Cleanse Water (Reversible)

With this spell, a wizard can cleanse any poison, saltiness, unpleasant taste, or the like from a body of water. He renders it potable and refreshing, cool even in full desert sun. The spell can remove alcohol (and dissolved drugs) from drinks, and turns magical potions into pure water. At higher levels, a wizard can cleanse an entire oasis.

Only one body of liquid can be cleansed at a time, however. A "body" is either the maximum area of effect, or the water within a container or boundary, whichever is smaller. For example, if the spell purifies a bucket of well water, it has no effect on the rest of the well.

Within a closed system, the results of this transformation are permanent; they don't end after any given duration. However, the spell does not prevent water from being polluted again in the future.

More poison can be added to a drink, for example. And a purified pool with an inlet that's polluted will soon be contaminated again. As a general rule, if a body of water has an inlet that is causing the pollution, the cleanliness lasts 1d6 days (this includes oases and wells).

If the spell is cast on a body of water too large to be cleansed entirely, the surrounding water soon taints the cleansed area again. For example, the wizard can cast the spell upon the ocean itself, creating a pure "pool" amidst the waves. In such a case, the affected area returns to its original state in 5d4 turns, (The wizard might be better served by casting the spell upon a barrel of water.)

The reverse of this spell is pollute water. It fouls a body of water with a class H ingested poison (onset in 1 to 4 hours, inflicting 20 points of damage to the drinker, half that if a successful save vs. poison is made). Likewise, pollute water can transform a magical potion into a class H poison. The polluted fluid has an acrid, pungent, oily smell; easily detected by those who can smell such things. Other magics may conceal its deadly nature, however.

The effects of pollute water are as permanent as those of its reverse. Small amounts of water are permanently tainted, while those with an incoming flow of fresh water clear in 1d6 days, Water within another, larger body returns to normal in 5d4 turns.

The poisoning of wells in civilized areas is regarded as treason throughout the cities and petty kingdoms of the Land of Fate. Those who engage in these activities are hunted down by the local authorities (or other adventurers).

The material component of both versions of this spell is a handful of sand, tainted with a drop of the caster's own blood. The wizard adds the tainted sand to the water he intends to alter. Casting either version drains 1d6 hit points from the wizard which he can regain only through natural healing (not magical).

Notes: Common in Arabian settings; otherwise very rare.