The Standard ATV-A-138 dated January 1990 has been revised and increased it considerably in the area of application. In addition the symbols used have been matched to those in Standard ATV-DVWK-A 198 published in April 2003. The recording of all surfaces providing runoff in one standard with notes on special regulations enables a comparable taking into account of the demands of soil and water pollution outside water protective zones. The Standard provides planners, owners of buildings and authorities with an overview of the currently known measures and facilities for the percolation of precipitation water which have proved themselves in practice.weiterlesen