Do you foresee any difficulties during the experiment?
We do. There would be some contaminants that might not be seen as they are possibly soluble and might have similar properties to the other contaminants found in the water.
Would you advise DULL to re-purify the water for sale?
I would not advise DULL to purify the water as purifying a batch of water that are in this condition would take a lot of time and money, and it would be profitable if the company disposes of this batch of mineral water and produces another rather than use time and money to purify the water.