Pour the two cups of water into a small pot and add the sliced ginger.

Bring to a boil and allow the water to reduce by half, about 20-30 minutes.

Allow the ginger mixture to cool to room temperature or slightly warmer, and then strain or scoop out the remaining ginger pieces.

Put the sugar into a large glass and add 1/4 to 1/2 cup of the ginger liquid.  Stir until the sugar is dissolved.

Add one cup of seltzer water to the ginger and sugar mixture and enjoy!