Thousands of old green carts in the city's waste and recycling department are going to be ... recycled.

Green carts, which are a key part of Calgary's new curbside composting program, are being rolled out quadrant by quadrant over the next few months.

Composting has been available since 2012 for people who live in four pilot project communities.

However, residents in Cougar Ridge, Southwood, Abbeydale and Brentwood have been using smaller carts than the ones in the new city-wide program.

green carts test pilot

The bins used in the city's pilot project were considerably smaller than the black and blue bins. Officials ultimately decided to use carts that are the same size as the garbage and recycling bins (CBC)

The smaller carts are being picked up by the city and replaced with the bigger ones.

That's a lot of carts

So, what do you do with 7,600 green carts?

The person in charge of the implementation of the green cart program, Philippa Wagner, said after the old carts are retrieved and washed, there's a plan to re-use them.

"We'll be using some within our own internal commercial operations for collecting food and yard waste from commercial customers," said Wagner. But most will wind up being re-sold through the city's surplus goods website.

Calgarians could theoretically buy one, but Wagner said it's also possible that a smaller municipality or private companies might be interested.

"We are asking $20 per cart and there are volume discounts if you want more than a hundred," said Wagner.

Change-over already happening

The older carts were picked up in Cougar Ridge earlier this week.

She said residents of Southwood are asked to put out their smaller carts Friday for their regular compost collection and then leave them out.

The carts will be re-possessed by the city on Saturday and residents will then see delivery of their bigger green cart.

The city's new $143-million composting facility, which is located at the Shepard landfill site, will be opening soon.

All Calgary households will have green carts by this fall.