This technical note and the following data were developed from tests conducted by Graniterock’s Research Technical Services Group.

A major Bay Area utility company has written specifications concerning trench fill sand for its applications. The specifications establish acceptable limits concerning gradations, organic impurities, sand equivalents, pH, chloride content, sulfate content, and compaction.

110 Utility Sand can be used in a variety of applications including trenches for pipelines, fiber optic and electrical cables, fill behind retaining walls and under concrete slabs. Below you will find a typical utility's specification as well as Graniterock’s 110 Utility Trench Fill Sand results.

	Sieve		Typical Utility Specification		A.R. Wilson Quarry 110 Utility Sand
	½"		100		100
	#4		75–100		100
	#8		70–100		86
	#16		65–100		62
	#30		50–100		47
	#50		40–70		35
	#100		0–30		26
	#200		0–15		17.8

	Additional Criteria		Typical Utility Specification		A.R. Wilson Quarry 110 Utility Sand
	Organic Impurities		No Darker Than Plate 3		Lighter Than Plate 3
	Sand Equivalent		Equal to or > 20		70
	pH		Equal to or > 4.5, but < 9		7.8
	Chloride Content		< or Equal to 500 ppm		2.2
	Sulfate Content		Equal to or < 150 ppm		9.6
	Compaction		95%		95%
	(Maximum Dry Density is 108. 0 pcf with an optimum water content of 4.0%)

Sand color is a significant issue. The trench fill material must be lighter than normal soil color so that a sudden color change will alert contractors they are working in a utility trench. The goal is to avoid damage to buried utilities.

The correct pH and low level chloride and sulfate concentrations are extremely important to maintain the integrity of critical transmission components. The utility's goal is to minimize corrosive attack on their equipment to extend service life. Extended service life will reduce operating costs, reduce service interruptions and reduce the possibility of potential leaks.

110 Utility Sand is produced by crushing granite into the proper particle size distribution. To ensure optimum workability and compaction we suggest the contractor add water via water truck during installation.

For additional information, please contact the Aggregate Division Sales Office at 831.768.2380.