Circular No. 52 states “6.3 Accordingly, supply of water, other than those excluded from S. No. 99 of notification No. 2/2017-Central Tax (Rate) dated 28.06.2017, would attract GST at “NIL” rate. Therefore, it is clarified that supply of drinking water for public purposes, if it is not supplied in a sealed container, is exempt from GST.”
Source: a2ztaxcorp.com