Well, you made a project, purchased material: PNP pipes and fittings for the water supply, now you can proceed to installation.
To do this, you need to dig a ditch of the desired depth. In the case when the soil is very solid and it is very difficult to dig, experts advise using heat -insulating materials, which will protect your water supply from freezing. In the case of installation of a water supply for year -round use, for example, in a private house you can also resort to such a trick as the installation of special «heating» cables. But for the water supply in the country, such difficulties, of course, are useless.