Applying Site-Specific Bench-Scale Testing to Characterize Stormwater Pollutants and to Improve Advanced Filtration Systems

Date: Presented at StormCon 2024 in Reno, Nevada on August 28, 2024
Speakers: Chris Hsu, Blake Van Drimlen & Nate Hasal
Credits: 0.75 PDH / Approved for all Envirocert International, Inc. (ECI) Certifications: Approval #PDH-0042

In November 2018, the California State Water Resources Control Board amended the Industrial General Permit for Stormwater Discharges, integrating 36 Total Daily Maximum Loads (TMDLs). Since July 2020, this has led to numerous industrial sites in California undergoing the Exceedance Response Action (ERA) process, facing stricter TMDL Numeric Action Levels (TNALs) and Numeric Effluent Limits (NELs). Consequently, these sites are contemplating significant investments in advanced stormwater treatment to meet these new standards and return to baseline status, thereby avoiding mandatory penalties for NEL exceedances. This study by GSI Environmental (GSI) showcases how scientific methods are employed to identify and analyze stormwater pollutants, aiding facilities in developing strategies to achieve compliance and revert from ERA Level 1 or 2 to Baseline status. Additionally, a key aspect of the study involves experimental bench-scale testing. The study highlights the importance of understanding stormwater pollutant characteristics and exploring comprehensive compliance strategies. This involves installing both passive and active treatment systems, adopting adaptive management techniques, and applying scientific approaches to optimize stormwater treatment performance.

Session duration: 45 minutes

About the Presenters

Dr. Chris Hsu is a senior environmental engineer with rigorous compliance experience in storm water and NPDES permitting. He has provided engineering and research support for municipalities and industrial facilities throughout California. He is a licensed Civil Professional Engineer in California and a Qualified Industrial Storm Water Practitioner (QISP) Trainer of Record (ToR).

Blake Van Drimlen is a Staff Engineer with GSI Environmental Inc. His environmental consulting experience primarily includes NPDES permit compliance support, with a focus on storm water engineering and BMP design. He has assisted in the design and implementation of industrial storm water capture and treatment systems, conducted surface water hydrologic modeling, prepared hydraulic design calculations, conducted site inspections and sampling, provided construction/field engineering support for storm water management projects, conducted bench-scale water treatment testing and developed full-scale design recommendations, and has developed O&M procedures and compliance documentation for active water treatment systems.Before joining GSI, Mr. Van Drimlen has accumulated more than 10 years of professional experience in the construction industry. He is a civil drafter proficient in CADD and civil design software, and has produced numerous technical figures, construction plan sets, civil and mechanical design drawings, and analyses.

Natel Hasal joined GSI as an engineering intern in November 2022 while finishing his undergraduate degree in Civil/Environmental Engineering at Cal Poly Pomona. During his internship, he gained experience performing site visits, hydrology modeling, and stormwater treatment design. Mr. Hasal graduated from Cal Poly Pomona in May 2023 and was brought on full-time as an Environmental Engineer to support the stormwater team. Mr. Hasal is proficient in the following software: AutoCAD/Civil3D (Site Plans, Site Topography, Hydrologic Mapping, and Pumping & Instrumentation Diagrams) and Microsoft Excel (Hydrologic Modeling and Data Management).