EYEWITNESS NEWS (WBRE/WYOU) — Can I pour cooking grease down my sink? Can I flush tissues and napkins down the toilet?

Well according to one wastewater company, the answer to all those questions is no.

Aqua, a wastewater utility company that serves over 3 million Pennsylvanians, says pouring cooking grease and fat down your drains can actually cause blockages in the wastewater system. Aqua officials also said garbage disposals don’t keep fat and grease from getting in the pipes.

They stated backups occur when the previously stated items go down the drain as a liquid and solidify inside the pipes, sometimes forcing raw sewage back up into the home.

Additionally, Aqua said wipes, even ones labeled flushable, should be thrown out in the trash. Included in that list were napkins and tissues since they don’t completely break down, potentially causing backups in household plumbing.

For tips on keeping your wastewater flowing, watch this video created by Aqua.