Backfill Calculator - Watco Tanks

Backfill Calculator

Enter sieve analysis (% passing) to check against Watco Tanks manufacturer recommendations.

Choose Backfill:

Percent of pea gravel that is 3/4" (19mm) or smaller

Requirement: Pea gravel shall be no larger than 3/4-inch (19mm).

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Enter values and click Calculate.

NOTES FOR PEA GRAVEL

Percent passing 1/2" sieve (13 mm)

Requirement: 100% passing 1/2".

Percent passing #200 sieve (0.075 mm)

Requirement: ≤ 12% passing #200.

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Enter values and click Calculate.

NOTES FOR CRUSHED STONE

Percent passing 1/2" sieve (13 mm)

Requirement: 100% passing 1/2".

Percent passing #200 sieve (0.075 mm)

Requirement: ≤ 12% passing #200.

Ready
Enter values and click Calculate.

NOTES FOR CLEAN SAND

Percent passing 1/2" sieve (13 mm)

Requirement: 100% passing 1/2".

Percent passing #200 sieve (0.075 mm)

Requirement: ≤ 12% passing #200.

Ready
Enter values and click Calculate.

NOTES FOR NATURAL EARTHEN MATERIAL

CLSM compressive strength (psi)

Requirement: CLSM strength 70–150 psi.

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Enter values and click Calculate.

NOTES FOR FLOWABLE FILL (CLSM)