Professor Gardner's research focuses on human impact on the environment, in the fields of sustainability science and engineering  He has specific expertise is in the field of contaminates--found in everything from drinking water and waste water to the air we breathe. These include soil contaminated with metals and non-polar organic compounds, as well as the leaching of industrial byproducts such as coal ash, solid waste incinerator ash, slags, and treated soils. He has worked to develop samplers for analyzing PFAS / PFOA compounds in soils and groundwater. He can also speak  broadly about PFAS and PFOA in drinking water, soils, wastes and wastewaters and their accumulation in organisms in the environment.