Welcome to Southwestern Materials, Inc., On the Web.If you are looking for a cost effective way to seal your leaking pond, plug a leaking dam, or seal retention ponds and industrial lagoon areas; you have come to the right place.Seal it right with Sodium Bentonite!Sodium bentonite is a natural earthen sealant that is environmentally safe with no chemical additives. Southwestern Materials, Inc. is a Texas based supplier of Sodium Bentonite Clays.We provide processing, bagging and warehousing of high quality sodium bentonite clays.Some of the many uses for sodium bentonite are:sealing of earthen stock ponds, recreational ponds, retention ponds and golf course water hazards; coring of dam structures, water barrier cut off walls (slurry wall) and land fill liners.