The Executive Committee
The Executive Committee of the Association is comprised of the President, Vice-President, immediate Past-President, and Secretary-Treasurer. A Vice-President is elected annually from a slate of candidates by a majority vote of the State Voting Representatives. The Vice-President serves a one-year term before advancing to the role of President. At the conclusion of the President’s one-year term he/she advances to the position of immediate Past President for a one-year term. The Secretary-Treasurer position is elected to a two-year term by a majority vote of the Association’s State representatives.
Ms. Millie Garcia-Serrano was appointed Regional Director of the Massachusetts Department of Environmental Protection’s Southeast Regional Office in 2015, after serving as Deputy Regional Director for the Bureau of Waste Site Cleanup from 1998 to 2015. As Regional Director, Millie is responsible for the optimal management of the region’s operations, including pre-permitting, regulatory compliance assistance, enforcement program management, and municipal partnering and outreach. Millie also provides active support to a number of key MassDEP programs including drinking water, wastewater management, wetlands & waterways, air quality, asbestos, C&E, solid waste, brownfields, emergency response, state (c.21E) and federal site cleanup/auditing. Millie has 31 years of demonstrated public and private sector experience with focused expertise in environmental assessment and cleanup, risk characterization, brownfields redevelopment, environmental justice and natural resources damages.
Millie is a member of the Association for Environmental Health & Sciences Foundation’s (AEHS) Scientific Advisory Board tasked with providing advisory support to the Annual International Conference on Soils, Sediments, Water and Energy, and is a voting member of the AEHS Foundation’s Charlena Seymour Diversity Scholarship Committee. A native of San Juan, Puerto Rico, Millie has a Bachelor of Science in Biology from the University of South Alabama, College of Art & Sciences in Mobile, Alabama and a Master of Public Health from Boston University’s School of Medicine in Boston, Massachusetts.
Amy Brittain is the Risk Management & Groundwater Program Manager of the Land Protection Division of the Oklahoma Department of Environmental Quality. In this position she manages the Voluntary Cleanup and Chemical Reporting programs as well as coordinating groundwater and risk decision making across the division. Previously, Amy served for 14 years as the Section Manager for the Superfund Program working on Superfund Site Assessment projects, Superfund investigation and remediation projects, Formerly Used Defense Sites and CERCLA caliber state voluntary cleanup projects. Amy currently serves as a representative to the DEQ Information Technology Work Group, the State Geographic Information Council Data Sharing Workgroup, and DEQ Geographic Information System (GIS) Subcommittee. Amy is a graduate of the State of Oklahoma’s Certified Public Manager program (2016). Amy earned a B.S. in Geology from Virginia Tech (1999) and a M.S. in Geology from Oklahoma State University (2001).
Amy has been an active member of ASTSWMO since 2012. Previous positions held within ASTSWMO include as Remedial Action Focus Group Member, Vice Chair, and Chair (2012-2017) and Chair of the CERCLA and Brownfields Subcommittee (CaBS) from 2017 through 2020. She has been a contributor to ASTSWMO Superfund Position Papers and Work Products and a presenter and session moderator at many Association meetings. Amy represented ASTSWMO speaking at a U.S. House of Representatives Subcommittee Hearing (2016). Amy currently serves as the CaBS liaison to the ASTSWMO Contaminants of Emerging Concern Steering Committee.
Amy lives in Oklahoma City with her husband, Brad, of 17 years, whom she met at geological field camp in college, 15-year-old son, Ean and 7-year-old English bulldog, Gussie.
Tim Ratsep is the Director of the Delaware Department of Natural Resources and Environmental Control (DE-DNREC) Division of Waste and Hazardous Substance. He is responsible for Brownfields, Emergency Response, Federal Facilities, Hazardous Waste, Pre-Remedial, RCRA C, RCRA I, Recycling, Solid Waste, Superfund, and the Voluntary Cleanup programs within the State of Delaware. Tim became the Director in 2019 where he led a substantial reorganization of the Division to better serve customers by aligning limited resources to address cross-programmatic challenges. Tim joined the State in 2005 were he was the the Administrator of the the State cleanup programs and had oversight of the State Hazardous Substance Cleanup Act fund, which receives millions of dollars in State funding allocated to remedial programs. Prior to joining the State, Tim worked in the private sector on RCRA and CERCLA facilities throughout the United States. During his tenure with the State, Tim has initiated Lean management principals within the Section. He has been recognized in two Governor Team Excellence projects that utilized limited resources to meet the Department objectives. These projects resulted in tens of millions in savings for the State. Tim became active in ASTWMO in 2009 and joined the Remedial Action Focus group in 2013 working to become Vice-Chair and then Chair. Tim was honored to be elected in 2018 as Treasurer/Secretary and in 2020 was elected as vice president.
