By Warren Tenney
Grease sent down drains in restaurant kitchens has plagued city sewer systems since they were built. The Tempe Grease Cooperative takes an artful step toward better controlling the ugly problem. The program saves money for the City of Tempe and its businesses and transforms a government regulation into a government benefit.
The Problem: Grease, oils and fats from thousands of restaurants collect in cities’ wastewater systems. It requires expensive maintenance to stop all that grease from building up and blocking sewer lines. All AMWUA cities work hard to help businesses keep fats, oils and grease out of wastewater systems. They also encourage residents to save their own plumbing and their cities’ wastewater systems by cooling grease and then putting it into the trash. A sewer line blocked by grease can cause sewage spills that are no fun to deal with. Once grease-rich sewage reaches a wastewater treatment plant it also is more difficult and costly to clean and re-use. AMWUA cities treat and re-use wastewater to irrigate turf, store underground and cool the Palo Verde Nuclear Generating Station.
It’s not the vats of oil left over in restaurants from French fries and fried chicken that create the problem. This is called “yellow” grease and is a valuable commodity picked up by vendors and used to create biofuels. The problem is “brown” grease cleaned off dirty dishes and mopped off restaurant floors. It has to go somewhere and state and city regulations work to keep it out of sewers. Small restaurants must attach tanks to their sinks to trap the grease. Larger restaurants usually bury tanks, most often under their parking lots, to intercept greater amounts of fats, oils and grease. Cities require restaurants to hire companies to regularly clean and dispose of grease caught in these traps. Tempe inspectors find too many traps are not cleaned often enough or not cleaned to city standards and allow too much grease to enter the sewer system. This causes tension among restaurants, cleaning companies and the city.
The Solution: The city decided it wanted to offer restaurants an alternative way to comply with city requirements and kicked off the voluntary Grease Cooperative three years ago. The city’s Grease Coop hires vendors on behalf of local restaurants to clean the restaurants’ grease traps. The Grease Coop offers additional services to power spray a restaurant’s sewer lines, make repairs to its grease trap when needed, and pick up its yellow grease to sell for biofuel production. Tempe gains because it knows the job is done right and can reduce the number of grease trap inspections and improve relations with busy restaurant owners. The restaurants that join the coop enjoy the benefits of an economy of scale – an average 15 to 20 percent reduction in the cost of hiring their own vendors. The coop also saves restaurant owners and managers time by taking over the responsibility of monitoring the vendors’ work. Three years later, 173 restaurants are in the cooperative.
The Challenges: Tempe has 1,000 restaurants but, right now, the city is not actively recruiting businesses to join the Grease Coop. Tempe is working to grow the program in a manageable way so it can maintain the quality of its service. It has two challenges. First, administrative data, such as scheduling, billing, payments and compliance, are now entered by hand into electronic spreadsheets. The city is soliciting bids through January for a new software program that will allow administrative data to be recorded with a few clicks on a website. Restaurants, vendors and the city would have access to the program. The city expects the administration of the Grease Coop to be fully electronic by early to mid 2018. Second, Tempe also needs time to find, vet and procure more vendors who will do a good job at the right price.
The Future: Tempe operates the only city-managed Grease Coop in the country. Cities in California, Texas and Iowa are building programs and Dublin, Ireland, just launched a pilot program with Tempe’s guidance. Tempe hopes to inspire a regional Grease Coop joined by neighboring cities. A regional program would reduce costs for cities and restaurants and generate enough brown grease to begin transforming it into biogas at wastewater treatment plants where it can be used as a power source for plants or compressed into vehicle fuel.
We’re not the only people who think the Grease Coop is beautiful. The Alliance for Innovation is a partnership of 350 cities as large as New York and as small as Yuma. Every year the Alliance recognizes the country’s most innovative programs and in 2016 Tempe’s Grease Cooperative received the Alliance’s highest award. This little program that solves an ugly problem has a pretty brilliant future. Here’s a video that will help you learn more about the Grease Coop.
For 48 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 www.amwua.org.