I’m new to distilling but have 46 years in water treatment
ground water is most always higher in dissolved solids than surface water
most municipal water treatment plants draw from surface water that is high in suspended solids
both surface and ground water change seasonally
the main difference is municipal water treatment plants adjust the water before it leaves their facility and enters there distribution system
one must always assume that the quality of both sources will constantly change
the only way to address this is to treat at the point of use
If you want to remove this variable, carbon filter to remove organics followed by reverse osmosis or deionization then uv. Only uv after ro or di because uv only kills microorganisms if it can see through the water. When water is high in solids, both dissolved and suspended, the uv cannot penetrate