The operation and ordinary maintenance of both plants does not require skilled operators, but households should be trained to understand the system [32]. Both digesters should be fed every day
and digestate should be correctly managed, disposed or reused in agriculture as fertilizer [18]. De-sludging of accumulating solids in the bottom of reactors is required on exceptional basis only. Both
plants should also be regularly checked for biogas leakage in the reactor or pipeline. Plastic bags are susceptible to mechanical damage and have a short operational life, typically