Where does the water in the foundations come from?

-“…Excuse me, we have water in the communal basement and we are worried, because it is affecting the building’s foundations and we don’t know where it is coming from!”….-

Yes, there is indeed water, and it is a serious to very serious defect that can affect the reinforcement of the building’s foundations, or even the reinforced slab or the reinforcement that was originally designed.

But where does that water come from? Or perhaps better to ask, what kind of water is it?, Is it from the municipal mains, where there is a fault? Is it sewage from a fault in a building or a nearby wastewater outlet? Perhaps from a nearby aquifer? Or, if we are close to the coast, from the sea’s own water table?

Knowing where it comes from is essential, and not only to focus the search for the leak and its repair, but also to know what legal action to bring, because the type of water will reveal its origin: it may come from the water distribution network (possibly a matter for the public authorities), from the water table (civil claim, architect), or be the responsibility of another building (civil claim).

In any event, and as a consequence of all this, given the evidence of the serious defects that have appeared, the Architect who drew up the Basic and Detailed Design should have taken the measures needed to prevent this serious defect, -which was foreseeable,- which is seriously compromising the stability of the building’s foundations and structure, since they were undoubtedly built without proper waterproofing, in view of the obvious damage that has occurred.

But how can you tell what kind of water it is, easily and quickly?

• Buy a syringe and a sterile cup from the chemist’s.
• Go down to the basement yourself, draw some water and put it in the sterile cup.
• The water in the basement and in the lift may come from the same place and be the same water, but it is not advisable to open the doors and go down into the lift pit without the involvement of specialist lift personnel.
• Have the water analysed. At a chemist’s or an analysis laboratory.
• They will give you one of these conclusions:

1. If there is little ammonia in the water, it can be concluded that it is not wastewater since the main source of ammonia contamination is wastewater.
2. Given the similar conductivity of the basement water and the mains water, and the value obtained (low compared with seawater), it can be concluded that the basement water does not come from the sea.
3. The presence of nitrates in the basement water but not in the public mains water may be because it is groundwater contaminated by waste discharges or by fertilising practices (organic or inorganic fertilisers).
4. The water hardness parameter (calcium and magnesium) measured in the basement water and the mains water may indicate that the water comes from the same aquifer, since it reflects the natural characteristics of the water.
5. But if the basement water has lower conductivity than the public mains water, it may be a rise in the water table due to seasonal rainfall”.
6. From which assessment it can clearly be deduced that the water flooding the basement in question is not seawater but water from the same aquifer, yet not drinking water, in other words, not from the public supply network, which is chlorinated.

From there, and with one of these conclusions, we are no longer in the dark: we know which way to go, and we assure you that we will find the party or parties responsible for the defect.

If you would like more information, and help from specialist experts, please get in touch with us. www.dpcon.es