Environmental Health and Safety

Wastewater — Keeping Fats, Oils, and Grease (FOG) out of the Sewer System

Use the answers to the following questions to help prevent wastewater blockages and sewer overflows on campus and in your home.

Why is it important to keep fats, oils, and grease out of the sewer system?

Fats, oils and grease can create blockages in the sewer system, which can cause sanitary sewer manholes to overflow onto the campus and enter storm drains. This allows fats, oils and grease to contaminate local waters, and exposes people to untreated wastewater, which is a public-health hazard.

What can I do to keep fats, oils, and grease out of the sewer system?

Do not pour fats, oils, and grease down the drain. This is the most important thing you can do to prevent them from entering the sewer system, because the fats, oils, and grease poured down kitchen drains accumulate inside sewer pipes. As these substances build up, they restrict the flow in the pipe and can cause untreated wastewater to back up onto campus, resulting in high costs for cleanup and restoration. Thousands of dollars are spent on plumbing emergencies each year to deal with grease blockages and pump out grease traps and interceptors. These expenses can be significant.

How can I reduce fats, oils, and grease in my commercial kitchen?

  • Put oil and grease in covered collection containers.
  • Scrape food scraps from dishes into trash cans and garbage bags, and dispose of them properly. Avoid using the disposal/food grinder and make sure scraps get put in the garbage instead.
  • Remove oil and grease from dishes, pans, fryers and griddles. Remember: let it cool first before you skim, scrape or wipe off excess grease.
  • Rinse dishes with cold water before putting them in the dishwasher.
  • Cover kitchen sinks with catch baskets and empty into the garbage can as needed.
  • Cover each floor drain with a fine screen, and empty the screen into the garbage can as needed.
  • Use best management practices, such as those listed on the Let’s Tackle the Grease in This Kitchen poster. You may want to print the poster out and hang it in your kitchen to help remind you and your coworkers how to keep our sewer system clean and safe.