November 22, 2022

The kitchen is the heart of the home; laughter, conversation and satisfied appetites can be inspired by the home-cooked meal. Sadly, one less appealing culprit also may find its origin in the kitchen: fatbergs – giant globs of Fats, Oils and Grease (FOG) that build up and clog pipes.


Water that goes down the kitchen drain does not disappear; it travels through the sanitary sewer system to the wastewater treatment plant to be processed and cleaned and then is reused for purposes such as groundwater recharge and landscape irrigation or released back out into nature to join the water cycle once again.

Because sewer systems collect water from thousands of kitchens, the smallest amount of FOG can build up and eventually clog a pipe as the fats and grease cling to the inside of drains and sewer pipes.

Clogged pipes can lead to sewage overflows, a serious mood killer at a holiday soiree. Even worse, raw sewage can back up into homes or erupt through manholes, causing damage to homes and the environment. Grease is the cause of approximately 47% of blocked sewage overflows in the U.S. each year (Husain, etc. 2014).


Thankfully, greasy pipes need not be a by-product of enjoying the turkey dinner. Properly dispose of FOG found in food scraps, meat fats, lard, oil, butter, sauces, salad dressings and marinades, and dairy products using the following methods:

  1. Pour used cooking oil, bacon grease and other fat proMorguefileAlvimannducts into a disposable container, such as an empty coffee can or pasta sauce jar. Let the oil solidify at room temperature, and throw the container in the trash once the container is full.
  2. Scrape leftover food debris into the garbage or compost before washing. Place screens on the sink to catch debris.
  3. Wipe down grease on pots, pans, utensils and other kitchenware with a disposable, dry paper towel before washing. Discard the paper towel into the garbage.
  4. Use strainers over drains in the kitchen, bathroom and laundry room. Clean them frequently and dispose of everything that was caught into the trash.
  5. Filter and reuse large amounts of deep-frying oil.
  6. Recycle cooking oils at a grease disposal or environmental recycling site. Check with local water providers to see if they offer cooking oil recycling. For example, the City of Tempe Household Products Collection Center collects and recycles cooking oil from Tempe and Guadalupe residents.
  7. Refrigerate and reuse fat in place of lard for sautéing or for flavor.
  8. Spread the word. Share FOG tips with friends and neighborhoods about how to prevent sewage overflows.


Avoid sending food down the garbage disposal; garbage disposals only shred solids and do not prevent grease from food from building up again. 


Do not rely on hot water or a dishwasher to take care of FOG; the heat might melt the grease and push it further down the drain, but it will only solidify again once it cools, causing a build-up in the main sewer system. 


Do not use cleaning agents with degreasers. These degreasers temporarily break up the FOG, but the FOG rejoins into solids, causing a blockage further down the line.


Overall, to prevent sewer blockages, do not put anything other than water down the sink, and flush only human waste and toilet paper.



Encourage local restaurants to keep grease management a priority. In addition to properly disposing of solids, restaurants are required to install grease traps or interceptors, but these systems only work if they are properly sized, installed, maintained and cleaned. Restaurants with properly maintained systems avoid unsightly odors and plumbing backups. Click to learn more about how cities work with businesses to keep FOG out of the drains, and explore Tempe’s creative solution to partnering with businesses to manage grease.

Bottom line: Fats, oils and grease can be part of a healthy, water-wise lifestyle. Take a few moments after each family meal to prevent these dinner by-products from going down the drain. It is absolutely possible to have your turkey and eat it, too

Click here for more tips about how to use water wisely in the kitchen.


The City of Tempe Water Resources Department is one of 19 Water – Use It Wisely partners to offer water-saving advice and programs.