*Perforated pipes are suitable for collectors with very limited space and particularly where there is no routine landscaping maintenance. However, adequate pretreatment such as grass swales, extended sump catchbasins, or prefabricated units must be provided. | *Perforated pipes are suitable for collectors with very limited space and particularly where there is no routine landscaping maintenance. However, adequate pretreatment such as grass swales, extended sump catchbasins, or prefabricated units must be provided. |