Management Profiles

Ownership & Executive Team

Richard Cristina

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 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 involvement in various community, business and non-profit organizations throughout the Bay Area.

Murray Hall
Vice President

Mr. Hall has over 30 years 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 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, which has proven invaluable in the optimization of operational efficiencies and reduction of GreenWaste’s carbon footprint. Mr. Weigel currently oversees all GreenWaste’s collection and processing operations.

Don Dean
Chief Financial Officer

Mr. Dean has more than 13 years of direct experience in the financing and accounting of solid waste systems in California. Prior to coming to GreenWaste, Mr. Dean worked for more than 30 years in the transportation, distribution and manufacturing industries in various capacities including work as a Certified Public Accountant and Operations Director. Mr. Dean graduated from Washington State University with a B.A. in Business Administration and is responsible for all financial aspects of GreenWaste, including facility financing, equipment acquisitions and ongoing operations.

Tracy Adams
Chief Administrative Officer

Mr. Adams has more than 17 years combined experience in the administration and operation of service-related industries, including 10 years in hotel operations and more than 7 years in the solid waste industry. Mr. Adams is a graduate of Northwestern University with a BS 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.

Operations Team

Colin Beall
Collection Operations Manager

Mr. Beall has been in the solid waste industry for nearly 30 years with experience spanning the management of landfill and transfer station operations to all aspects of material collection operations.  After managing the Jamestown Landfill in California, Mr. Beall was Operations Manager for the Zanker Road Landfill and became Collection Operations Manager for GreenWaste in 1991. Mr. Beall is responsible for the management of all drivers, equipment, routing, mapping and audit procedures as well as the development of safety, equipment, and training programs.

Ricardo Lopez
GreenWaste MRF Operations Manager

Mr. Lopez has been with GreenWaste for more than 15 years, working as a sorter, collection vehicle operator, MRF supervisor, and most recently as MRF Operations Manager beginning in 2008. Mr. Lopez is responsible for the direct oversight and management of all aspects of the GreenWaste MRF operations including the supervision of staff, commodity management, material hauling and transport, and safety reports. Mr. Lopez also oversees all contract compliance aspects of the MRF including transportation, allocation, and tracking of all recyclable materials and solid waste processed at the MRF.

Jim Moresco
General Manager, Santa Cruz Operation

Mr. Moresco is a third-generation garbageman having worked in the industry since 1970 and with GreenWaste since 2007. Mr. Moresco’s family began providing garbage services in Watsonville in 1926, continued to expand their service area and ultimately sold their operation in 1992. When GreenWaste won the contracts for Scotts Valley and Capitola and Unincorporated Santa Cruz County, Mr. Moresco continued as General Manager. Mr. Moresco has extensive hands-on experience in every facet of the garbage and recycling industry including collection, transfer and processing operations. 

Chris Siebenthall
General Manager, Palo Alto

Mr. Siebenthall has nearly 20 years experience working in the solid waste industry and began working for GreenWaste of Palo Alto in 2009. Mr. Siebenthall has gained experience working as a collection driver, a route and training supervisor, a landfill operations manager and most recently as General Manager for GreenWaste of Palo Alto. Mr. Siebenthall 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.

Management Team

Valerie Chavez
Customer Service Manager

Mrs. Chavez has been with GreenWaste for over 14 years and has extensive experience in general office management and the direct oversight and supervision of GreenWaste’s Customer Service Department. Mrs. Chavez brings an expertise and level of professionalism that enhances GreenWaste's ability to effectively communicate with our customer base and ensure and that they receive prompt and courteous responses to their billing and service inquiries. Mrs. Chavez is also responsible for contract compliance aspects of our collection and processing operations and reporting to the various jurisdictions we serve.

Emily Hanson
Director of Business Development and Communications

Ms. Hanson began working with GreenWaste in 2008, having gained previous experience in the integrated management of projects, programs, finances, contracts and personnel as the Executive Director for two non-profit organizations. Ms. Hanson is responsible for all aspects of business development including community and government relations, bidding and negotiating contracts, choreographing operational transitions and developing dynamic public education programs. Ms. Hanson received a B.A. in Politics and a B.A. in Environmental Studies from the University of California at Santa Cruz.

Barry Cristina
Human Resources/Special Projects Manager

Mr. Cristina has worked at GreenWaste for nearly ten years after spending almost 4 decades managing in the distribution and warehousing industry. Mr. Cristina has extensive experience in the management of accounting and personnel departments and as President of business operations.  After serving in the Army as an officer, Mr. Cristina received an Accounting degree with a minor in Philosophy from Santa Clara University. Since joining the GreenWaste team, Mr. Cristina’s bredth of experience has warranted his involvement in various capacities and on many special projects for the company.

Michael Gross
Director of Sustainability

Mr. Gross has been with GreenWaste’s sister company Zanker Road Resource Management for nearly 25 years and in 2011 began work as the Director of Sustainability for GreenWaste.  Mr. Gross has expertise in all aspects of material marketing including the development of new and innovative markets for recycled products and incorporating sustainability into all aspects of GreenWaste and Zanker’s operations. Mr. Gross obtained a B.S. in Business Administration from the University of Phoenix and has published several articles in industry magazines on Zanker’s C&D recycling and composting operations.

Dave Tilton

Mr. Tilton began working at GreenWaste in 2010 after years as a financial executive with diverse experience in the Theme Park, High Tech and Distribution industries.  Mr. Tilton graduated from California State University at Los Angeles with a bachelor’s degree in Business Administration.  He began his professional career and became a CPA while working for Ernst and Young.  Mr. Tilton is responsible for the accounting functions at GreenWaste including general accounting, accounts payable, payroll, billing, accounts receivable, collections and various governmental reports including franchise fees and compliance.