It has modest concentrations of the flavor ions: Na, Mg, SO4, and Cl. The big problem is the alkalinity and calcium levels. In addition, the water source varies between surface water and groundwater. Without knowing where they are drawing from, it would be difficult to estimate what your tap water quality was. There are inexpensive aquarium test kits for Ca and alkalinity that could allow you to have a good idea of those levels. But is that testing and effort worth it to you? If it is, then a combination of RO dilution and acidification could provide good brewing water. If you just want to get on with it, then starting with RO water could be the easiest.