This document is the N-12® HDPE (per AASHTO) Pipe for Agricultural Drainage Installation Guide. Description with backfill selection table provided.

The recommendations presented here detail how to install a dependable subsurface drainage or groundwater control system using ADS N-12 dual wall, recycled-content HDPE pipe manufactured to meet ASTM F2648. These installation practices are not recommended for sanitary or storm sewer applications, commercial applications, road crossings or installations where a higher level of performance is required. While performance requirements can differ depending on a project’s specific requirements, this guide is intended to address the common practices used in agricultural installations. For installation conditions outside not addressed in this document (poor soil conditions, high surface loads), please contact an ADS representative for further guidance.

Backfill Selection only uses soils meeting the ASTM classifications. The minimum required compaction level for the respective soil is dependent upon the expected fill height and the trench shape being cut. Reference the Trench Construction section of the installation guide for compaction level and allowable fill height recommendations.

Table 1 shows the acceptable soil classes for backfill & embedment through a soil description and soil classification for ASTM D2321 or ASTM D2487. Values for each soil type explained.

Trench construction is important because de-watering is necessary to maintain stability of backfill materials for a safe and effective installation. As with any pipe, groundwater or seasonal high water tables may impede installation. This section of the document explains proper trench installation in varying situations. It features instructions for V-Bottom (4”-8” diameter pipe) with detail, Rounded Trench Bottom (10”-60” diameter pipe) with dimension and fill height tables and Flat Trench Bottom (4”-60” diameter pipe) with detail and maximum fill height table.