October 25, 2019

Geosyntec Team to Present at the 2019 Southeast Brownfields Conference

David Latham, PG, Eric Sager, P.G. (Florida), Lydia Dorrance, Ph.D. (California), and Helen Dawson, Ph.D. (Washington D.C.), are presenting on multiple topics at the 2019 Southeast Brownfields Conference at the DoubleTree Universal Orlando in Orlando, Florida on October 27-30, 2019.

Cristina Graver, P.E. (Boca Raton) will also be representing Geosyntec at the conference.

David is a Senior Hydrogeologist based in Florida with over 25 years of experience focused on site assessment/remediation, environmental due diligence/compliance, hydrogeologic investigations, litigation support, and geophysical investigations.

Eric is a Principal Geologist based in Florida with over 20 years of experience working collaboratively to build project teams that solve complex problems and meet client expectations. His practice includes site investigations, conceptual site model development, feasibility studies, remedial design and implementation, and long-term monitoring for sites contaminated by volatile organic compounds, petroleum hydrocarbons, polychlorinated biphenyls, pesticides, herbicides, metals, and several emerging contaminants of concern in various media.

Lydia is an Environmental Scientist based in California focused on emerging contaminants, environmental forensics, and litigation support.

Helen is a Senior Principal Civil and Environmental Consultant based in Washington, D.C. with more than 30 years of experience focused on private practice, academia, and public service. Her practice spans a wide range of technical disciplines including vapor intrusion, groundwater characterization, and contaminant fate and transport modeling related to the spread of dense non-aqueous phase liquids, chlorinated solvents, and metals in the environment.

The 2019 Southeast Brownfields Conference is attended by more than 250 attendees from federal, state, local municipalities, consultants, attorneys and others. The agenda splits into three tracks: lessons learned, successes and lifecycle; funding and incentives; and environmental justice.

Geosyntec Contributions

Title: Technical and Regulatory Challenges Resulting from the Historical Use of PFAS at Brownfields Sites
Time: Track B, Session 2B, 1:05 – 2:25 p.m., Monday, October 28
Presenters: Lydia Dorrance, Ph.D., BCEEM, PMP, Eric Sager, P.G., Geosyntec and Lisa Duchene, Esq of The Goldstein Environmental Law Firm.
Abstract: Per- and polyfluoroalkyl substances (PFAS), including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), are a class of man-made chemicals. Due to the strength of their carbonfluorine bonds, PFAS are persistent in the environment and difficult to remediate, and PFAS exposures and risks can result in regulatory concerns and active management at contaminated sites and in surrounding areas. The potential presence of PFAS at brownfield sites has technical, legal, and business risk implications for site redevelopment. There remain many uncertainties associated with characterization, health risks, viability and cost to remediate, future regulations, and potential for reopeners. This presentation will provide an overview of PFAS sources, chemistry, environmental fate and transport, exposure pathways and toxicology. The presenters will discuss the occurrence of PFAS in drinking water sources in the U.S. together with regulatory responses at the federal and state levels. This presentation will focus on providing a synthesis of the state of knowledge regarding the characterization of PFAS-impacted sites with a case study from a large federal facility in Florida detailing lessons learned and best practices. Implications for due diligence regarding potential PFAS presence on brownfield sites will also be addressed. A legal perspective will be provided, including emerging regulations, litigation cases, insurability, and financial disclosure.

Title: Rapid Assessment of Potential Inhalation Risks Due to the Vapor Intrusion Pathway Using Building Pressure Control and High Volume Subslab Testing
Time: Session 4B on 9:00 – 10:20 a.m., Tuesday, October 29
Presenter: Helen Dawson, Ph.D., Geosyntec
Abstract: Vapor intrusion is frequently encountered in redevelopment of brownfield sites. Inhalation risks due to vapor migration of volatile organic compounds (VOCs) from subsurface sources into occupied buildings, referred to as the vapor intrusion (VI) pathway, are challenging to assess using conventional indoor air sampling methods because of temporal and spatial variability in indoor air concentrations and contributions from background sources. Indoor air concentrations measured over periods of a few hours to a day can exhibit greater than 100-fold variability over time and space. Many background sources of VOCs exist in everyday use and vapor emissions from such sources can lead to a high bias in the estimate of VI-related inhalation exposures. This talk describes two innovative test methods for rapidly assessing potential inhalation risks due to the VI pathway: building pressure control (BPC) and high volume subslab sampling (HVS).

