Bjorn Wespestad, PE

Principal Engineer


Contact Information

Phone: (415) 967-6000


Location: Oakland, CA


Vapor Intrusion Assessments and Mitigation Design

Remedial Engineering Design

Environmental Forensics (Source of Timing of Chemical Releases)

Review/Classification of Investigation and Remediation Costs Claim in Environmental Cost Recovery Disputes

Stormwater Modeling


BS, Civil and Environmental Engineering, Rowan University

Bjorn Wespestad, PE

Principal Engineer

Mr. Wespestad is a registered Professional Engineer (PE) with over fifteen years of experience assessing and remediating complex sites, analyzing environmental claims, and providing technical support to major developers, attorneys, insurers, and private landowners. He holds a BS in Civil and Environmental Engineering from Rowan University. Mr. Wespestad specializes in fate and transport analyses, implementing effective remedial and mitigative measures, and stormwater modeling.


Mr. Wespestad has designed and implemented remedial measures for soil, soil vapor, groundwater, and surface water runoff at dozens of sites across the US. In addition, he has designed and overseen the construction of numerous passive and active vapor intrusion mitigation systems in existing and newly constructed buildings across the US. With his experience, he has served as a consulting and testifying expert for complex projects and cases, as well as cost recovery disputes across the country involving metals, chlorinated solvents, petroleum hydrocarbons, and PFAS impacts.

representative projects
  • In Situ Bioremediation Program Design, Multiple Former Dry Cleaning Facilities, Bay Area. Design, oversight, and monitoring of multiple in situ bioremediation programs to remediate chlorinated solvents in the groundwater beneath, and emanating from, multiple former dry cleaner facilities in the Bay Area. In situ bioremediation programs included the injection of a variety of amendments including emulsified vegetable oil, sodium lactate, zero valent iron, natural microbial consortia, and the subsequent implementation of a long-term groundwater performance monitoring program.
  • Active and Passive Vapor Intrusion Mitigation Systems for Multiple Housing Projects, Bay Area, CA. Design, oversight, operation, and monitoring of multiple active vapor intrusion mitigation systems integrated into new residential buildings in the Bay Area. Vapor intrusion mitigation systems included a sub-slab ventilation system, vapor barrier, and infrastructure, including remote monitoring devices to cost-effectively monitor the performance of the mitigation systems.
  • Modeling of Historical Rainfall Events, Sacramento County, CA. Developed a stormwater runoff model to evaluate contributions of pollutants in stormwater runoff from an industrial facility to a surface water body in the Central Valley of California. Modeling work included an evaluation of historical rainfall data, simulation of stormwater runoff from the industrial facility and the surrounding drainage area, and an evaluation of contaminant contributions to the nearby surface water body.
  • Former Dry-Cleaning Facility, Marin County, CA. Technical expert in case involving the source and timing of PCE releases from a former dry cleaning facility in Marin County, California. Mr. Wespestad provided expert testimony regarding the source and timing of PCE at the Site as well as the relative contributions of PCE by various former operators to subsurface impacts beneath the Site.
  • Former Industrial Facility, Los Angeles County, CA. Consulting expert in case involving the classification of investigation, remediation, and mitigation costs associated with chlorinated solvent impacts in soil, soil vapor, and groundwater beneath, and emanating from, a former plating facility in Los Angeles County, California.
  • Catholic Charities vs. Marinwood Plaza. LLC, et al, Marinwood Plaza. LLC vs. Myung K Shin: et. Al. Superior Court of the State of California In and For the County of Marin Case No. CIV 1701875. Trial March 25, 2022 & April 4, 2022. Expert Report.

  • Daniel Souza and Joyce G. Souza, Co-Trustees of The Daniel Souza and Joyce G. Souza Family Trust, under Declaration of Living Trust, dated August 28, 1990 (a Revocable Living Trust); DJA Properties, LLC, v. Mid Valley Services, Inc., a California corporation, dba Mid Valley Financial; Earl Don Baker; Donald Richard Akins; Larry Charles Korth; Trina Louise Root; Garrett Gill; Roy Cordes; Adela Atoigue; and DOES 1-50, inclusive. Superior Court of the State of California, County of Fresno, Case No. 16CECG024l78. Expert Declaration

  • Wespestad, B.; Adams, J.B.; Gerbig, C.; Love, A.H. (2020). Dry Cleaner Releases and Forensic Considerations. Environmental Claims Journal. doi: 10.1080/10406026.2020.1773078