An estimated 350,000 people crowded into downtown Ottawa on Thursday for Canada Day. (CBC)

The National Capital Commission took several steps to make Canada Day environmentally friendly this year.

"We have taken measures to reduce greenhouse gas emissions at the source, and we will obtain and generate carbon credits to compensate for any net carbon impact," said NCC Vice-President Guy Laflamme.

He said he has re-allocated his Canada Day budget to cover the higher costs of going carbon neutral. The NCC will plant trees in Ottawa's greenbelt to offset the estimated amount of carbon left in the atmosphere by the celebrations.

More than 350,000 people jammed downtown Ottawa Thursday, and the usual vendors were there to serve them souvenirs and refreshments.

However, this year there were no Styrofoam cups or bottled water. Instead, free tap water was available, and filled the equivalent of 32,000 water bottles.

Paul Baker owns the company supplying the tap-water stands. He's only been at his business since the fall, but he said it's booming.

"It's like the plastic bag issue. It will take a little while to educate the public to bring your own bottle to a festival or an event. But once you get used to the idea, it's not an issue anymore," Baker said.

Sherry Smith of Toronto, who was in Ottawa for the festivities, said it's about time the celebration on Parliament Hill went green.

"I'm one of those old hippies. I think it should have happened a long time ago," she said.