BPC provides a means of characterizing building susceptibility to VI and determining background (non-VI) contributions to indoor air VOC concentrations. The test procedure involves depressurizing a building to varying levels, which promotes VI, and subsequently pressurizing it, which hinders VI. Cross-building and cross-slab differential pressure is monitored throughout the test, concurrently with indoor air sampling under the various levels of imposed pressure conditions. Building susceptibility to VI and reasonable maximum exposures due to VI can be determined in a one or two days or less, depending on the size and complexity of the building. The results have been found to exhibit sufficiently low temporal variability (generally less than two-fold) that repeat sampling in different seasons is not needed to support reasonable risk management choices.

HVS provides a means of characterizing the VOC vapor mass loading under the building that could potentially impact indoor air quality through VI and deriving building-specific indoor/subslab attenuation factors. The test procedure involves measuring vapor concentrations as a function of the volume of gas extracted and measuring vacuum under steady and transient periods of vapor extraction from below the building foundation. These data are used to calculate the transmissivity of the subslab materials and the leakance of the slab, parameters that can be used to calculate a building specific attenuation factor. These tests also can be conducted in one or two days or less, depending on the size of the building. Multiple HVS tests at large buildings can be used to distinguish areas of high potential mass loading from areas that don't pose a VI risk and to design an efficient and effective subslab depressurization system to mitigate any VI threat.

Title: SRP Grant Funding as a Project Driver- Two Florida Redevelopment Success Stories
Time: Track B, Session 7B on 3:35 – 4:55 p.m., Tuesday, October 29
Presenters: Presented by David Latham, P.G., Geosyntec, Kristina Nelson, Esq of Finger, Nelson & Maguire, and Lisa Walsh from the City of Ocala Office of Economic Development
Abstract:
The Florida Department of Environmental Protection (FDEP) manages funding provided by the U.S. Environmental Protection Agency (USEPA) for brownfields site cleanups under the State and Tribal Response Program (SRP) Grants. Florida is one of 25 states with a Memorandum of Agreement with the EPA that allows the FDEP to receive this funding towards brownfields cleanups at eligible sites. Accordingly, over the past several years, SRP grant funding has provided valuable contributions to a wide variety of brownfields cleanups across Florida. This presentation will discuss two specific redevelopment projects that benefitted greatly from this grant funding, and it has helped to facilitate redevelopment activities to move forward; the common end goal for these projects is to improve the respective properties to allow for their renewed usage within disadvantaged economic areas of Jacksonville and Ocala.

The Former Byrd & Sons Fuel Oil and LP Gas Site is located in a lower-income, mostly residential neighborhood in Jacksonville, Florida, and it was purchased by a small, local real estate company called Dinestia Holdings (Dinestia). Unfortunately, this company was unaware of historical environmental issues with the property. The site formerly contained above-grade propane gas tanks and an above-grade diesel tank connected to a petroleum dispensing system. There was a historical petroleum discharge associated with a former vehicle fueling dispenser connected to the diesel above-ground storage tank (AST). The law firm of Finger, Nelson & Maguire, PLLC partnered with Geosyntec Consultants (Geosyntec) and FDEP to assist Dinestia through the petroleum cleanup process starting in 2017. The petroleum cleanup was advanced to the successful end point of a Site Rehabilitation Completion Order (SRCO) while allowing the redevelopment work to progress.

The second case study that will be presented involves the Former Royal Oak Enterprises Site in Ocala, Florida. Royal Oak Enterprises reportedly operated as a charcoal manufacturing facility from the 1970s through 2006 on a 24.5-acre property surrounded by low-income residences. Several rounds of site assessment have been conducted at the property including recent soil sampling conducted by Geosyntec under the direction of FDEP utilizing SRP grant funding. Impacts detected in shallow soils include arsenic, barium, and polyaromatic hydrocarbons (PAHs). The City of Ocala purchased the property with proactive plans for redevelopment that will occur in multiple phases. The prior facility buildings have already been demolished. The western portion of the Site has already received an SRCO and will likely be redeveloped first with a large community center. The eastern portion of the site is currently slated for additional soil sampling, soil excavation and the removal of onsite underground storage tanks. This portion of the site currently has a long-term redevelopment plan for mixed use with retail and affordable housing.