The City of Ottawa has been fined $450,000 along with a surcharge of $112,000 for a massive spill of raw sewage in August 2006.

The city pleaded guilty last month to illegally dumping some 764 million litres of raw sewage into the Ottawa River.

City officials have blamed the spill on an antiquated sewer regulator that didn't close properly after a heavy rainfall.

City supervisor Jean-Pierre Boisseau was fired last May after he admitted to lying to senior staff about reporting the spill.

Two other employees have since been fired and a supervisor was suspended without pay.

The sentence was imposed Friday by Justice of the Peace Louisette Girault.