Is Kirkland Toilet Paper Bad for Septic Systems? What Costco Says and Shoppers Report

A bulk package of Kirkland Signature bath tissue sits on display. While the product is explicitly labeled as septic safe and works well for many standard households, plumbing professionals and shoppers share mixed reviews. Some homeowners report using it for years without issues, while others with sensitive or older systems caution that its thickness requires mindful usage to prevent potential blockages. Shutterstock.

Few household debates spark as much disagreement online as the safety of using bulk-buy toilet paper with private septic systems. Costco’s Kirkland Signature bath tissue is a fan-favorite staple found in garages and pantries across the country. It’s prized for its unbeatable value and plush feel. However, persistent rumors, viral social media posts, and warnings from various service technicians claim that like brands can wreak havoc on underground tanks and drain fields. Evaluating whether Kirkland bath tissue is genuinely hazardous requires looking past the online myths and examining how it actually performs.

What Costco and Industry Standards Maintain