prEN ISO 25177

This document specifies an analysing methodology for protecting potable water in potable water installations within and outside buildings but within premises from the risk of pollution by backflow of non-potable water and gives recommendations on the design, risk analysis, backflow prevention devices and their installation methods (see Figure 1 and Figure 2). This methodology is also intended to be used outside premises for all water systems connected to a potable water distribution system up to and including the point of use (see Figure 3). The product standards for the specific backflow prevention devices or arrangements are intended to be used in conjunction with this document. For the development of new devices or systems, this document is intended to be used as a reference to establish the necessary level of backflow protection.This document provides guidance on the description of soil in the field and its environmental context. It is applicable to natural, near-natural, urban and industrial sites. The soil observations and measurements can be made on a project site level, on a plot level, on layer or horizon level and on specific soil constituents.
It also provides guidance on how to describe layers of anthropogenic (artificial) material or layers that were not modified by pedogenic processes in the strict sense and how to describe coarse material of natural or artificial origin.
This document can be used in combination with other publications that provide guidance or requirements regarding specific aspects of soil observations and measurements.
NOTE 1 It might not be possible or necessary to record data under all the headings listed in Clause 4 to Clause 11.
NOTE 2 Overall guidance for presentation of information from soil surveys is given in ISO 15903 [2].
NOTE 3 The guidance provided assumes that sampling is done in accordance with ISO 18400.