Remediation and risk management webinar series

Recorded webinars in this series:

Investigative Approach for Petroleum Volatilization to the Indoor Air Pathway (VIAP) Training  (recorded 9/03/24, 89min)
The Investigative Approach for Petroleum VIAP is one of seven volumes that will make up a Guidebook that will eventually update and replace the May 2013 EGLE Guidance Document for the Vapor Intrusion Pathway. The Investigative Approach for Petroleum VIAP is a concise process for the evaluation and screening process at petroleum release sites. Attachments are included to provide more information and details when needed based on site conditions.

Some highlights of this document include:

• Identifies the 3 site conditions where risks from petroleum vapor intrusion have the greatest potential:
•  NAPL entering or being close to a structure.
• Clarifies the use and where to begin the measurement of the lateral inclusion zone – EGLE RRD will be using NAPL and contaminated groundwater; not soil above screening levels absent of NAPL.
• Discusses the use of soil gas data for showing compliance with criteria/screening levels and risk evaluation.
• Outlines the data needs for when a property/structure screens in and needs evaluation.
• Identifies and discusses the need to evaluate conduits when a petroleum vapor source has entered into it.

This new guidance has been released as an electronic resource on RRD’s Vapor Intrusion webpage with the ability to download a hard copy. This webpage was developed to promote a clear and concise way to provide a consistent and informed approach for EGLE for the volatilization to the indoor air pathway using most up to date science.

Overview of Exposure Barriers for the Direct Contact Pathway under Part 201 (recorded 5/29/24, 88min)

The Department of Environment, Great Lakes, and Energy (EGLE), Remediation and Redevelopment Division (RRD) has issued guidance for the minimum requirements of a direct contact exposure barrier after the determination is made that an exposure barrier is necessary under Part 201, Environmental Remediation, to mitigate or prevent exposure through the soil direct contact pathway. Exposure Barriers for the Direct Contact Pathway – Design, Documentation, and Management Guidance Under Part 201 provides guidance on typical design considerations and the minimum requirements when relying on different exposure barrier types, including non-structural (e.g., soil, gravel, or rock) and structural (e.g., building floors, foundations, asphalt, and concrete). It also outlines the documentation, inspection, maintenance, and monitoring requirements when submitting information to the department upon request or for approval. Staff from EGLE-RRD will provide an overview of the use and application of this guidance document.

Increasing Diffusive Mass Flux Rates During In-Situ Groundwater Remediation (recorded 5/07/24, 59min)
Join us for a discussion and explanation of the challenges of remediation of contaminants in clay, saprolite, or glacial till soils. Methods and a case study will be presented to demonstrate how to address these challenges using both chemistry and field implementation methods. Injection with the full understanding of the site geology/hydrogeology provides an opportunity to overcome diffusion limitations existent at low permeability sites with clay dominant lithology or fractured rock. Through injection lense verification techniques, clients have been able to verify the transect of unidentified preferential pathways and connected pockets of residual mass and achieve more rapid remediation results. This eyes-wide-open approach reduces the decades long time scale of remediation to less than a few years.

Human Health Risk and How We Assess It (recorded 3/07/24, 64min)
Risk assessments are an important part of the Michigan Department of Environment, Great Lakes, and Energy’s Remediation and Redevelopment Division’s (RRD) role in implementing the Part 201 and Part 213 environmental contamination response programs and protecting Michigan’s public health and environment. This session will focus mostly on the human health risk assessment process and principles behind developing and applying cleanup criteria. The presenters will be Grace Kuan of RRD’s Toxicology Unit and Erica Bays of RRD’s Compliance and Enforcement Section. 

Petroleum NAPL: Characterization, Remediation, and Management (recorded 11/28/23, 60min)
The Department of Environment, Great Lakes, and Energy, Remediation and Redevelopment Division has updated and reorganized its guidance for the characterization, remediation, and management of petroleum non-aqueous phase liquids (NAPL) in June 2023. This webinar will highlight the changes made to the document, discuss the organization of the document, and discuss the multiple lines of evidence table that has been provided to assist in the organization of the data.

