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NSW, VIC & QLD delivery

High-Purity Sodium Bentonite

Typical montmorillonite >90%

Why Bentonite For Dam Sealing?

Sodium bentonite is a natural clay that swells to several times its original volume when wet. In a suitable, properly prepared and compacted soil treatment, it can reduce seepage from dams and ponds. See the product specification sheet for typical properties.

Our sodium bentonite has a typical montmorillonite content above 90% and a typical swell index of 7 to 16 mL/2 g, as stated in the product sheet. The swell index is a test value, not a dry-volume expansion ratio; product purity alone does not establish a suitable dam treatment.

How It Works →

Bentonite delivered to your property

Delivery across NSW, VIC and QLD. Tell us your bag quantity, delivery address and unloading arrangements so we can confirm your delivered quote.

Get a delivered quote
Estimate transport to your address

Transport estimates are indicative. We confirm the freight charge before accepting your order.

Bentonite Pro is a Big Ditch Dam Company

Bentonite Guides

Practical guidance on diagnosing dam leaks, sizing your order and applying sodium bentonite.

Frequently Asked Questions

How much bentonite do I need for my dam?

Bentonite Pro’s standard application rate is 30 kg/m². Measure the total area to be treated, including the floor and walls, and multiply by 30. For example, 600 m² requires 18,000 kg before any allowance. Confirm soil suitability, the leakage cause and the installation method before ordering.

Can I apply bentonite myself?

Some prepared-dam work can be undertaken with suitable equipment and advice. Our product is sodium bentonite fines. Choose the treatment method after a site assessment; pure and mixed blankets have different cover and compaction requirements. Read How It Works before starting.

How much does a bulk bag cost and how far does it go?

One 1.2 tonne bulk bag is $295 + GST, plus freight calculated to your address. At Bentonite Pro’s standard rate of 30 kg/m², one bag provides material for 40 m² before any allowance. See the delivered price guide for worked freight examples.

Do you deliver to rural areas?

Yes. We deliver by road freight to farms and job sites across NSW, VIC and QLD. Use the transport calculator for an indicative freight estimate, then request a delivered quote. We confirm freight before accepting an order.