By Ont do you mean Canada? If so, folks here may have limited knowledge of Canadian electrical codes.

No, grounding to a water pipe probably isn't acceptable. You'd want to replace the cable with one that includes a ground all the way back to the service panel.

Thank you for the reply. My concern right now is whether this ground wire attached to the HW pipe could potentially electrocute someone touching a tap, having a shower or whatever if something were to go wrong with the circuit. Judging by the looks of this wire and connection it's been there for years. Until I can get an electrician in here should I disconnect this ground wire?

It is unlikely that I will research the subject, but memory tells me that the NEC (USA) at one time contained provisions for adding equipment grounding conductors to existing circuits by running a conductor from the outlet to a grounded cold water pipe. Obviously a non-metallic pipe is not grounded.

Not just any cold water pipe. The connection of the grounding pin on a receptacle needs to go back to "an accessible point on the grounding electrode system" which includes the first five feet of a metal cold water pipe.