Ross Steenson is a senior specialist geologist with the San Francisco Bay Regional Water Quality Control Board and has worked for the agency since 2008. He has over 29 years of regulatory and professional experience in the investigation and cleanup of a wide variety of contaminated sites. In his current role, he provides technical support to staff, oversees cases, and develops and maintains agency guidance. His technical expertise includes vapor intrusion, contaminated groundwater discharges to surface water, contaminated sediment, and risk assessment. Since 2012, in a team of two, he maintains and updates the agency's Environmental Screening Levels, and is the lead for Total Petroleum Hydrocarbon screening levels. He was the lead author for preparing the agency's 2016 Petroleum Metabolites technical document. He earned a bachelor's of science degree in geology from The College of William and Mary in 1986 and a master's of science degree in geology from Miami University in 1991. He has been a certified California hydrogeologist since 1997.