Environmental Services Manager
City of Tempe, Arizona
Jazz, esp. Miles Davis.
What’s the #1 nemesis of city sewers? “FOG”—fats, oils, and grease, in large part from restaurants.
FOG flows into sewers through sinks and floor drains. City laws require restaurants to install grease traps and hire contractors to dispose of FOG. Otherwise, it hardens in pipes, constricts flows, and causes sewer overflows, costing cities millions of dollars.
Tempe’s regulatory program failed to effectively manage FOG from local restaurants, due to its lack of authority to regulate negligent FOG disposal companies.
In March 2014 the city helped formed the Tempe Grease Cooperative (TGC), a retailers’ group including restaurants, to manage FOG. TGC negotiated lower rates with third-party contractors to clean grease traps, saving restaurants 15% or more on FOG cleaning costs.
TGC tracks these waste haulers, with help from administrative software currently in development. Partner Arizona State University supplies students to help administer the program and serve as “grease ambassadors.” About 20% of restaurants are participating, and Tempe’s diverted 600,000 gallons of FOG annually.
Next, the city is considering turning FOG’s embedded energy content into methane gas, another energy resource.
Municipal procurement processes need to be as competitive as the private sector, allowing for speed and efficiency in contracting FOG services. Partner with neighbor cities to more effectively address the needs of restaurant chains regionally.
David manages 30 FTEs who support the city’s wastewater and drinking water programs, and is project leader of the TGC.
Born and raised in Washington, D.C., but moved west to attend the University of Texas (BS, ’88) and Ohio State University (MS, ’94). Relocated to Arizona in 1994, and has been working in wastewater for 22 years. With Tempe since 1999.
Has run four marathons, including the Marine Corps (DC) and NYC.