Unless absolutely certain your water supply is not contaminated, purify all water before using it for drinking, preparing food, brushing teeth, or washing dishes. If the water contains floating material, strain it through a clean cloth before purifying it. Following are three methods for ensuring safe water for emergency use. Cool before use and don't contaminate boiled water with dirty utensils, hands or containers. Add a pinch of salt to each quart of boiled water to improve the taste.
Household bleach is a good disinfectant for water.
Before using, check the label to be sure hypochlorite is the only active ingredient. Do not use bleach that contains soap. The amount of chlorine in bleach bottles is variable. The following table states the amount of product needed to purify water. The water should have a slight chlorine odor.