Alternative to Bentonite?

Depending on the geology of your site and the water tables, look at electrodes encased in concrete. This is one of the many methods described in the IEEE Green Book on Grounding Electrical Systems. Probably the best thing to do other than that is to talk to any vendor/contractors in the area that are doing Lightning protection. They will have a pretty good idea of what is required for the area. Concrete encased is about the simplest method outside of standard driven rods. Hope this helps.

As this is not an issue in the subsea (cathodic protection) environment, I haven't had to commit such tidbits of trivia to memory... but I have seen numerous such threads on the NACE Corrosion Network among land-based pipeliners.

Go to the NACE website, and click the "Resources" links to get to the Online Community page. There you can sign-up for free, to gain access to experts all over the world. There's also an archive of previous discussions that can be searched.

A plethora of information there. Worth the dig...

Best wishes in your endeavors ~

From Sleepy,

We used to utilise Marconite as a filler to make concrete conductive.

There was a recent post which had details of where it could be obtained from.

My experience was as Systems Manager of the group that came up with the concept.

Designer: William (Bill) Hymers

Long term tests were conducted - essentially to produce conductive buildings for screening and lightning protection.

Good Luck

Sleepy

Dear friends

Please see following links to understand What is earthing in electrical system

http://picearthingtech.com/

http://blogs.siliconindia.com/picearthingtech

Regards

Raju