Fortnightly rubbish collection by councils could soon become commonplace in Wales, a BBC survey has revealed.
Many landfill sites in Wales are full
Research by BBC Wales' Week In Week Out found half of councils already collect waste every two weeks, or plan to, and five others are thinking about it.
It is designed to encourage recycling. Households would be limited to one wheelie bin of rubbish per fortnight, with recycled waste collected weekly.
But Tory AM Lisa Francis said it could create "serious hygiene problems".
The assembly government has set targets on recycling for local authorities to meet in order to reduce the amount of rubbish being sent to landfill sites.
Councils have been asked to ensure 25% of rubbish is recycled by 2007 and 40% by 2010. Authorities that do not reach these targets will be fined.
Every year, 4m tonnes of rubbish is buried in Wales, but many landfill sites are now full.
Fortnightly collection of rubbish would be combined with "doorstep" collection of recycled waste, including paper, glass and tins.
Newport was one of the first councils in Wales to switch to limit householders to one wheelie bin of rubbish per fortnight - but two boxes of recycled waste are collected every week.
The authority said the move had increased recycling by over 40%, but some residents have objected to the scheme.
Mother-of-five Mandy Price, who fills over 20 bin bags a week and does not recycle any rubbish, said she could not cope with the restriction.
Newport Council has seen a 40% increase in recycling
She told Week In Week Out: "It's a pain really... I don't see why they just don't come once a week," adding: "You just put it in the bins, and you don't really think where it goes at all."
Newport council said it was necessary to put pressure on people to encourage them to recycle more.
The authority said it had not seen a significant increase in fly-tipping after starting the scheme - and the household rubbish that was dumped often contained items which could be recycled.
Friends of the Earth Cymru director Julian Rosser said he would like to see more councils encouraging recycling.
He said: "What we really want to see is for recycling to be made as easy as throwing away rubbish - a lot of people have no doorstep recycling at all.
"It's always a worry that people might be tempted to dump rubbish but I don't feel many people will need to do that... as people recycle more and more their bin bags will shrink."
Lisa Francis, a Mid and West Wales Conservative AM, said the current situation was "unsustainable and is damaging our beautiful environment".
But she said: "However, I am concerned that collecting rubbish once every two weeks could pose serious hygiene problems, with rubbish left for fester for long periods of time, especially around bank holidays.
"It is particularly concerning in university towns like Lampeter and Aberystwyth, as rubbish collection is already a serious issue when students go off on their end of term breaks.
"Many hotels, restaurants and other businesses do not have adequate storage for a fortnight's worth of commercial waste and nor should they."
Week In Week Out is on BBC One Wales on Tuesday 7 March at 2235 GMT.