Conwy County Borough Council has said moving from fortnightly to four-weekly residual household waste collection could save more than £550,000 a year.
Following a public consultation, officers have drawn up plans to boost recycling rates that have plateaued at 59%.
Welsh authorities have been given a 64% recycling target by 2019-20, rising to 70% by 2024-25. They face stiff penalties if targets are missed.
A report said more than half of household bin waste sent to landfill could be recycled, and that it currently costs around £2.9m a year to dispose of residual waste.
It said: “This level of loss of value and resources in unacceptable.”
At least three other Welsh councils – Bridgend, Torfaen and Ceredigion – have mooted four-weekly collections.
The report recognised the move could lead to resistance from residents. It said: “This will be mitigated through frequent and clear communication that explains why the council is making this change in service provision.
“The risk of following status quo, i.e. no change to refuse collection service, would have significant financial, economic, social and environmental implications for Conwy and is not a viable option. Statutory recycling targets will not be achieved without change.
“If Conwy fails to meet its statutory recycling target obligations in the lead-up to the final 70% recycling target set for 2025, it could incur fines of up to £200 for every tonne of waste landfilled or treated as residual waste, which the council can ill afford.”
The plans are being considered by a scrutiny committee and would need approval of the Cabinet Committee.
Most of the 22 Welsh councils undertake fortnightly residual collections. Blaenau Gwent, Powys and Gwenedd have implemented three-weekly collections for all or some selected areas.
Other authorities, such as Monmouthshire and Cardiff, have placed restrictions on the amount of residual waste collected.
According to WRAP, only two other councils in the UK, Falkirk and Bury, have so far chosen to move to three-weekly collections, although several more have put forward plans to follow suit.