There are two steps to this process. First, find out how your water is treated, from your water provider. I tried to complete this step yesterday by going to the usually-active utilities website for my city. But the website was down. I tried again today. Still down. This is bad for the city.
The second step is finding a certified testing place to test the water that comes to your house. The pipes can add a great deal of contamination to our water. The three certified testing places in California are all at least a couple hundred miles from here. I do not see myself calling one of them for my situation. So I figure I will wait to get the info from the city utilities website. Chances are pretty good that the website will also include information on the types of pipes used in this city and what they can do to the water.
I did find another website, for a company that installed an ozone system for the city. I am excited that maybe this is what the city is using to treat water rather than chlorine, but I don't know until I get to the city itself. Of course I could call! But why?? I can wait. This city is very conscientious about water in particular so I expect to find a lot online when the site is back up.