Anything that poisons drinking water causes disease and death.
Chemicals percolating through the soil contaminate aquifers.
Dumped chemicals percolate through the soil.
Whatever contaminates aquifers poisons drinking water.
Dumped chemicals cause disease and death.

The following sorites are valid. Rewrite each sorites in standard form, using letters to represent the terms and reducing the number of terms whenever necessary. Then use Venn diagrams or the rules method to prove each one valid.