Shagun has directed numerous federal Prevention of Significant Deterioration (PSD) and state New Source Review (NSR) projects chemical, petrochemical and batch chemical manufacturing plants. He has extensive experience in regulatory air dispersion modeling and has conducted numerous PSD, National Ambient Air Quality Standards (NAAQS) and increment modeling analyses in support of a PSD permit applications for a variety of chemical plants. Shagun has extensive experience in providing expert advisement to law firms in matters related to litigation.
Private sector clients rely on Shagun's experience regarding chemicals, oil and gas, refining, storage terminals, surface coating, and batch chemical manufacturing. Shagun has also assisted public sector clients including the Texas Commission on Environmental Quality (TCEQ), local governmental agencies such as North Central Texas Council of Governments (NCTCOG) and, industry groups such as the American Petroleum Institute (API). Shagun's areas of expertise include NSR permitting, air dispersion modeling and exposure assessment, emissions inventory development, use of optical technologies for emission inventory improvement and air compliance audits. Shagun has also worked with industry groups such as the API to provide comprehensive comments to the U.S. EPA on their Emissions Modeling Platform, particularly for refinery and petrochemical sources.
At both plant and regional levels, Shagun has helped develop and improve comprehensive air emission inventories. Some of these projects also include the use of optical technologies such as Solar Occultation Flus (SOF), Open-Path Fourier Transform Infrared (OP-FTIR) and Vertical Radial Plume Mapping (VRPM) to improve emission inventories. He is experienced in the use of wastewater emissions model Toxchem to estimate emissions from wastewater treatment plants at refineries and chemical plants.
Shagun serves on the Board of Affiliates for the Rice University Professional Science Master's Program within the Weiss School of Natural Resources. A member of the American Institute of Chemical Engineers and Air & Waste Management Association, Shagun has previously served on the board as Chair for the Gulf Coast Chapter, and has been on multiple Annual Conference committees.