Premium Sodium Bentonite Clay

Lock In
Your Water.

PondLock™ is a premium-grade Wyoming sodium bentonite clay engineered for pond sealing, dam repair, and water retention. ASTM tested with a Free Swell Index that exceeds NRCS standards by 36%.

PondLock™ — Premium Sodium Bentonite Clay
30 ml
Free Swell Index (ASTM D5890)
15X+
Expansion Capacity
CPS 520
Exceeds NRCS Standards
Wyoming
Sourced & Sun-Dried

The Science of
Sealing Water

PondLock™ is a naturally occurring sodium bentonite clay mined from premium deposits in Northeastern Wyoming. When exposed to water, the clay expands up to 15 times its dry volume, forcing its way into soil pores to form a dense, self-sealing barrier that stops water loss.

Unlike calcium bentonite or chemically treated clays, PondLock™ achieves its sealing properties through naturally high sodium content — no additives required.

Sun-Dried Processing

Never kiln-dried. Low-temperature processing preserves maximum swell capacity.

ASTM D5890 Tested

Lab-verified Free Swell Index of 30 ml — exceeding the NRCS CPS 520 threshold of 22 ml.

100% Natural & Safe

Safe for fish, livestock, irrigation, and swimming. No chemicals or additives.

Technical Specifications
30ml
Free Swell Index (ASTM D5890)
Clay TypeSodium Bentonite
SourceWyoming, USA
ProcessingSun-Dried
FormGranular (–8 Mesh)
Expansion15X+ Dry Volume
NRCS CPS 520Exceeds (≥22 ml)
AdditivesNone

Engineered to Seal

From farm ponds to municipal infrastructure, PondLock™ provides a proven, natural sealing solution across a wide range of applications.

Pond Construction & Sealing

Seal new ponds or repair leaks with the blanket method, mixed method, or targeted application. Rates from 2–6 lbs/sq ft based on soil type.

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Dam & Embankment Repair

Core trenches, embankment sealing, and leak repair for earthen dams. Bentonite mixed at 30% with native soil creates an impervious core.

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Landfill & Containment

Low-permeability barriers for landfills, waste lagoons, and containment systems. A natural, self-healing liner that meets regulatory standards.

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Lakes & Large Water Bodies

Bulk sack delivery for large-scale lake sealing. Ships in 2,000 and 3,000 lb sacks by LTL or full truckload.

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Lagoons & Water Treatment

Agricultural lagoons, wastewater ponds, and treatment facilities. A chemical-free liner that protects groundwater.

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Well Abandonment & Plugging

Granular clay for sealing abandoned wells, plugging drill holes, and sealing pipe penetrations in dams.

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Not All Bentonite
Is Created Equal

The quality of sodium bentonite varies dramatically by deposit, processing method, and handling. PondLock™ is sourced from premium Wyoming deposits and processed to preserve maximum performance.

01

Highest Swell Capacity

FSI of 30 ml (ASTM D5890) — among the highest commercially available. Higher swell means tighter seals and lower application rates.

02

Wyoming Source Deposit

Northeastern Wyoming — home to the world's highest-quality sodium bentonite. The mineralogy is unmatched by deposits found elsewhere.

03

Sun-Dried, Not Kiln-Dried

Kiln drying damages crystal structure and reduces swell capacity. PondLock™ is sun-dried to preserve full performance.

04

Exceeds NRCS Standards

Exceeds NRCS CPS 520 requirement of ≥22 ml by 36%. Your project meets or exceeds federal soil conservation specifications.

05

No Additives, Ever

Some products use chemical additives for short-term performance. PondLock™ achieves superior results through natural sodium content alone.

06

Expert Support

Backed by the Natural Waterscapes team — specialists in pond construction, leak diagnosis, and bentonite application.

Lab-Tested Proof
Free Swell Index comparison: Texas bentonite 12 ml vs PondLock 30 ml

2.5X More
Expansion Power

When tested side by side using ASTM D5890, PondLock™ achieves a Free Swell Index of 30 ml — more than 2.5 times the 12 ml result from typical Texas-sourced bentonite.

Typical Texas bentonite fails the NRCS CPS 520 minimum of 22 ml. PondLock™ exceeds it by 36%.

Texas Bentonite
12 ml
✗ Fails NRCS CPS 520 (≥22 ml)
PondLock™
30 ml
✓ Exceeds NRCS CPS 520 by 36%

Choose Your Size

Bags for small repairs and testing, or bulk sacks for full-scale projects. All products ship direct from Wyoming.

PondLock™ bulk sack with four lifting loops
PondLock™ Bulk Sack — Ready for Jobsite Delivery
25
Pound Bag
PondLock™ Granular

Small repairs, soil testing, spot treatments. Standard ground shipping.

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45
Pound Bag
PondLock™ Granular

Rate testing, small area treatment. Covers 9 sq ft at 6 lbs/sq ft.

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Popular
2,000
Pound Bulk Sack
PondLock™ Bulk

28 cu ft/sack. Bottom drawstring discharge. LTL freight.

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Bulk
3,000
Pound Bulk Sack
PondLock™ Bulk

42 cu ft/sack. FTL flatbed or LTL van. Four lifting loops.

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Product Overview
PondLock™ Product Tear Sheet

Specs, application rates, coverage design, package sizes, and NRCS compliance — all in a two-page PDF you can share with your team or contractor.

Download PDF

Real Results

Your sodium bentonite clay worked awesome! I had a specific area sucking water and soil right through the dam. We dug a trench with an excavator and mixed in just two 45 lb bags. A few days later the overflow is overflowing again without any significant rainfall.

Verified Customer
Dam Leak Repair

The Granular Sodium Bentonite Clay has fixed my leaking pond! The leak was around the concrete drain — so bad there was a cavity about four feet deep. The pond filled up and has been at its normal level for two weeks. No discernible drop.

Verified Customer
Drain Pipe Seal — 150 ft Diameter Pond

Ready to Lock In
Your Water?

Whether you're sealing a backyard pond or lining a 50-acre lake, our team can help calculate requirements, select the right method, and get PondLock™ delivered to your site.

(877) 493-7660 — Bulk orders & technical support
Request a Quote