Tim received a Bachelor of Science in Environmental Soil Science from the University of Delaware and has a Master’s of Business Administration from Wilmington University. He is married to his grade school sweetheart and has two wonderful children.
April Webb started her environmental career as an engineer with the Kentucky Department for Environmental Protection in 1997, in the Division for Air Quality. Serving as a permit writer and later as the Supervisor of the Metallurgy Section, she oversaw permitting of various metal producing facilities. In 2003, April joined the Kentucky Division of Waste Management as the Hazardous Waste Permit Review Section Supervisor and in 2005, she was promoted to the Hazardous Waste Branch Manager. April’s primary responsibilities include overseeing the permitting and clean up of RCRA facilities, including the Blue Grass Army Depot destruction of nerve agents and the cleanup at the Paducah Gaseous Diffusion Plant. April is a graduate of the University of Kentucky with a B.S. in Chemical Engineering.
Members of the Board other than officers are elected by a State regional caucus and consist of one representative from each of the 10 EPA Regions. Each Board member serves an initial 3-year term and may serve a maximum of two full consecutive 3-year terms with the consent of their regional caucus. Board members are vested with the authority to carry out the affairs of the association and to exercise leadership in raising and exploring policy issues of potential concern to the membership.
Gabrielle Frigon (CT) – Contact
Gabrielle is the Division Director for the Waste Engineering and Enforcement Division and has oversight of Permitting and Enforcement for Solid and Hazardous Waste Facilities, Pesticides Management and Sustainable Materials Management. She has been with the CT Department of Energy and Environmental Protection for over 30 years and has worked in Remediation Division programs including Superfund Pre-Remedial, Potable Water and formal Enforcement. In 2007 Gabrielle joined the Waste Engineering and Enforcement Division supervising Solid and Hazardous Waste Permitting for the state and, for a few years concurrently supervised the Source Reduction and Recycling program and their efforts to advance the goals of the state-wide Solid Waste Management Plan. Starting in 2019 Gabrielle oversaw the work of the Office of Policy and Planning for the Bureau of Materials Management and Compliance Assurance and developed proposed legislation, policy and regulations. In October of 2020 she re-joined the Waste Engineering and Enforcement Division as the Assistant Division Director. In that role, Gabrielle oversaw the development of DEEP strategies and processes in support of the goals and objectives resulting from the Connecticut Coalition for Sustainable Materials Management as well as overseeing the work of the division. Gabrielle obtained her Bachelor of Science degree from St. John’s University, her Master’s degree from Duke University, and completed her Doctoral courses in Physics at New York University.
Wilmarie Rivera Otero (PR) – Contact
Wilmarie Rivera Otero is the Chief of the Underground Storage Tanks Division in the Water Quality Area in the Puerto Rico Department of Natural and Environmental Resources (DNRE) since November 2014. She earned a Bachelor of Science in Agriculture with concentration in Agronomy from the University of Puerto Rico, Mayagüez Campus, a Master of Science in Environmental Management with concentration in Environmental Risk Assessment and Management and completed curriculum courses leading towards a PhD at the Doctoral Program in Environmental Sciences at the Turabo University in Puerto Rico. Mrs. Rivera began working at the Puerto Rico Department of Agriculture for 5 years before working at Puerto Rico Environmental Quality Board (at present DNER) in 2003. From 2003 to 2008 worked as a Remedial Project Manager for the Superfund Division, and from 2008 through 2014 worked as the Federal Facilities Coordinator of PREQB in charge of all DoD investigations and cleanups conducted in Puerto Rico, including the islands of Vieques and Culebra.
Casey Korbini (WV) – Contact
Casey Korbini is the Deputy Director for Remediation Programs within the Division of Land Restoration at the West Virginia Department of Environmental Protection. She has been serving the citizens of West Virginia through her work at the agency for over eight years. In her current role, which she assumed in November 2017, she leads the Office of Environmental Remediation and its associated programs (Brownfields Assistance, Federal Facilities Restoration, Superfund, UECA-LUST, and Voluntary Remediation Programs). Casey holds a B.S. in Economics from the Wharton School at the University of Pennsylvania, where she concentrated in management and minored in environmental studies.
