Home Improvement Siding Kitchen Windows Vinyl Pools Patio Security 0285

Section 38 – Sewer and Storm Drain Construction

Pipe Cover Requirements

Pipe Material Type and Location

Minimum Cover Requirement

High Density Polyethylene (HDPE) - non traffic areas Twelve inches (12”) - top of pipe

High Density Polyethylene (HDPE) - for dia. to 36” in

Twelve inches (12”)

High Density Polyethylene (HDPE) - dia. 42” to 60” in

Twenty-four inches (24”)

Span/8 but not less than 12 inches

Span/3 but not less than twelve

Spiral Rib - Aluminum with spans less than or equal to

Span/2 but not less than twelve

Spiral Rib - Aluminum with spans greater than 72”

Span/3 but not less than thirty

Reinforced Concrete in unpaved areas and under

1/8 the diameter or rise (the

greater of) but not less than twelve

Reinforced Concrete under rigid pavements

A nine-inch (9”) space between

top of pipe and bottom of slab

consisting of compacted granular

fill shall be maintained at a

Cast-in-Place-Concrete-Pipes in paved areas

The Structural Section plus

twenty-four inches (24”)

Cast-in-Place-Concrete-Pipes in unpaved areas

Twenty-four inches (24”)

Polyvinyl Chloride - C900 and C905

Twelve inches (12”)

Polyvinyl Chloride - D2241 and D3034

Twenty-four inches (24”)

Note: All depths shown are for a minimum trench width equal to the outside diameter of

the pipe plus sixteen inches (16”) measured at the top of the pipe.

38-9 BACKFILLING PIPE TRENCHES

Backfill of all sewer and storm drain pipes shall conform to the requirements in Section 19,

“Trench Excavation, Bedding and Backfill”, of these Specifications. Bedding and backfill for

sanitary sewer pipes shall be in accordance with Standard Drawing 7-4 for sewer and Standard

Drawing 9-1 for storm drain.

38-10 TESTING OF PIPE

Unless otherwise specified in the Contract, after laying, backfilling, and compacting of sewer

and drain pipe, and before placing the aggregate base, the Contractor shall clean the pipe

system, test for obstructions and leakage, and perform the television inspection (TVI).

Obstruction or leakage tests for storm drain shall be performed when required by the

Contract or when visual inspection by television or lamping indicates that there may be

obstructions or leaks in the pipe.