Make less wordy

Hi!

Would some one have an idea how to make these sentences less wordy? (Especially the second part)

One of the reasons for this

is that the eastern part of the temple’s foundation

is being supported by artificially filled soil.

It was made after the completion of the comprehensive restoration in 1996,

in order to protect the whole church’s foundation

from the effect of corrosive ground waters.

It included the notch of the soil around the monument

to pack down a shallow foundation.

Clay was used as a water proofing material.

The problem - it has a potential of significant expansion.

The expansion and contraction of the soil over time

can weaken the support for foundation and

cause it to settle and crack the walls.

(Cracked foundations, floors and walls are typical types of damage done by swelling soils.)

Since that clay soils were filled long time ago - 27 years ago - it might have lost its capability

and has to be replaced.