“Every day, the City of Ottawa’s central water supply provides safe drinking water to approximately 865,000 residential, commercial, and industrial customers. Using the Ottawa River as its source, drinking water is treated at two purification plants and subsequently distributed through more than 3,000 kilometres of water mains before arriving at your tap. In rural areas, the City operates six groundwater well systems.” City of Ottawa.
The city of Ottawa has helpful information regarding your drinking water. You can find it on the City of Ottawa website.