Concern: widespread practice of withdrawal and injection into wells under development of un-characterized surface waters obtained from streams, farm ponds, or rivers while drilling or boring drinking water wells contaminates  groundwater with materials (see pollutants), and/or pathological organisms (bacteriological, viral & parasitic) which could threaten public health on or adjacent to permit holder's property. 

Reference: "G. Water used during well construction shall be obtained from a suitable source or the well being constructed.  A suitable source means a pure water source, or, when a pure water source is not locally available, water taken from another source then disinfected using compounds meeting NSF/ANSI Standard 60 environmental specifications." 

Private sanitary standards do not meet requirements of Code citation.
Therefore it is recommended requirement for disinfection be specified. 

Example given:  12VAC5-630-430. Disinfection.