Darkwing Duck

Bud Flood, spring water salesmen has been posioning his competitor's water in order to promote his own. Darkwing moves to stop him, but ends up sending him into a vat of the poisoned water. He has survived in a watery form, ""The Liquidator"". Now, the Liquidator has turned all of St. Canard's water hard. How will DW stop a criminal who isn't a solid?