This is what I would recommend that you do. First of all - lab tests on water is very expensive and can range from $300 to $400 per test. Now that the city is admiting guilt, the EPA should become involved and they shoud do testing. But I wouldn't wait. Call around to various labs and find out how much tests would cost you. Ask for test specifically on
1) iron bacteria
2) nitrates
3) Cryptospridium
4) Giraldia
5) Coliform bacteria
these are the 5 troublemakers.