Sodium bentonite expands when wet, absorbing as much as several times its dry mass in water. Because of its excellent colloidal properties (see Odom ref below), it is often used in drilling mud for oil and gas wells and for geotechnical and environmental investigations.

Sodium Bentonite

Sodium bentonite is a natural sealant and is used for sealing stock and recreational ponds, dairy and sewage lagoons, and city landfills. It is also effective as a hole plug as well as for controlling dust on highways. Sodium bentonite is one of the "most effective low cost methods" of treating porous soils. It is so effective, that the Federal Government and most states require a liner of sodium bentonite or material comparable, to be used to seal toxic waste lagoons and abandoned water and oil wells. It is environmentally safe, because it contains no chemicals, no additives, nothing toxic.


How Does Sodium Bentonite Work?

Sodium bentonite swells 15-18 times its dry size when wetted by water.

Over several years of testing, Sodium bentonite has proven to be one of the most effective sealants on the market. The United States E.P.A. has ruled that all landfills and waste disposal sites must be lined to prevent the leaching of hazardous chemicals into the existing ground water to protect the environment. The fact that sodium bentonite swells many times its mass, then forms a strong water and chemical proof seal makes it an ideal, inexpensive, permanent, and easy to install liner. Sodium bentonite is environmentally friendly and safe to use.

Differences in "Bentonites"

There are several companies selling bentonite clay for various markets. Some of these companies are misrepresenting their product because the public they are selling to does not know the difference.

We at Sturgis Materials are trying to educate the public on using sodium bentonite as a pond sealant.

If you are considering using bentonite as a pond sealant, Please read on!

1. There are two types of Bentonite clay.

* One is a sodium bentonite. Sodium bentonite has a natural swelling ability and will maintain its swelling ability throughout its use.

* The other is a calcium bentonite. Calcium bentonite is a non-swelling bentonite. It will not swell without additives or chemicals. Calcium bentonite enhanced with additives will quickly lose its swell...It is short lived.

* It is the swelling ability of the sodium bentonite that enables this clay to bond with the soil to create an impenetrable liner in the soil.

2. Bentonites are mined clays.

The quality of the bentonite deposits will vary. Some deposits of Sodium Bentonite are very high quality swelling deposits, while others are not as good. Some of the best deposits are deep in the ground and will require many man-hours recovering this bentonite.

So a good quality sodium bentonite begins with a good deposit!