As a Pole I heard this story so long ago it never occurred to me it even could be false. More: I assumed this is a standard procedure worldwide,(reply>), @Marek Siciński Clams not claims, he was looking for interesting clams.,(reply>), @Dex  the problem in  NYC is not the water the become from 120 miles away. This is a very good and clean water. The problem are the last few miles from the big pipelines to the small pipelines which go straight into the houses. About 50% are still old lead pipelines in NYC. Tap water is almost always contaminated in the last mile or in the home itself. In the large reservoirs where it is checked, it is still clean beforehand.,(reply>), @Marco Flores no. Certain jurisdictions have affordable and amazing testing water. NYC is infamous for having the best water in the country. Where I’m from in NJ, we have amazing water quality. Although I can drive a few miles to a town with bad water.,(reply>), @Swole Monkey "how will people who don’t have access to clams get them?" From farms. For example Danes grow them in Copenhagen.,(reply>), Others do it with fish. I know that for a fact. Its not the only controll of course, but if the fish die or behave strange you know something is wrong even between tests.