Holly Nelson (GA) – Contact
Holly Nelson is the Program Manager for Georgia EPD’s Hazardous Waste Management Program. This program regulates permitted hazardous waste treatment, storage, and disposal facilities, hazardous waste generators, and Department of Defense facilities. She earned her undergraduate degree from the University of Florida and started her career in environmental consulting where she worked primarily on projects related to site investigation and remediation.
After leaving consulting, Holly worked for Florida DEP in the Waste Cleanup Program, Georgia EPD in the UST Program, as an Environmental Manager for a private waste management company, and in 2019, returned to Georgia EPD’s Land Branch to work within the Hazardous Waste Management Program.
Christine Sieger (WI) – Contact
Christine Sieger started with the Wisconsin DNR’s Remediation and Redevelopment program in 2013 as the administrator of the Ready for Reuse loan and grant program. In 2014 she became the Brownfields and Outreach Section Chief, and in 2018 she took on the role of RR program director. Prior to joining DNR, Christine spent six years working for an entrepreneur, helping grow his business entities as a real estate development project manager, vice-president of real estate and president for their start-up confections company. In the first 11 years of her career, Christine worked for a national non-profit conservation organization including eight as executive director. Christine served on the board of directors of the American Hiking Society for five years and was a member of the Dane County (Wis.) Park Commission for 11 years. She has an M.S. in Urban and Regional Planning from UW – Madison
Yolunda Righteous (LA) – Contact
Yolunda Righteous has over 30 years of environmental experience in the field of waste permitting compliance, training, and project management. She is a Baton Rouge native with a Bachelor of Science Degree in Biology from Dillard University in New Orleans and began her career at the Louisiana Department of Environmental Quality (LDEQ) in 2001. I rejoined the LDEQ after working for nearly 15 years as the Waste Services Regulatory Director for Providence Engineering and Environmental Group LLC. In 2018, she earned a Law Degree from Southern University Law Center.
Currently, she serves as the Administrator of the Waste Permits Division of the LDEQ. Yolunda also serves as a Board Member of the Louisiana Solid Waste Association (LSWA) where she is the Conference Chair for the LSWA/LDEQ Louisiana Environmental Conference and Trade Fair.
Along with her current role as the Region 6 ASTSWMO Board Representative, Yolunda also serves as the Region 4 Director and a member of the Board of Directors for the Solid Waste Association of North America (SWANA).
Ruben Zamarripa (MO) – Contact
Ruben Zamarripa is the Chief of the Defense Sites Restoration Unit for the Missouri Department of Natural Resources. He has over thirty years of experience with environmental compliance and cleanup work in both the private and government sectors. Over the past twenty years his responsibilities include providing state regulatory oversight of environmental restoration projects at federal facilities and managing the Defense State Memorandum of Agreement/Cooperative of Agreement Program. Mr. Zamarripa represents Missouri on the Department of Defense National Formerly Used Defense Sites Forum Working Group comprised of seven states.
He has served as a team member, vice chair and chair of the ASTSWMO Federal Facilities Remediation and Reuse Focus Group and Federal Facilities Subcommittee. Mr. Zamarripa holds a Bachelor of Science degree in Environmental Health with an emphasis in Industrial Hygiene from Bowling Green State University, Ohio.
Suzanne Engels (WY) – Contact
Suzanne Engels is the Administrator of the Solid and Hazardous Waste Division of the Wyoming Department of Environmental Quality (DEQ). Alongside a talented staff, Suzanne regulates the storage, treatment, and disposal of municipal solid waste, industrial waste, and hazardous waste throughout Wyoming. Suzanne also oversees environmental remediation projects and manages the Underground Storage Tank Program, which addresses environmental impacts and returns contaminated properties to productive use.
Suzanne has served DEQ for the past 13 years in various roles within the Solid and Hazardous Waste Division and the Water Quality Division. Before joining the State of Wyoming, Suzanne worked for the Colorado Department of Public Health and Environment in the Water Quality Control Division and for the City of Englewood at the Littleton/Englewood Wastewater Treatment Plant. She also had short tours with the US Fish and Wildlife Service and the US EPA Region 8. Suzanne is active in ASTSWMO and was the Vice-Chair for the Solid Waste Disposal and Conversion Task Force within the Materials Management Subcommittee.
