Rock County Health Department Janesville
County or city public health lab
3328 Us Highway 51 N, Janesville, WI 53547-1088
Certified drinking-water tests (1)
Bacteria- Total coliform and E. coli bacteria (Safe Drinking Water certification)
From the Wisconsin DNR list of certified bacteriological labs, checked 2026-11-01. This list covers bacteria only; ask the lab about nitrate, arsenic and other tests.
Listed as certified for drinking-water bacteria testing by the Wisconsin Department of Natural Resources (DNR) Laboratory Certification Program (state lab ID 404). Listing checked 2026-11-01. Some certified labs only test samples for their own business or community; call ahead to confirm they accept private well samples and to get a sample bottle.