On May 3, 2012, a new law came into effect regarding the Regulations for the Prevention of Pollution from Ships and for Dangerous Chemicals.
It requires that all boats fitted with a toilet be equipped with either a holding tank or a marine sanitation device. It also outlines that portable toilets are permitted if well secured.
You can find more information about this on the Transport Canada website here.
Pump out facilities are located across Atlnatic Canada. You can find a list and map of the Default Pump Out Facilities here.