My local sprouts growers filtered the water through rock and soil and then got salmonella and board of health citation. What is safe?

Salmonella. Salmonella is an organism transmitted by the fecal/oral route. Either the soil was contaminated with feces, or one of the handlers had salmonella in their GI tract and was not using appropriate sanitary techniques. Actually very little in life is completely safe. Minimize risks and be careful. Stay well.