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Fats, Oils & Grease (FOG)

GREASE……really is a problem!

 Grease is “hydrophobic” which means it prefers to cling to surfaces that are free of water.

Large amounts of oil and grease in wastewater can cause sewer lines to clog, sewer lift station failures, wastewater treatment plant problems and environmental concerns. Grease builds from the top down in the sewer line while heavier debris collects on the bottom as the wastewater flows through the sewer pipe. Grease build-up restricts the flow of wastewater. Sometimes, grease layers will break off and create a downstream plug. Eventually, grease will lead to costly and dangerous backups. When sewer pipes get clogged:

  • Raw sewage overflows into streets, parks, onto property and into homes.
  • Sanitary sewer service is disrupted.
  • Residential, commercial, industrial, and institutional operations are affected.
  • Sanitary sewer operation and maintenance costs go up which in turn causes fees to go up.

Residual fats, oils, and grease (FOG) are by-products that food service establishments must constantly manage. Typically, FOG enters a facility’s plumbing system from washing dishes/pots, floor cleaning, and equipment cleaning.

Sanitary systems are NOT designed or equipped to handle the FOG that accumulates on the interior of the sewer collection system pipes. Over 30% of our 2000 sanitary sewer blockages were the result of FOG build-up from residential, institutional, and commercial sources.


How can you help?

  • Never pour oil or grease down the drain.
  • Do not use hot water to wash grease away.
  • Use a paper towel to wipe up small amounts of cooking oil and then throw the towel in the trash.
  • Scrape food scraps, oils, and grease from dishware and cooking equipment prior to washing to keep grease out of cleaning water.
  • Pour cooled grease into a can, let it solidify, and then put the can in the trash.
  • Recycle used fryer oil at household chemical waste facilities. For a list of such facilities, visit
  • Limit the use of home garbage disposals.
  • Put baskets/strainers in sink drains to catch food scraps.


Want more information?

Please contact Water Environment
Services at 503-742-4561 or