This lab is certified by the US Department of Environmental Protection (DEP) for drinking water and waste water analysis. They also provide pottery glaze leaching analyses (the water is kept in contact with the glaze for many days then analysed for trace levels of specific metals). Each suspected metal must be tested for and each entails a separate charge ($30-60 in this case). That means that testing one glaze for several metals could cost $200. How to make sense of these numbers? Google the term: "heavy metals drinking water standards", and click "Images". You will find many charts with lots of data (some of them show multiple sources). By searching pages for this term you will find books having detailed sections on each of the metals. This can seem overwhelming, but typically you are only interested on one metal in a specific glaze (often cobalt or manganese).