complying with environmental laws or environmental remediation matters in 2019, nor do we anticipate that such expenditures will be material in 2020. As of December 31, 2019, we had 69 full-time employees, of which 11 are management, 22 are technical personnel, 17 are administrative personnel and 19 are field operations employees. Our employees are not covered under a collective bargaining agreement nor are any employees represented by a union. We consider all relations with our employees to be satisfactory. As of December 31, 2019, we leased office space as set forth in the following table: During 2019, aggregate rental payments for our office facilities totaled approximately $0.8 million. The following table sets forth, as of March 1, 2020, certain information regarding the executive officers of Earthstone: The following biographies describe the business experience of our executive officers: $^{ }$Frank A. Lodzinski  has served as our Chairman and Chief Executive Officer since December 2014. He also served as our President from December 2014 through April 2018. Previously, he served as President and Chief Executive Officer of Oak Valley Resources, LLC (“Oak Valley”) from its formation in December 2012 until the closing of its strategic combination with Earthstone in December 2014. Prior to his service with Oak Valley, Mr. Lodzinski was Chairman, President and Chief Executive Officer of GeoResources, Inc. from April 2007 until its merger with Halcón Resources Corporation (“Halcón”) in August 2012 and from September 2012 until December 2012 he conducted pre-formation activities for Oak Valley. He has over 45 years of oil and gas industry experience. In 1984, he formed Energy Resource Associates, Inc., which acquired management and controlling interests in oil and gas limited partnerships, joint ventures and producing properties. Certain partnerships were exchanged for common shares of Hampton Resources Corporation in 1992, which Mr. Lodzinski joined as a director and President. Hampton was sold in 1995 to Bellwether Exploration Company. In 1996, he formed Cliffwood Oil & Gas Corp. and in 1997, Cliffwood shareholders acquired a controlling interest in Texoil, Inc., where Mr. Lodzinski served as Chief Executive Officer and President. In 2001, Mr. Lodzinski was appointed Chief Executive Officer and President of AROC, Inc., to direct the restructuring and ultimate liquidation of that company. In 2003, AROC completed a monetization of oil and gas assets with an institutional investor and began a plan of liquidation in 2004. In 2004, Mr. Lodzinski formed Southern Bay Energy, LLC, the general partner of Southern Bay Oil & Gas, L.P., which acquired the residual assets of AROC, Inc., and he served as President of Southern Bay Energy, LLC upon its formation. The Southern Bay entities were merged into GeoResources in April 2007. Mr. Lodzinski has served as a director and member of the nominating and governance committee, audit committee and compensation committee of Yuma Energy, Inc. since April 2019 and previously served on its audit committee from September 2014 to October 2016 and its compensation committee from October 2016 to April 2019. He holds a BSBA degree in Accounting and Finance from Wayne State University in Detroit, Michigan. $^{ }$Robert J. Anderson is a petroleum engineer with over 30 years of diversified domestic and international oil and gas experience. He has served as our President since April 2018. From December 2014 through April 2018, he served as our Executive Vice President, Corporate Development and Engineering. Previously, he served in a similar capacity with Oak Valley from March 2013 until the closing of its strategic combination with the Company in December 2014. Prior to joining Oak Valley, he served from August 2012 to February 2013 as Executive Vice President and Chief Operating Officer of Halcón. Mr. Anderson was employed by GeoResources, Inc. from April 2007 until its merger with Halcón in August 2012, ultimately serving as a director and Executive Vice President, Chief Operating Officer - Northern Region. He was involved in the formation of Southern Bay Energy in September 19 Employees Office Leases Location Approximate Size Lease Expiration Date Intended Use The Woodlands, Texas 19,600 sq. ft. March 31, 2025 Office Midland, Texas 9,200 sq. ft. June 30, 2022 Office Name Age Position Frank A. Lodzinski 70  Chairman of the Board and Chief Executive Officer Robert J. Anderson 58 President Tony Oviedo 66  Executive Vice President, Accounting and Administration Mark Lumpkin, Jr. 46 Executive Vice President and Chief Financial Officer Steven C. Collins 55  Executive Vice President, Completions and Operations Timothy D. Merrifield 64 Executive Vice President, Geological and Geophysical Information about our Executive Officers