But it is short-lived. Its service life is more than 15 years. Besides, it needs to be clean from silt every year. Additionally, when digging the well walls are strengthened, raising the risk of collapse.
Huduma maisha ya miaka 15. Aidha, ni lazima kuwa na kusafishwa kila mwaka kutoka sludge. Aidha wakati wa kuchimba shimo ya kuta si kraftigare, na kusababisha hatari ya kuanguka kwa dunia.