BY: Kathleen Ferris

Tempe Grease Coop: City & Businesses Clean Up Problem

Published Mar 31, 2014

So you stand there for a minute with the frying pan in your hand and think about sending bacon grease down your kitchen sink’s drain. What could it do to the plumbing? Imagine if you served hundreds, even thousands, of meals a day. Grease is a big water problem.

Tempe inspectors are discovering many grease traps are not being cleaned to the city’s standards. In response, the city has organized the Tempe Grease Cooperative, the first in the state and the only voluntary city-managed grease-trap-cleaning program in the country.

First, the good news about grease: Vats of oil left over from French fries and fried chicken are a valuable commodity. Restaurants sell the oil to companies that turn it into biodiesel fuel. The problem is the fats, oils and grease cleaned off dirty dishes and mopped off restaurant floors. It has to go somewhere. Small restaurants attach tanks to their sinks to trap the grease and large restaurants bury large tanks, most often under their parking lots, to intercept larger amounts of fats, oils and grease.

Restaurants are required to hire companies to regularly clean and dispose of the grease caught in those traps. If they are not cleaned well, grease can cause sewage fumes and sewage backup inside restaurants. Grease also can build up and clog sewer lines and the city must invest time and manpower to scrape it out. Sewage with a lot of grease mixed into it also is difficult to clean at a wastewater treatment plant.

The Tempe Grease Coop is the city’s response. This past fall the city selected three companies to clean the grease traps for all the restaurants that join the coop. The restaurants get a 15 percent discount off what they normally pay for the service and can hand over the responsibility of monitoring the quality of work to the city. Tempe is developing plans with Arizona State University researchers to study ways the grease caught in traps could be turned into a renewable biogas.

While that would be a happy ending, the question remains: What should you do with a frying pan full of bacon grease? Pour it into an empty milk carton and use a paper towel to clean the remainder of the grease in the pan. Then throw the carton and the towel into the trash. Find more information about water at .

For 45 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit .