Half of what residents put in their black household waste bins should be recycled instead, a lead councillor has said.
Coun David Cunningham, cabinet member for environment, said food waste and plastics were being carted off to landfill instead of being recycled.
He said: "There's a major education exercise there. Half of what goes into our landfill bins wouldn't need to.
"People are putting in their wood, their food waste, their paper waste, and their plastic and bottles.
"If we get people to recycle more of the materials that they're actually putting into their landfill, it would make an even bigger impact."
Kingston Council officers reported in June that 35 per cent, or about 9,000 tonnes, of the borough's "residual" waste was food which could have been composted.
Only 15 percent of textiles which could have been recycled last year was correctly disposed of, a report said.
Kingston's recycling waste is collected weekly, and black bins are emptied every other week.
Coun Cunningham said Kingston Council was considering weekly collections as part of a renegotiated deal with contractors Veolia.
Deputy Lib Dem leader Coun Stephen Brister said: "It doesn't surprise me at all that there can be quite high levels of recyclable waste not being recycled.
"This is more expensive if we're pushing more waste into landfill."
The news comes as the Conservative Party is rumoured to be considering a place in its 2015 election manifesto for a pledge of weekly bin collections.
Coun Brister said weekly bin collections would be "a gimmick and a headline".
He added: "You're raising the cost of provision of waste disposal, and you're slightly undermining trying to improve your recycling rate."