Can a mosque be built over a soakage pit with raised corner pillars and precautions taken?

In our village there is a soakage pit. Whole of the drainage of the vicinity goes into it. May be refuse from human body like urine and faeces may also be entering it. It has a concrete slab over it. Can we construct a Masjid over it? If not, we can even afford to raise pillars on its corners and erect the mosque over the pillars above the ground level. The land in question (in which this soakage pit is located) belongs to a person and that person is ready to donate it.
Please let me know and the precautions we should take.