A new recycling scheme using six bags and boxes has been branded "too complicated" and difficult for some older and disabled people.
Pembrokeshire council is rolling it out to 61,000 homes on Monday - but not everyone in the county will get them.
Marjorie Sullivan, 70, of Abercych, said she would have to climb 23 steps from her home with each bag then drive them to the main road to be collected.
The council said it meant people could "recycle more materials at home".
Mrs Sullivan lives on a steep lane and her husband is disabled - she claimed she was told by the council she would not get any assistance to collect waste and recycling from her house.
"I will not be able to carry all the boxes and bags, with the health issues I've got. I can't do it. Then we have to deliver them down to the bottom of the road," she said.
Councils in Wales must hit a 70% recycling target by 2024 or face fines of £200 per tonne. Pembrokeshire's was 62% in 2018-19.
Opposition councillor John Davies said: "It's clearly not going to work in the rural setting of the Preselis. It's a hugely complicated system. Six different processes to decipher what's recyclable.
"It's a huge change - 60,000 homes - and it will have an impact on every person in that home.
"I would have preferred to see a pilot scheme like some authorities have done to flush out the issues."
BBC Wales has been told 3,000 homes will be excluded from the new scheme for 18 months, including parts of Milford Haven and Pembroke.
The council said it was "never planned to roll out to all households at once".
The new recycling scheme has a sack for cardboard, a box for paper, a sack for plastic and metal packaging, a caddy for food waste, a box for glass and a clear bag for small batteries.
Recycling and food waste will be collected weekly, while rubbish bags will be picked up every three weeks - with a three-bag limit per house, although larger families can request additional bags.
At present, each home has a food caddy, a box for glass and a bag for plastics and tins, with black bags for non-recyclables collected every fortnight.
The council said the new scheme was in line with a Welsh Government blueprint already used by half of councils and it was "confident" people could adapt.
Persistent offenders who refuse to recycle face a fine of £150 - cut to £75 if paid within 10 days - but the council said this would be a last resort.
Pembrokeshire Council's environmental services chief Richard Brown said the authority had "declared a climate emergency".
It had had been "gearing up" for the changes for 18 months and was "ready".
"We need to hit our statutory targets," Mr Brown said.
He said that was 64% this year which would rise to 70% in three years' time.
"There are some significant financial penalties if we don't meet those targets," Mr Brown said. "Potentially, £200 a tonne for every tonne we're short. It could run into hundreds of thousands of pounds, if not millions."
He said if people were struggling they could get in touch.
"If the household doesn't have anybody that can assist with putting these out, we will offer assisted collections," he said.
"That's really where there's nobody else in that household or friendly neighbour to assist them.
"A lot of people don't need to put all their containers out every week. You can balance what you put out."