Management Profiles

Executive Team

Richard Cristina, President
Rich has over 45 years of experience in the solid waste industry and currently serves as President of GreenWaste Recovery, Inc. In the early 1970s, Rich 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. Rich co-founded Zanker Road Resource Management, Ltd. in 1985, GreenWaste in 1991, and GreenTeam of San Jose in 1992. Rich 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 Rich, Murray was the 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 a particular interest in the development and application of emerging zero waste technology.


Frank Weigel, Co-Chief Executive Officer
Frank 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, 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.

Joshua Dingman, Corporate Controller
Joshua has over twenty years of experience in various accounting roles with several CPA firms and several privately held companies. He has over seven years of accounting experience in the solid waste industry including five years with Waste Management, Inc. in Oregon. Joshua began working at GreenWaste in 2015 as Corporate Controller and in that capacity is responsible for financial statement preparation and review, MRF management reporting, supervision of the accounting department, and managing the annual audit conducted by the Company’s outside audit firm. He graduated from San Jose State University with a bachelor’s degree in Accounting and began his professional career with the regional accounting firm Yergen and Meyer LLP.

Management Team

Jim MorescoGeneral Manager, Santa Cruz Operation 
Jim is a third-generation garbage man, having worked in the industry since 1970 and with GreenWaste since 2007. Jim'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, Capitola, and Unincorporated Santa Cruz County, Jim continued as General Manager. Jim has extensive hands-on experience in every facet of the garbage and recycling industry, including collection, transfer, and processing operations.


Scott Scholz, General Manager, GreenWaste of Palo Alto
Scott managed GreenWaste of Palo Alto outreach department for six years and became the General Manager in April 2015. Scott was instrumental in launching Palo Alto's 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, where he helped design the Google Map interface. After departing Navteq, Scott was the Vice President of Digital Map Operations at TomTom. Scott holds a B.A. in Political Science and Business from San Jose State University and is a certified Project Management Professional.

Omar Lopez, Collection Operations Manager, San Jose Operation
Omar has been with GreenWaste for over 15 years working as a sorter, collection vehicle operator, and a route supervisor. In February 2015, he became the assistant operations manager and most recently in June 2016 was promoted to Operations Manager for our San Jose division. Omar is responsible for the direct management of all our operations including contract compliance, routing, audit procedures, safety compliance, training, and management of drivers. His vast knowledge in every area of operations has allowed him to create and maintain a dynamic workforce and environment.

Ricardo Lopez, GreenWaste MRF Operations Manager
Ricardo has been with GreenWaste for more than 20 years, working as a sorter, collection vehicle operator, and MRF Supervisor. Ricardo became MRF Operations Manager in 2008. Ricardo 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. Ricardo also oversees all contract compliance aspects of the MRF, including transportation, allocation, and tracking of all recyclable materials and solid waste processed at the facility.

Emily Hanson, Director of Business Development and Communications
Emily 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. Emily 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. Emily received a B.A. in Politics and a B.A. in Environmental Studies from the University of California at Santa Cruz and is pursuing her J.D. from Santa Clara University, School of Law (exp. 2020).


Barry Cristina, Human Resources/Special Projects Manager
Barry has worked at GreenWaste for over 10 years after spending almost 4 decades managing in the distribution and warehousing industry. Barry 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, Barry received an Accounting degree with a minor in Philosophy from Santa Clara University. Since joining the GreenWaste team, Barry's breadth of experience has warranted his involvement in various capacities and on many special projects for the company.


Valerie Chavez, Customer Service Manager
Valerie has been with GreenWaste for over 17 years and has extensive experience in general office management and the direct oversight and supervision of GreenWaste’s Customer Service Department. Valerie brings an expertise and level of professionalism that enhances GreenWaste's ability to effectively communicate with customers and ensure that they receive prompt and courteous responses to their billing and service inquiries. Valerie is also responsible for contract compliance aspects of collection and processing operations, and for reporting to the various jurisdictions served by GreenWaste.

Sara TreatCustomer Service and Outreach Manager, Monterey Peninsula and Santa Cruz Operations
Sara began working at GreenWaste in 2010, transitioning from Customer Service to Outreach. Sara was promoted in 2015 to the Customer Service and Outreach Manager for GreenWaste’s Monterey Peninsula and Santa Cruz County operations. Sara is responsible for all aspects of both departments, including the development and implementation of GreenWaste's customer service and outreach programs, management and training of all customer service representatives and outreach coordinators, and compliance with all collection and processing contracts. Sara received a B.S. in Psychology from Portland State University and an M.A. in Negotiation, Conflict Resolution, and Peace Building from California State University, Dominguez Hills.  

Katelyn Lewis, Director of Sustainability and Strategy
Katelyn began working with GreenWaste in 2012, serving the GreenWaste of Palo Alto office in an outreach capacity. Katelyn has overseen and coordinated the implementation of public education and outreach programs, conversion to fully-automated collection routes, and expansion of collection agreements. In her current role, Katelyn is responsible for companywide sustainability practices, impactful community engagement, and the development of innovative practices and projects. Katelyn received a B.S. in City and Regional Planning from Cal Poly, San Luis Obispo.  




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