I think I found what you're looking for:

www.ferc.fed.us

Once you get to the home page, click on the "gas" icon. From there, hit the 
link to the "FERC Gas Tariffs Page." Then it gives you a choice of viewing 
the tariffs in HTML or saving them to a different file. 

I wasn't quite sure how you wanted to review this information. The website is 
updated every 30 days, or so it said, so you may just want to keep it 
bookmarked and check it out whenever you need the information.

If I totally missed the mark, please let me know and I'll keep looking.