@sun Most home filtering systems aren't there for safety purposes ... they don't promise to filter out disease-causing organisms. Those filtering systems are there to remove things that make the water taste bad.

Also, Irwindale CA has the worst water I've seen with the exception of a couple of places in LA and MS where the water was intermittently yellow with sulfur compounds. Irwindale was known for its rock quarries, and as of the 1980s, the water comes out looking like whole milk and after about ten minutes it looks like skim milk. The flavor is horrible. I expect it to overwhelm a Brita filter within 2-3 days.