It also fucks up the main plumbing system right down to the water treatment facility and while there, it fucks that too.

If your taxes pay for wastewater management, you're fucking yourself up.
If you pay in addition to your taxes, you're fucking yourself up.
If you have your own septic tank, you're fucking yourself up.
If it flows to the river directly and you enjoy clean nature, you're fucking yourself up.
If it flows to the river directly and your taxes pay for nature maintenance, you're fucking yourself up.

Grease down the drain is fucking yourself up and you deserve it. You can not win with it unless you hate everything around you and don't pay taxes.. It will come back to bite you.