Contaminant

means any substance (including gases, liquids, solids or micro-organisms), energy (excluding noise) or heat, that either by itself or in combination with the same, similar or other substances, energy or heat, changes or is likely to change the physical, chemical or biological condition of water.

any solid, organisms, liquid or gas entering, or with the potential to enter and pollute, the potable water supply

<water supply> solid, liquid or gas entering, or with the potential to enter and pollute, a potable water supply