LSPA 4th Annual Environmental Symposium

This two-hour session consists of two one-hour presentations along with Question & Answer.  

Presentation 1: Monitored Natural Attenuation (MNA) of Chlorinated Volatile Organic Compounds

This presentation will cover the principles and processes governing the implementation of Monitored Natural Attenuation (MNA), with 

This presentation will be given by Tiffany Duhl, PhD, MassDEP, BWSC NERO, and it will cover the principles and processes governing the implementation of MNA, with an emphasis on MNA at Chlorinated Volatile Organic Compound (CVOC)-contaminated sites. Topics will be presented within the context of the Massachusetts Contingency Plan (MCP) regulatory framework governing MNA implementation and reporting requirements. An overview of attenuative mechanisms applicable to MNA will be provided, with a focus on microbial reductive dechlorination of CVOCs. Prerequisites for establishing that MNA is a viable remedy will be presented, followed by a discussion of site conditions that preclude the use of MNA. Pragmatic recommendations including acceptable ranges of biogeochemical conditions and contaminant-specific parameters will be included, to aid in the determination of whether MNA is likely to be successful at a site. The presentation will also cover lines of evidence to support the use of MNA at CVOCs sites and the goals of performance monitoring to ensure that remedial objectives and regulatory requirements are met. Here is a link to the course outline.

Presentation 2: Designing Effective Monitoring Programs and Practical Lessons Learned from the Field

This presentation will given by Chase Gerbig, PhD, PE, Roux, and Mark Casey, PE, LSP, Terraphase, and it will review how to build effective MCP‑aligned monitoring programs, interpret datasets, apply trend and modeling tools, and use multiple lines of evidence to support MNA. Insights from real‑world NOAFs and NONs will also be shared. Presentation topics include:

• Designing a monitoring program that meets MCP expectations and aligns with site complexity (locations, frequency, parameters—moving beyond just “monitor annually”)
• Spatial and temporal datasets: How much is enough? How long is enough?
• Mass-based vs. concentration-based evaluations: Practical examples illustrating why both matter and when each is preferred.
• Primary, secondary, and tertiary lines of evidence that can support (or refute) MNA determinations
• Predictive and analytical tools: trend analysis and statistical thresholds; modeling/forecasting tools; and use of big data and simple analytics to validate MNA progress 
• NA vs. MNA in practice: lessons from NOAFs, NONs, and transitions

The course will conclude with a question-and-answer session.