Twenty Years in the Field - Updates to Hawaii’s DU-MIS Guidance (recorded 10/26/23, 61min)
Roger Brewer, with Hawaii’s Department of Health, Hazard Evaluation and Emergency Response Office (HDOH-HEER), will present an overview of the recent updates to Sections 3 and 4 the HDOH-HEER Technical Guidance Manual (TGM). The updates focus on the use of “Decision Unit (DU)” and “Multi Increment® Sample” investigation methods (DU-MIS) for characterizing environmental media. (Multi Increment is a registered trademark of EnviroStat, Inc.). For over 20 years, Hawaii has successfully used the DU-MIS method to investigate sites of environmental contamination. The TGM is a compendium of Hawaii’s knowledge and experience with this method. Updates to the TGM consist of a series of short Fact Sheets, a general overview of the Site Investigation DU-MIS investigation process, and a series of appendices on focused topics. Topics reviewed in the appendices include:

• Conceptual Site Models.
• Theory of Sampling basics.
• DU-MIS Case Studies.
• DU-MIS for surface soils, subsurface soils, sediment, excavations, stockpiles and VOCs.
• Tips on field implementation.
• Laboratory processing and testing.
• Data quality review.
• Use and misuse of existing discrete sampled data; and
• DU-MIS methods under TSCA.

Microplastics: Risk Management, Removal, and Source Reduction (recorded 6/08/23, 57min)
Microplastics have become a global environmental problem due to their abundance, poor biodegradability, toxicological properties, and negative biological effects on aquatic and terrestrial organisms, including humans. Plastic debris enters the aquatic environment via direct dumping or uncontrolled land-based sources and degrades into secondary microplastics, the most abundant type in the environment. Various sources such as tire wear, artificial turf, fertilizers, and land applied biosolids contaminate the terrestrial environment. Removal of microplastics from the environment can be extremely challenging. During this session, the presenter will discuss various sources of microplastics and their fate and transport, human health impacts, source reduction methodologies, and technological challenges.

Speaker: Mala C. Hettiarachchi, PhD, PE
Mala C. Hettiarachchi, PhD, PE is a Senior Engineer at Environmental Resources Group and an Assistant Professor (part-time) at Wayne State University.

Inactive Landfill Initiative: Impact of PFAS & 1,4-Dioxane On Drinking Water Sources (recorded 4/27/23, 56min)
An emerging contaminant investigation in New York State is focused on addressing critical drinking water contamination concerns associated with PFAS compounds and 1,4-dixoane from more than 1,900 inactive landfills. During this session, the presenter will explain a unique ranking system developed to prioritize landfills for site characterization, present data trends in groundwater samples collected at the landfills and in drinking water from downgradient receptors. Additionally, the presenter will discuss challenges overcome during program implementation including agency evolution on PFAS compounds, the scale and concurrent nature of the multifaceted investigation, and management approach to support a statewide emerging contaminant program.

Petroleum Vapor Intrusion – Updates to the Lateral Inclusion Zone Checklist and Vertical Separation Distance Checklist (recorded 2/23/23, 56min)

Petroleum vapor intrusion (PVI) is the process by which hydrocarbons volatilize from petroleum-contaminated soils, groundwater, and light nonaqueous phase liquids and migrate through the vadose zone. EGLE has determined the Interstate Technology & Regulatory Council (ITRC) PVI guidance document provides a suitable process for a petroleum vapor intrusion assessment for the volatilization to indoor air pathway (VIAP) pursuant to relevant statutory provisions. To assist in the use of the site screening process using soil and groundwater data, the department has developed a Precluding Factors Assessment for the ITRC Lateral Inclusion Zone Checklist and a Precluding Factors Assessment for ITRC PVI Separation Distances Checklist. RRD staff will use these checklists when reviewing submittals that propose to rely on the ITRC PVI lateral and/or vertical separation distances. Join EGLE-RRD to hear updates to the PVI checklist and the application at sites with petroleum releases.

Groundwater Modeling for Non-Modelers – Application and Case Studies (recorded 1/19/23, 61min)
Groundwater models are often useful tools in the environmental and hydrogeology fields. Groundwater modeling is a specialized skill, and a December 2021 Remediation and Risk Management Series webinar provided the basics of groundwater modeling for non-modelers. This webinar builds on that foundational understanding to highlight example modeling applications and step through real-life groundwater modeling case studies. This webinar was developed in collaboration with Barr Engineering Co. and the Michigan Department of Environment, Great Lakes, and Energy to provide a look into groundwater modeling applications from both the consulting and regulatory perspectives.