2008-Jul-19 - Wooroloo - What happens when the sump pump fails during heavy rain
I arrived on site to install the last purlins, only to find the slab and surrounds flooded during the last heavy rains.

Even the well was covered in water - indicating that its sump pump had failed.

Fortunately I had partly reexposed the lid of the well recently when I was having slabs delivered (did not want to obstruct the well).

After half an hour of frantic digging I got the lid open to reveal water to the top.

I hurtled back home to pick up the 'spare' pump (one keeping the computer museum barn dry) and a lot of 40mm pressure pipe.

Back on site I started pumping out the well (and consequently a lot of the area around it)

Ross and Ian very kindly came and helped, particularly with extending the drop pipe

Eventually we pumped the well out completely and examined the existing pump

I had expected to find that the well had collapsed halfway down, but instead found that the riser pipe had disconnected from the pump body and that it was running continuously without effect.

The problem was caused by me using a wire pin to hold the piping together - this had rusted out

While I was standing there looking dazed and overwhelmed - Ross and Ian got on with reinstalling the pump at a much higher level (one metre down instead of three metres) with properly glued joints and a universal coupling.

The universal coupling will allow me to quickly substitute another pump should this one fail

After a couple of hours - the whole site had drained substantially

During the week Ross rang to tell me that the pump had failed again - the float arm switch seemed to be a bit intermittent - he jiggled it and it started off again

I think I will need to rig up a high quality mercury float switch and some way of having a second redundant pump for those cases where the main pump fails.

I also need a way to power the pumps off a generator when the mains fails for a long period

This all sounds rather fraught - but I am sure that these problems will ameliorate once I deal with the public road water running down my driveway and the site is covered with a waterproof building