An electronic appliance includes a base defining a receiving opening, a cover pivoted to the base, and a locking mechanism slideably secured to the base next to a guide board for locking the cover to the base. The cover frame includes a ratchet teeth mechanism for engaging ratchet teeth of an insertable tongue. This produces an effluent fluid which can be returned through the outlet to the waste treatment system. Supervisors are also surveyed for information regarding their supervisory activities.