"Fatbergs (the word is a portmanteau of fat and iceberg) form over time as items that can't be broken down are flushed or washed down drains instead of disposed

"Fatbergs (the word is a portmanteau of fat and iceberg) form over time as items that can't be broken down are flushed or washed down drains instead of disposed correctly" So both oils/fat (which don't break down rapidly) and all sorts of things that shouldn't be flushed.