Jump to main content or area navigation.

Contact EPA Pacific Southwest

Pacific Southwest, Region 9

Serving: Arizona, California, Hawaii, Nevada, Pacific Islands, Tribal Nations

Sustainable Infrastructure:
Speaker Biographies

August 7, 2007
8:30 am - 4:30 pm
Cal/EPA, Byron Sher Auditorium 2nd Floor
1001 l Street, Sacramento CA

Nick Arhontes

Director, Operations and Maintenance
Orange County Sanitation District

Nick Arhontes has over 30 years of experience with engineered systems in both the private and public sectors. His work in the private sector included the areas of product engineering, manufacturing supervision, project management, field sales, business development and management. His staff manages the successful operation and maintenance of numerous infrastructure systems owned by the OCSD. The service area is 471 square miles and serves a population of 2.4 million. Replacement value of the assets exceeds $5.6B and is growing annually.

Mr. Arhontes began his career with OCSD in 1988 as a staff engineer in the operations and maintenance department focusing primarily on civil and mechanical systems. In the mid-90’s he was in charge of the Facilities Maintenance and Collection Facilities O&M Divisions. He successfully led his staff through organizational change issues resulting in more outsourcing and successfully implemented regulatory compliance programs. He is proud of his staff’s accomplishments in learning and applying private sector approaches to solving public sector problems. OCSD is recognized nationally for its leadership role in working proactively with its satellite communities and regulators in achieving improved compliance and collection systems performance. Mr. Arhontes was an innovator and stimulator in moving OCSD towards advanced Asset Management. Return to Agenda

Richard W Atwater

CEO and GM, Inland Empire Utilities Agency

Richard Atwater is Chief Executive Officer and General Manager of the Inland Empire Utilities Agency. Inland Utilities Agency is located in San Bernardino County, California. The Agency is a member of the Metropolitan Water District and provides wholesale water and wastewater utility services to over 800,000 customers. The Chino Groundwater Basin is part of the Agency’s service area and developed the award winning Optimum Basin Management Plan with over $150 million in State and federal grant funding on a total capital investment of $625 million. During the past few years the Agency has won numerous awards from the USEPA, the State of California, and other organizations for its innovative planning and development of biosolids composting, renewable energy and water recycling projects, developed through an integrated water resources planning process.

Mr. Atwater is the only water agency manager in California to receive the prestigious Governor’s Award for Environmental and Economic Balance three times: Governor Pete Wilson (1995); Governor Gray Davis (2002); and Governor Arnold Schwarzenegger (2003). He has testified extensively before the U.S. Congress and the California Legislature on water policy issues. In 1994 Secretary of the Interior, Bruce Babbitt awarded Mr. Atwater the Conservation Service Award, the highest citizen award for natural resources management.

Mr. Atwater was a member of Governor Davis’ Drought Commission in 2001, the Governor’s Water Recycling Task Force in 2002, and the Governor’s Desalination Task Force in 2003. He served on the California Water Commission from 2002 through 2004. He has participated in policy formulation workshops and expert panels for the National Academy of Sciences, the Western Governors Association, the Western States Water Council, and the National Water Research Institute. Mr. Atwater has served on the Board of Directors of the Association of California Water Agencies, the Urban Water Institute and the Western Urban Water Coalition. He is currently President of the Southern California Alliance of Publicly Owned Treatment Works (SCAP), the WateReuse Association, and the Southern California Salinity Coalition. Return to Agenda

Top of page

Chuck Clarke

Director, Seattle Public Utilities

Chuck Clarke was appointed the Director of Seattle Public Utilities in January 2002. Prior to joining SPU, Clarke served as one of former Seattle Mayor Paul Schell’s two deputy mayors, responsible for issues and projects dealing with utilities, transportation and the environment. He is the former Regional Administrator for the Environmental Protection Agency, Region 10 and managed its operations in Alaska, Washington, Oregon and Idaho for six years. As Regional Administrator, he worked with community, business, environmental, tribal and local government leaders on issues ranging from endangered salmon to transportation and growth management.

Mr. Clarke has served in a variety of state jobs in Washington, including Director of the Department of Community Development and the Director of the Department of Ecology. He also served as Agency Director of the Vermont Agency of Natural Resources. Clarke grew up in Bremerton, Washington, and earned both a Bachelor of Arts degree and a Master’s degree in Business Administration from Pacific Lutheran University in Tacoma. He is a member of the Board of the Association of Metropolitan Water Agencies.

