big ong at the house, it's like head height as I remember, to ask the price.

They could look very nice, but it occurs to me:

1. You gotta be able to get in to tighten up connections?

2. What are they made of.......can one cut holes in them so as to connect in series? (Or do they have the one outlet hole at the bottom pre-done at manufacture?)

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[lopburi3]

Are you asking about the clay jars? The SS and plastic/fiberglass tanks have fittings built in to attach taps/pipe/drain and point to fill. Believe most can be piped together as have done two SS tanks and have tap between them on the connecting pipe. As for the clay jars have never seen them used with any plumbing - just as storage for rain water normally.

A normal water tank is large enough at top to enter (maybe only the wife) and clean but normally can do that with just hose with SS tanks where drain from bottom center.

[Denim]

the builder guy who suggested we put them underground, who has worked here for 7 years and built 40 plus houses, says he has never heard of any problems occurring with the tank itself, and the requirement for it to be dug up

Your builder may be correct. Whilst looking at houses in the suburbs of Bangkok I viewed many estates built by Land And Home property developers. Almost all of their homes used underground water storage tanks with an access cover . Preuksa real estate however ( a bit down market from L&H ) tend to either not include a tank at all or where they do have it above ground ).

Perhaps there are leakages from time to time due to careless installation but then again I read in the papers a few years back of a child who was killed when a badly constructed water tower collapsed on him. Clearly ..............shit happens sometimes.

The are pros and cons to both options and one persons problems might be different from anothers. The concrete ring idea is good if you can find small enough tanks.

Another consideration is as follows.

Where will the water come from to fill the tanks ? Mains supply, well or rainwater.

If the tanks are to be filled with mains water it sometimes happens that the pressure can fall so low that it cannot rise to fill a high tank and it is illegal to place a pump between the mains and your storage.

I have experienced this myself. Whilst living on a Bangkok housing estate we noticed that the mains pressure was gradually decreasing. Over a period of about 6 weeks it fell so that the upstairs shower didn't work. The the upstairs tap and toilet wouldn't fill. Next it was the downstairs shower head until finally everyone on the village was reduced to the lowest tap in the downstairs bathrooms. This was the same for about a thousand homes, even those with above ground tanks. The only people who had water were either pumping illegally out of the mains or in one sole case , the local laundy had a large underground tank gravity fed.

Turned out to be a burst water main in the village that gradualy got worse and the local authority were slack in fixing it.

You pays your money and takes your choice.

Edited January 13, 2015 by Denim

[BillyBobThai]

Here in Chiang Mai, we have a well that's about 12 feet deep. In the 3 years we have been here, we have never had a problem with water.

We use the water for washing and cooking, drinking water is bottled. Back in the states I had used well water for everything for over 45 years with no health problems.

[Langsuan Man]

The reason the builders push the underground water tanks is because they save space, thus the developer is able to put more houses in a smaller space

Always question anything that a Thai builder tells you , especially if it concerns water, most of them still can't grasp the concept that water flows down hill

For those who are promoting underground tanks, how do you clean them ? Or do you really think that Thai water is so crystal clear that the tanks never need cleaning !