For a basic test for bacteria the Laconia Water Dept used to do that; pick up a kit at their office. We have done that on the island to make sure that the UV purifier was doing its job. A call to the office and one could check if they still offer that service to the public.
http://www.city.laconia.nh.us/index....s/water-inside
For anything other than bacteria you have to use one of the labs already noted.