Top of page

Return to Agenda

Tam M Doduc

Chair, California State Water Resources Control Board

Tam Doduc serves for Governor Schwarzenegger as the Chair and fills the position of civil engineer on the State Water Resources Control Board. Ms. Doduc most recently served as Deputy Secretary at the California Environmental Protection Agency (Cal/EPA), where she directed the agency's environmental justice and external scientific peer review activities. She also coordinated various environmental quality initiatives, and provided general oversight of children environmental health programs.

Ms. Doduc began her career in 1989 as an environmental consultant with McLaren-Hart, Inc. She then joined the staff of the State Water Resources Control Board and, later, the California Air Resources Board. From 1998 to 2002, Ms.Doduc provided technical and business assistance to environmental technology developers and manufacturers, serving in the Office of Environmental Technology and, later, as Cal/EPA's Assistant Secretary for Technology Certification. From 2002 to 2004, Ms.Doduc served as Cal/EPA’s Assistant Secretary for Agriculture, Air and Chemical Programs. A licensed civil engineer, Ms. Doduc earned a Bachelor of Science in BioEngineering from the University of California at Berkeley, and a Master of Science in Civil Engineering from the California State University in Sacramento. She also earned a Master of Business Administration from the University of California at Berkeley. Return to Agenda

Top of page

Micheal F Gearhead

Director, Office of Water and Watersheds, U.S. EPA Region 10, Pacific Northwest

Micheal Gearheard has worked for the U.S. EPA, R10 since 1976 and has been the Director of the Office of Water and Watersheds since 2002. From 1994 to 2004 he was Associate Director, then Director of the Office of Environmental Cleanup which involved managing Superfund programs. Prior to that, he managed the region’s Waste Management Branch and EPA’s Oregon Operations Office. He started at EPA working in drinking water programs.

Mr. Gearheard graduated from the University of Washington in 1971 with a Bachelor of Science in Zoology and pursued further undergraduate and graduate study in Environmental Engineering at the University of California, Berkeley, Portland State University, and the University of Washington. Return to Agenda

Adel Hagekhalil

Division Manager, Wastewater Engineering Services Division Bureau of Sanitation, City of Los Angeles

Adel Hagekhalil is a registered civil engineer with the State of California. He has a Bachelor of Science degree and a Master of Science degree in Civil Engineering and over 18 years of experience in the area of civil and environmental engineering. Mr. Hagekhalil is currently a Division Manager with the City of Los Angeles Bureau of Sanitation where he is responsible for overall wastewater facilities advance planning and engineering activities. Under his direction, the City has just completed an award-winning 20-year integrated water resources plan (IRP) that relies on public participation and integrates water supply, water reuse, water conservation, and stormwater management with wastewater facilities planning through a regional watershed approach. He is managing the implementation of the IRP, the City’s collection system settlement agreement, the collection system condition assessment, and a variety of capital improvement planning efforts.

Mr. Hagekhalil has extensive experience in infrastructure assessment, planning, modeling, upgrading, and funding. He has published numerous technical papers, has received local, state and national awards, and has participated in various technical conferences and committees. He is currently a member of the Water Environment Federation’s (WEF) collection system committee, the chair of the California Collection System Collaborative Benchmarking Group, the Co-chair of the National Association of Clean Water Agencies’ (NACWA) Facility & Collection System Committee, and a member of the AWWA/WEF Qualserve steering committee. Return to Agenda

Top of page

Bennett Horenstein

Manager, Environmental Services, EBMUD

Mr. Horenstein is the Manager of Environmental Services at the East Bay Municipal Utility District where he is responsible for a range of regulatory and technical support functions in EBMUD’s Wastewater Department. He has over 20 years of experience in an array of wastewater operations, engineering and regulatory issues. He has published numerous technical papers, has received local, state and national awards, and has participated in various technical conferences and committees. He is currently a member of the Water Environment Federation’s (WEF) plant operations committee, the chair of the California Association of Sanitation Agencies (CASA) Water Committee, the Co-chair of the National Association of Clean Water Agencies’ (NACWA) Water Quality Committee, and the vice-chair of Tri-TAC (a statewide wastewater agency regulatory group).


