The local water authorities were interviewed on the local news last night. They found deliberate water contamination a needless worry. The sheer volume of water, time in the environment and standard treatment would make short work of any biological assaut. They did state a natural disaster could compromise quality in the actual pipes, so a household filter is still good insurance. If a physical disruption of supply is a concern, then stored water ( rotated frequently and/or treated) is an option. After the Northridge quake, only a few water systems were actually compromised. We had plenty just north in Ventura County. The deliveries of bottled water kept up with basic demand. It was rationed for consumption and basic hygiene. Unless transportation is actually disrupted ( ie flooding) , business will respond, be it water or gas masks.( I know what a lot of children will be wearing come Halloween this year.)<br><br>