Management Profiles

Ownership & Executive Team

Richard Cristina, President
Mr. Cristina has over 45 years of experience in the solid waste industry, and currently serves as President of GreenWaste Recovery, Inc. In the early 1970s, Mr. Cristina 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. Mr. Cristina co-founded Zanker Road Resource Management, Ltd. in 1985, GreenWaste in 1991, and GreenTeam of San Jose in 1992. Mr. Cristina 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
Mr. Hall has over 30 years of experience in the solid waste industry, and currently serves as Vice President of GreenWaste Recovery, Inc. Along with Mr. Cristina, Mr. Hall was the co-founder of Zanker Road Resource Management, Ltd. in 1985, GreenWaste in 1991, and GreenTeam of San Jose in 1992. Mr. Hall is a Certified Public Accountant and has worked in the financial industry his entire career. Mr. Hall 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/Chief Operating Officer
Mr. Weigel has nearly 25 years of experience in the solid waste industry, and currently serves as both Secretary and Chief Operating Officer of GreenWaste Recovery, Inc. Having spent his entire career in the solid waste industry, Mr. Weigel 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. Mr. Weigel currently oversees all of GreenWaste’s collection and processing operations.


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.


Tracy Adams, Chief Administrative Officer
Mr. Adams 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. Mr. Adams is a graduate of Northwestern University with a B.S. in Education and Social Policy. Mr. Adams is responsible for the direct administration and oversight of telecommunication, Internet Technology (IT) and network support, and database management. Mr. Adams is also involved in the integration of all of GreenWaste’s’ accounting, customer service, operations, and outreach activities.


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.


Katelyn Lewis, Environmental Outreach Manager, Palo Alto
Katelyn joined GreenWaste of Palo Alto as an Outreach Coordinator in 2012.  Since then, she has assisted businesses, schools, and residents throughout Palo Alto in implementing waste reduction and sorting programs.  In 2015, Katelyn assumed the role of Outreach Manager -  coordinating the production of outreach and education publications and managing Outreach's relationship with residents, businesses, and the City. Katelyn graduated from Cal Poly, San Luis Obispo with a B.S. in City and Regional Planning and served as the Planning and Building Technician for the City of Atascadero. 

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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