Mr. Horenstein graduated from the University of Florida with a Bachelor of Science in Environmental Engineering and pursued graduate work in Environmental Studies at Loyola Marymount University and Vermont Law School. Mr. Horenstein is a Registered Civil Engineer in CA and a Grade V certified Wastewater and Water plant operator. He enjoys hiking and camping with his family and kayaking and swimming in San Francisco Bay. Return to Agenda

Top of page

Dr. Mark Horton

Director, California Department of Public Health

Dr. Mark Horton is the Director of the newly formed California Department of Public Health (CDPH) and has served as California’s State Public Health Officer since 2005. In this position, he is responsible for advising Governor Schwarzenegger on public health issues. Dr. Horton is a pediatrician and public health official with more than 30 years of experience. He previously served as the Deputy Agency Director and Health Officer for the County of Orange Health Care Agency from 1999 to 2005. Prior to that, he held several executive positions at San Diego Children's Hospital and Health Center.

For six years, Dr. Horton served as Director of Public Health for the State of Nebraska. In addition to other hospital administration positions and working as a pediatrician, Dr. Horton has served in several academic positions, including adjunct professor for the San Diego State University School of Public Health, faculty pediatrician for the University of Nebraska Medical Center, assistant professor for the Department of Pediatrics at the Creighton University School of Medicine, and assistant professor for the University of Nebraska School of Medicine. He is an active member of the medical and public health communities, serving as a member of many boards, committees and commissions.

Dr. Horton earned a Medical Doctorate degree and a Bachelor of Science degree from St. Louis University and holds a Master of Science in public health from the University of North Carolina, School of Public Health. He was an ambulatory pediatrics fellow at the Duke University Medical Center and a pediatric resident at Northwestern University Children's Memorial Hospital. Return to Agenda

Peter Ruffier

Top of page

Director, Wastewater Division, City of Eugene, Oregon

Peter Ruffier has overseen the operation and maintenance activities associated with wastewater treatment for the Eugene/Springfield metropolitan area since 1992. The regional treatment facilities include a 49 MGD water pollution control facility, a sludge management facility, a seasonal industrial waste management site, and 49 pump stations, serving a population of approximately 200,000 people. The Wastewater Division has a staff of 78 people, and was one of the first public wastewater treatment agencies in the United States to be registered as compliant with the International Standards Organization’s 14001 standard for environmental management systems. The Wastewater Division was also the first public wastewater agency to be accepted into the U.S. EPA’s Performance Track program, which recognizes excellent performance in pollution control activities.

Prior to his present position, Mr. Ruffier worked at the Madison Metropolitan Sewerage District in Madison, Wisconsin. He started as a research biologist with responsibility for water quality monitoring and the establishment of an effluent toxicity testing program. At the time of his departure, he was Director of Special Projects and served as project manager for a Superfund-listed site involving PCB contaminated sludge. Mr. Ruffier has also worked as Director of Technical Services for the national Association of Metropolitan Sewerage Agencies (AMSA) in Washington, DC, where he handled regulatory and legislative issues related to wastewater treatment and water quality programs affecting large municipal wastewater treatment agencies. He continues to be active in AMSA (now the National Association of Clean Water Agencies) as a member of various committees, including the Water Quality, Wet Weather Issues, and Competitive Management Committees.

Mr. Ruffier was recently appointed by AMSA as a U.S. delegate to the International Standards Organization (ISO) Technical Action Committee developing international standards for the management of water and wastewater utilities. He has been actively involved in a number of state and federal water quality programs and research projects. He is the Chair of the Water Environment Research Foundation’s Research Council, which develops and directs $5 million in water quality related research annually. Mr. Ruffier received a Bachelor Degree in Biology from Michigan State University in 1976 and a Masters Degree in Water Resources Management from the University of Wisconsin-Madison in 1978. Return to Agenda

Mary Snyder

Top of page

District Engineer, Sacramento Regional County Sanitation District (SRCSD)

Mary Snyder oversees the operations of both the SRCSD and County Sanitation District 1 (CSD-1). She also serves as the Director of the Sacramento County Department of Water Quality. A registered Civil Engineer, Snyder earned her Civil Engineering degree from California State University, Sacramento, in 1986.

