Siskiyou County Emergency Preparedness Guide - Water Treatment

If you suspect or know that your water is contaminated, you may treat the water by either boiling it or disinfecting it using household liquid bleach. If the water is abnormally cloudy, has an odor or other discoloration, you should consider it contaminated and treat as follows:

Boil
Boil the water vigorously for 3-5 minutes. Add one minute for each 1,000 feet of elevation.

Disinfect
Use household liquid bleach to treat water (Do not use scented, color safe, or bleaches with added cleaners).

Stir and let stand for 30 minutes. The water should have a slight chlorine odor. If it doesn’t, repeat the dosage and let stand for another 15 minutes before use.  

More information can be obtained from the EPA's - Emergency Disinfection of Drinking Water - PDF

Use
Individuals should plan for at least one gallon of water per person/dog per day for three days, for drinking and sanitation.