Interesting article but left me wondering why they don't use ¹H₂¹⁶O as the "standard water"? Surely you can make that (relatively) easily in a centrifuge by spinning out the lightest fraction of water.
This actually goes both ways; VSMOW itself was carefully made (by mixing in small amounts of water from other sources) to match the composition of an earlier reference water sample, NBS-1, which came from the Potomac River (one supposes it was a convenience sample). NBS-1 is no longer used as a point of reference, since everyone's agreed to use VSMOW instead, but the USGS sells it too.
The use case for this water is calibrating ultra-precision instruments. The use case for those instruments is measuring water with normal-ish isotope ratios.
Calibrating your ultra-precision instruments to a point far away from their normal use case is asking for trouble.