Hi, The problem will come ...

Hi,

The problem will come down to an economic analysis.

Is the turbidity issue, a feed problem or filtrate problem?

If turbidity is a feed problem, then pre-treatment is the only solution if you retain UF.

If the turbidity is in the filtrate, then this is a filter maintenance problem, with failed membranes leaking.

On the question of changing to gravity media filters from UF, you need to know what final water turbidity is acceptable.  UF will provide a better filtrate if it is maintained, but UF is a more intensive and higher maintenance process.  An advantage of UF is the land area required is significantly less.  Media filters require a large surface area.

Media filters are simpler in terms of operation and maintenance, but are more sensitive to the chemical dosing systems.  If putting in media filters, ensure that you provide filter-to-waste after the backwash to ensure that any particles trapped in the media after backwash do not make it to the water supply.

The decision comes down to money and other constraints.