The initiative educates more than 800 children from St Pius, St Mary's and St Laurence's Primary schools and coincides with the 10th anniversary of Keep Australia Beautiful Week.

Ms Hagan spoke to students about what pollutants can be washed into the Macquarie River, such as oil, toxins and rubbish.

St Pius kindergarten student Lachlan Farr pretended to be a builder and put dirt through a sieve into a bowl of water, simulating the dirt washing into the drain and then the river.

He said it made "the river yucky" and we should try and have a "clean river".

Teacher Anne Giddings said the session was well received by the students.

"It's very visual and it's good for them to be involved and see it happening," she said.

"It's a great idea starting to get the younger generation aware of the environment at such a young age."

Ms Hagan said the campaign also provided schools with bright and colourful stickers to stick on their school bins to prompt people to dispose of their rubbish appropriately.

The stickers are the same as the ones found on riverside wheelie bins, as part of council's Do the right thing for our river campaign.

A collection of environmentally themed books will also be donated to the school library as a thank you for participating in the initiative.