The main pool at the centre in Shrewsbury was closed in July 2022 after routine inspections spotted that corrosion had caused ceiling panels and ventilation units to become unsafe.
Other parts of the centre have remained open.
Shropshire Council says its intention is to allow the main pool to reopen as soon as possible.
A council spokesman said: "The £400,000 project is under way, with work to strip out damaged and eroded pipes and ducting from the airflow management system from the roof space over the pool, as well as unused light fittings, walkways and ceiling panels, scheduled to begin in April 2023."
Contractors are also scheduled, weather dependent, to replace glazing ahead of the strip out starting.
Once these two phases of the programme are completed, specialist contractors will be able to make progress on the installation of new ducting for the airflow management systems.
Councillor Rob Gittins, Shropshire Council’s cabinet member for culture and digital, said: “Finding the right contractors to carry out the work at The Quarry has been of vital importance to the successful completion of these works. We are confident we are now in a strong position to make some real progress.
“The strip out work has been booked in and the replacement glazing will all be in place ahead of that, which will then allow for the work to begin on installing the new ducting.
“This work is being carried out with the intention to reopen as soon as possible."
Councillor Gittins added: "We recognise there has been disappointment surrounding the closure of the main pool, but this is a complex project given the age of the building.
"Customer and staff safety are our priority and developing a successful programme has been at the centre of all our decisions."
He added: “The Quarry’s operating contractor, Shropshire Community Leisure Trust, has been very understanding and continued to run a full and varied programme of activities across the site’s other facilities, and we are grateful for that.
"We want to reopen the centre to its capacity just as much as they do.
“A key priority for Shropshire Council and its partners is to improve health and wellbeing at all stages of life, and increasing participation in physical activity across the community is crucial to this.”
The other swimming pools and fitness suite will remain open, and details of activities can be found at shropshireleisurecentres.com/the-quarry-swimming-fitness-centre