I just read your post and another’s. We just had our septic system pumped/cleaned 2 years ago. A couple months ago I started using Costco’s toilet paper. Someone warned me against Charmin because they said it does not break down fast enough. I started thinking about this change as Costco brand does feel “thicker” to me. We have been trying to unstop clogs for the last two weeks! I asked Costco through two separate emails if they had any customers complain about their tp being a problem for septic systems and all that they will reply is it is “septic safe.” Lots of things say that but it doesn’t make them true. Thanks for your info.