B08_Attach_02_North_Rim_Final_CDs_Volume_05_20261012_Part11.pdf

This document contains civil engineering design details for water utility infrastructure at North Rim, Grand Canyon National Park, prepared by HDR Engineering, Inc. in Denver, Colorado.

The drawings present technical specifications for trenching, pipeline installation, and valve systems serving the North Rim facility. Key details include single pipeline trench configurations with 3-inch to 9-inch minimum widths and various depths; shared pipeline trenches for multiple utility lines; concrete encasement specifications for bore exits; water line concrete encasement at drainage crossings; pipe anchor arrangements using grouted rock anchors with mechanical couplings and thrust anchors; high-tensile steel wire mesh boundary conditions; and modular wall construction with concrete decking and granular fill. The isolation valve vault design features 48-inch by 72-inch polymer concrete vaults containing Schedule 80 steel pipes, mechanical couplings, 4-inch ball valves, and blind flanges. All connections are specified as ANSI Class 900 flanged connections with restrictions on bolt torquing. The drawings include detailed cross-sections, plan views, and material specifications referencing applicable federal specifications for precast concrete and modular block construction. The documents are dated May 2026 and signed by registered professional engineer Nicholas J. LaFronz of Arizona, with design oversight by J. Glover and Matthew Gough.