Management Profiles

Ownership & Executive Team

Richard Cristina, President
Richard has over 45 years of experience in the solid waste industry, and currently serves as President of GreenWaste Recovery, Inc. In the early 1970s, Richard was a co-founder of the first transfer and recycling center in Santa Clara Valley, and was a partner in both San Jose Disposal, Inc. and the Foothill Sanitation Company. Richard co-founded Zanker Road Resource Management, Ltd. in 1985, GreenWaste in 1991, and GreenTeam of San Jose in 1992. Richard is involved in all aspects of business development and is actively involved in various community, business, and non-profit organizations throughout the Bay Area.



Murray Hall, Vice President
Murray has over 30 years of experience in the solid waste industry, and currently serves as Vice President of GreenWaste Recovery, Inc. Along with Richard Cristina, Murray was a co-founder of Zanker Road Resource Management, Ltd. in 1985, GreenWaste in 1991, and GreenTeam of San Jose in 1992. Murray is a Certified Public Accountant and has worked in the financial industry his entire career. Murray is involved in all aspects of GreenWaste's financial operations and reporting, with particular interest in the development and application of emerging zero waste technology.



Frank Weigel, Secretary/Co-Chief Executive Officer
Frank has nearly 25 years of experience in the solid waste industry, and currently serves as both Secretary and Co-Chief Operating Officer of GreenWaste Recovery, Inc. Having spent his entire career in the solid waste industry, Frank has gained hands-on experience in all facets of GreenWaste’s collection and processing operations. His experience has proven invaluable in the optimization of operational efficiencies and in the reduction of GreenWaste’s carbon footprint. Frank currently oversees all of GreenWaste’s collection and processing operations.



Tracy Adams, Co-Chief Executive Officer
Tracy has more than 19 years of combined experience in the administration and operation of service-related industries, including 10 years in hotel operations and more than 9 years in the solid waste industry. Tracy is a graduate of Northwestern University with a B.S. in Education and Social Policy. Tracy is responsible for the direct administration and oversight of telecommunication, Internet Technology (IT) and network support, and database management. Tracy is also involved in the integration of all of GreenWaste’s’ accounting, customer service, operations, and outreach activities.


Dave Tilton, Chief Financial Officer
Dave has over 30 years of experience in both executive and technical roles in the financial management of large corporations including Asyst Technologies,, Paramount Parks, Six Flags Theme Parks and Time Warner Entertainment. Dave began working at GreenWaste in 2010 as Controller and became CFO in 2015. As CFO Dave is responsible for all aspects of the finance function at GreenWaste, including finance, accounting and compliance. Dave graduated from California State University at Los Angeles with a bachelor’s degree in Business Administration. He began his professional career as a CPA while working for Ernst and Young.



Management Team

Scott Scholz, General Manager, Palo Alto
Scott managed GreenWaste of Palo Alto's outreach department for six years, and became the General Manager in April 2015. The startup of Palo Alto contract involved the introduction of a compost program to the commercial sector and a significant expansion of the citywide recyclables program. Scott was instrumental in launching commercial food waste collection, resulting in a program that brings in over 11,000 tons of food waste per year. Scott previously served in a variety of roles at Navteq/Nokia Map Operations. He acted as the Vice President of Database Operations and the Vice President of Quality and Database Engineering. In these roles he helped design the Google Map interface. After departing Navteq, Mr. Scholz was the Vice President of Digital Map Operations (EU and NA) at TomTom. Scott holds a B.A. in Political Science and Business from San Jose State University and is a certified Project Management Professional (PMP).

Chris Siebenthall, Operations Manager, Palo Alto
Chris has over 20 years of experience working in the solid waste industry and began working for GreenWaste of Palo Alto in 2009. Chris has gained experience working as a collection driver, a route and training supervisor, and a landfill operations manager. Chris is responsible for all aspects of GreenWaste of Palo Alto’s operations, including collection, personnel management, safety and training programs, regulatory and contract compliance, and coordination with the City of Palo Alto and its citizens.



Eric Cissna, Environmental Outreach Manager, Palo Alto
Eric began working for GreenWaste of Palo Alto in 2016 as an Environmental Outreach Coordinator (EOC). In 2017, Eric transitioned to the role of Public Education Specialist and began working extensively on Zero Waste initiatives and education at Palo Alto schools. In the summer of 2018, Eric assumed the role of Environmental Outreach Manager for GreenWaste of Palo Alto. As the Outreach Manager, Eric coordinates the production of outreach and education publications, manages Outreach's relationship with residents, businesses, and the City, and oversees the City of Palo Alto’s Zero Waste Enforcement Program. Eric graduated from the University of California, Santa Cruz and holds a B.A. in Environmental Studies. Eric is a LEED Accredited Professional and TRUE Zero Waste Advisor.

Ereida Atayde, Customer Service Supervisor, Palo Alto
Ereida has had a comprehensive role in customer service for GreenWaste of Palo Alto since she began in 2009. Ms. Atayde oversees all Customer Service Department activity, which includes supervising Customer Service Representatives and receiving and resolving escalated calls. Ereida also works closely with the City of Palo Alto through coordinating and assisting with contractual reports and projects, as well as maintaining and managing relevant customer account data. Prior to joining GreenWaste of Palo Alto, Ereida provided customer service for GreenWaste Recovery, Inc. beginning in 2007. In 2008, Ereida received her Bachelor of Science in Social Work and Psychology from San Jose State University. 

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