BIN collections, street cleaning and maintenance of parks will be handed over to a private company as two councils merge their services.
East Hampshire District Council and Winchester City Council have agreed to join up their environmental services departments.
The deal, the first of its kind in Hampshire, will save around £2m a year across the two authorities.
The saving will be used to help balance the books after both councils’ government grants were slashed by around a quarter this year.
Union bosses said theywere happy there had not been any compulsory redundancies, but said only time would tell if resources were being stretched too thinly.
The deal means that residents in places like Bishop’s Waltham, Denmead, Horndean, Clanfield and Rowlands Castle will soon share the same service for bin collections and grass cutting.
Biffa Waste Services Ltd will collect waste and recycling, while the grounds maintenance contract has been won by East Hampshire’s current contractor, The Landscape Group.
Brian Wood, Unison branch secretary, said: ‘It still remains to be seen whether the structure is sustainable with the amount of work.
‘It’s a leaner structure than it was before. There will be some waste taken out of the workload.
‘But if you have the same number of phone calls and there’s fewer people answering them, it’s an issue. It’s whether the council can come up with new ways of working.
‘If there is too much work and the customers are not getting the services they need, then management will need to get extra resources.’
The contract has been awarded for eight years, but it will be reviewed after one year to see how well it is working.
It is one of a number of shared services being adopted by councils.
Havant and East Hampshire councils have merged their senior management teams and will share parking enforcement by the end of the year – saving more than £700,000 annually across the two authorities.
The new environmental services scheme will start in October and some residents will be given new bin collection days.
Veolia currently provides bin collections for East Hampshire and Serco for Winchester, but both contracts will end.