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Granular Bentonite for Pond Sealing - 2,000 lb Bulk Sack

Ships Via Standard Truck Freight

Bulk discount rates

Below are the available bulk discount rates for each individual item when you purchase a certain amount

Buy 6 - 9 and pay only $953.50 each
Buy 10 - 21 and pay only $740.95 each
Buy 22 or above and pay only $564.23 each
  • Sodium bentonite for pond lining
  • How much bentonite do I need?
  • Sodium bentonite swells in contact with water to seal soil
  • Bulk pricing for full truck loads
  • Easy to handle bulk sacks of bentonite clay
  • 1 ton per bulk sack of sodium bentonite clay
  • Bentonite clay particle sizes
  • Pond sealing clay for clay liner
$1,175.00 - $1,475.00


Granular Sodium Bentonite Clay for ponds 

One 2,000 lb sack = 28 cubic feet = 1.04 cubic yards

Bentonite clay is a natural expanding clay sealant that when exposed to moisture can expand 15X or more creating a very effective pond sealant when applied correctly. 

Bentonite is packaged in bulk sacks with a bottom drawstring port for easy emptying and four lifting loops at the top of the sack.  Less than truck load quantities that ship via enclosed van trailer are palletized.  Full truck load quantities may ship via flatbed freight without pallets.  All bulk sacks have top lifting loops which slide over pallet forks for safe, stable handling.
Full Truck Load of granular bentonite = 22 - 2,000lb sacks = 44,000 pounds = 22 Tons  


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Bentonite for Pond Sealing FAQ

Sodium Bentonite Source

Our bentonite clay is provided in granular form directly from the processing facility in Northeastern Wyoming. 

Bentonite Clay Application Rates for pond/lake bottoms

To properly apply bentonite clay to seal a pond, the pond must be drained and the bentonite clay then incorporated into the soil of the pond bottom and sides. The application rate for bentonite ranges from 2 pounds to more than 6 pounds per square foot depending on the soil characteristics. For clayey and silty soils, 2 pounds per square foot MAY be sufficient. For sandy soils 4 pounds MAY be sufficient and for soil containing gravel and rock, in excess of 5 pounds will be required to obtain a seal. Once the bentonite is applied, the soil should be disk harrowed to mix the soil and bentonite and then compacted.

Alternatively, a continuous blanket of bentonite clay can be applied to the soil and then carefully covered with clean soil or sand to prevent the clay from mobilizing into the water column. Placing the bentonite in a confined layer is far more effective as it forces the clay into adjacent soil pores creating a more effective seal.

Detailed Sodium Bentonite Clay Application Instructions

For best results, test application rates with your soils by treating a small area at the anticipated bentonite clay application rate.  Drive a 12" or larger diameter smooth wall pipe at least 8" into the soil column.  Manually compact the soil within the pipe and fill with 18" or more of water.  Measure the rate of decline in the pipe and adjust application rate for your soils as needed.  45 lb pails of sodium bentonite are available for testing bentonite application rates or treating small areas.

Bentonite Clay Pond or Lake Dam Repair

For a leaking pond embankment, if the location of the leak has been identified, it may be possible to construct a core trench in the embankment to slow the leak. To install a core trench, excavate a minimum 12 inch wide trench to at least 3 feet below the pond bottom elevation. The trench should be located as far back from the pond edge as possible while still remaining on the flat top of the embankment.

The goal is to create an impervious core in the embankment which will not allow water to pass through. This impervious core can be created in a number of ways. Bentonite clay can be mixed with the excavated soil at a rate of 30% bentonite clay and 70% native soil. The material should be placed back in the trench and compacted with a trench roller, plate tamper, or excavator bucket in 6 inch lifts. 

Standard Freight shipping to lower 48 states is included in product price.

Lift gate service is additional.

Allow 7-10 days for freight carrier delivery.

Bentonite Specifications

Granular Bentonite particle size = -8" Mesh

All bentonite particles will pass through a 0.0937" opening.  As with any "minus mesh" screened product, all particles are smaller than the mesh opening.  This results in a gradient of particle sizes from the 0.0937" to finer powder that is ideal for blending with soil and compacting.  

Bentonite Swell Index = 30

Bentonite Percent Moisture = 16.6%

Aged Fann 600 = 34.0 (measure of viscosity)

pH = 7.75


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