Suzanne earned her Bachelor of Science degree in Environmental Science and Computer Science from Regis University and her Master’s degree in Environmental Science and Engineering from the Colorado School of Mines. Suzanne resides in Cheyenne with her husband, three children, one dog, and six chickens. She enjoys all types of outdoor activities with her family including camping, canoeing, hiking, and fishing.
Lene Ichinotsubo (HI) – Contact
Lene Ichinotsubo is the Solid Waste Section Supervisor and currently the Acting Program Manager of the Solid and Hazardous Waste Branch of the Hawaii Department of Health. The Solid Waste Section oversees the design, operation and closure of solid waste management facilities and provides technical support in the development of state solid waste policies and programs; while, the Solid and Hazardous Waste Branch is home of the state’s solid waste, hazardous waste, and underground storage tank regulatory programs, and solid waste planning and statewide recycling programs, including the Hawaii Deposit Beverage Container Program.
Lene has over 32 years of environmental experience, beginning her career as an engineer in the private sector before moving to the Department of Health. Thus far, she has spent her entire 25-year career with Department of Health in the Solid and Hazardous Waste Branch, having experience in complaint and compliance inspections, enforcement, permitting, site assessment and remediation, and program management and planning. Lene has a master’s degree in engineering with an emphasis in water resources.
Christina Carpenter – Contact
Christina Carpenter is the Director of the Division of Environmental Health for the Alaska Department of Environmental Conservation. She provides strategic direction and leadership across multiple programs that comprise the Division, including food safety and sanitation, drinking water, solid waste, pesticides, the Office of the State Veterinarian, and Alaska’s Environmental Health Laboratory. The close relationship of these diverse programs demonstrates implementation of the “One Health” model in Alaska, a worldwide strategy which recognizes that human, animal and environmental health are intricately related and seeks to expand interdisciplinary collaborations and communications across these disciplines. Prior to her current position, Carpenter served as Operations Manager for the Division, and was responsible for guiding resource allocation across the Division’s programs to meet state-wide environmental health and protection goals. She holds both a master’s and bachelor’s degree in Business Administration.
Below is a List of ASTSWMO Past Presidents:
(years represent year of Presidency)
- 2022: Tim Ratsep (DE)
- 2021: Brent Everett (UT)
- 2020: Conchita Taitano (GU)
- 2019: Chip Crockett (AL)
- 2018: Ken Kloo (NJ)
- 2017: Mark de Bie (CA)
- 2016: Bonnie Buthker (OH)
- 2015: Mike Forbeck (PA)
- 2014: Ryan Benefield (AR)
- 2013: Jeffery Steers (VA)
- 2012: Ed Thamke (MT)
- 2011: Stephen A. Cobb (AL)
- 2010: Gary W. Baughman (CO)
- 2009: Peggy Harris (CA)
- 2008: Michael A. Savage (OH)
- 2007: Gerald W. Hardy (AL)
- 2006: Terrence Gray (RI)
- 2005: Stephen Hammond (NY)
- 2004: Jay Ringenberg (NE)
- 2003: Jennifer Kaduck (GA)
- 2002: Mark Giesfeldt (WI)
- 2001: David Finley (WY)
- 2000: Michael Kelly (NC)
- 1999: James Warner (MN)
- 1998: Howard Roitman (CO)
- 1997: Nicholas DiPasquale (DE)
- 1996: Mary Jean Yon (FL)
- 1995: Teresa Hay (IA)
- 1994: Daniel Eden (TX)
- 1993: Paul Didier (WI)
- 1992: Daniel Cooper (AL)
- 1991: Cheryl Koshuta (ID) & Daniel Cooper (AL)
- 1990: David Shelton (CO)
- 1989: William C. Child (IL)
- 1988: Bryan Dixon (TX)
- 1987: John Taylor (GA)
- 1986: Robert Malpass (SC) & William Cass (MA)
- 1985: Earl Tower (WA)
- 1984: Donald Lazarchik (PA)
- 1983: Richard Valentinetti (VT)
- 1982: Norman H. Nosenchuck (NY)
- 1981: Jack Carmichael (TX)
- 1974 – 1980: Moses McCall (GA)