<prompt> Proposed guideline values for Radioactivity in Drinking water isGross a activity 1.0 BqL and Gross b activity 10.0 BqLGross a activity 1.0 BqL and Gross b activity 0.1 BqLGross a activity 0.1 BqL and Gross b activity 1.0 BqLGross a activity 10 BqL and Gross b activity 1.0 BqL  <response>: Key guideline aspects of WHO recommended drinking water quality: Colour 15 true colour units TCUTurbidity 5 nephlometric turbidity units NTUpH: 6.5 8.5Total dissolved solids TDS 600 mglitreZero pathogenic microorganismsZero infectious virusesAbsence of pathogenic protozoa and infective stages of helminthesFluorine 1.5 ppm 0.5 0.8 ppm: Optimum levelNitrates 50 mglitreNitrites 3 mglitreGross alpha radiological activity 0.5 Bqlitre New Guideline WhOGross beta radiological activity 1.0 Bqlitre New Guideline WhO. 