Prior to her appointment as District Engineer in March 2006, Snyder served as manager of the collection system for both SRCSD and CSD-1. She has spent 15 years working at the treatment plant in construction, and operations and maintenance. Ms. Snyder oversaw the operation of CSD-1 as Chief of the Collections System Division. During her tenure as CSD-1's Chief, she implemented an aggressive sewer assessment, rehabilitation and construction program, promoted a number of public education and awareness programs, and worked to establish customer service levels and performance measurement systems for district activities. Return to Agenda

Alexis Strauss

Director, Water Division, U.S. EPA Region 9, Pacific Southwest

Alexis Strauss has served as the Director of EPA R9’s Water Division in San Francisco since 1994. For her Senior Executive Service rotational assignment, she served as the Assistant Regional Administrator and chief of staff for the Regional Administrator from October, 2002 to July, 2003. Ms. Strauss began her career at EPA in 1979 as a Presidential Management Intern. She has over 10 years experience in the hazardous waste and Superfund programs.

Ms. Strauss is the recipient of the EPA Excellence in Management Award and the Suzanne Olive Award for Management which recognizes inspirational leadership on diversity. Ms. Strauss received her Bachelor of Arts (1977) and Master of Arts (1979) degrees from the University of California at Los Angeles. At UCLA, she was the recipient of the Dean’s Award for Service to the school in 1979. Alexis was raised in South Africa and southern California. She lives in Piedmont, California, with her husband, son, and dog. She enjoys reading, gardening, camping and hiking with her family, and is a mediocre but devoted student of the piano. Return to Agenda

Diane Taniguchi-Dennis

Public Works Director, City of Albany

Diane Taniguchi-Dennis is the Public Works Director for the City of Albany, Oregon. She has broad-based professional experience in all areas of public works management programs for water, storm drainage, wastewater, and transportation infrastructure systems including planning and financing, capital improvement program development, engineering design and construction, operations and maintenance, and the development of public policy. Ms. Taniguchi-Dennis came to Albany as the Assistant Public Works Director in 1999 and became Director in 2003. Prior to that she worked ten years for the City of Salem, progressing from a civil engineering assistant designing capital improvement projects to plant engineer, facilities engineer, wastewater services manager, and Assistant Public Works Director. She started her career with CH2M Hill as a design engineer on water and wastewater treatment plant facilities.

Ms. Taniguchi-Dennis has served on several national advisory and focus groups concerning integrated utility management systems including the Environmental Management System for the National Biosolids Partnership, and Attributes of Well Managed Utilities. She also served on the American Water Works Association workgroup on implementing Triple Bottom Line for US water utilities and the Water Environment Federation Utility Management Editorial Board. She received a B.S. in Civil Engineering from Cornell University in Ithaca, New York and is currently attending the Atkinson Graduate School of Management at Willamette University in Salem, Oregon. She is also a licensed Professional Engineer in the State of Oregon. Return to Agenda

Enrique C Zaldivar

Top of page

Executive Officer, Bureau of Sanitation, City of Los Angeles

Enrique Zaldivar has been Executive Officer, Bureau of Sanitation since 2006. His role is much like that of a Chief Operating Officer, with oversight across the Bureau, including the Wastewater, Watershed and Solid Resources programs. Prior to his current position he was the Assistant Director in charge of Solid Resources for four years, where he oversaw the work of over 1100 employees in solid resources collection, landfill maintenance, facility construction and design, curbside and citywide recycling, private sector recycling coordination, and program development.

Mr. Zaldivar started his career with the City of Los Angeles in 1985, in the Bureau of Engineering where he worked as a design engineer on wastewater treatment plants and major sewer projects. In 1990 he was promoted to the Bureau of Sanitation’s Recycling Program, which was in its formative stage at the time. Over time, his project team made the City’s curbside recycling program one of the most successful in the nation. In 1997, Mr. Zaldivar was promoted to the operations side of the solid waste business, as Assistant Division Manager of the Collection Division. It was here where his passion grew for world-class service delivery in the solid resources environment, with no less than 750,000 customers to serve every week, and over 1.5 million annual tons of solid resources commodities to manage by recycling, processing, composting, mulching or disposal.

Mr. Zaldivar graduated from Cal Poly Pomona in 1985 with a degree in Civil Engineering. He has also done graduate studies at the same institution. He is active in several professional and trade organizations and has been a little league baseball manager. He coaches other sports as well. He and his wife Brenda have two boys, Enrique and Alonzo, and are now expecting a baby girl, due in September.

Return to Agenda

Top of page

Speaker Biographies (PDF) (6 pp, 57K, About PDF)

Jump to main content.