In this quest you will get familiar with water sampling from the tap for radionuclide determinations, as well as necessary sample pre-treatment steps to ensure sample integrity and allow for accurate analysis of radionuclides.
After water is sampled from the tap, you will have to filter it through 0.45 um filter to remove any particulate mater from it. After filtration, you will need to acidify water sample. With that step you will prevent adsorption of radionuclides on the walls of container, as well as stabilize them to remain in soluble form sufficient time that you perform analysis.
How this is performed in real lab you can preview here.