February 2021

Collecting Groundwater Samples for PFAS Analysis using Dedicated Teflon® Lined Tubing and Bladders

Sounds crazy, right? Look at any PFAS sampling guidance and the items topping the list of banned sampling equipment are polytetrafluoroethylene (PTFE) lined tubing and pump bladders. PTFE is a strong, tough, waxy synthetic resin, known by such trademarks as Teflon®, Fluon, Hostaflon, and Polyflon. PTFE materials are known for their high temperature, resistance, their chemical resistance

to solvents, acids and bases, properties which make them the perfect material for environmental sampling equipment. That was until per- and polyfluoralkyl substances (PFAS) emerged on the scene. The problem with using sampling materials containing PTFE for the collection of PFAS groundwater samples is that PFAS compounds are process agents used in making PTFE, and thus the use of PTFE sampling materials to collect PFAS samples creates a potential cross-contamination concern.  So, who in their right mind would use PTFE lined sampling equipment to collect samples for PFAS? Well, call us crazy, but we did and what we found out might surprise you.

Cox-Colvin & Associates, Inc., is proud to be a founding member of AVIP. The organization’s purpose is to establish a community of Vapor Intrusion professionals who are dedicated to advancing the industry, exploring new technologies and sharing knowledge and science related to Vapor Intrusion (VI). AVIP will also be a central resource for technology, guidance, standards, credentialing and best practices.

We look forward to working with you to increase the standard of practice in the VI Industry!


EPA Releases Interim Guidance on the Destruction and Disposal of PFAS Substances and Materials Containing PFAS 

PFAS analysis of waste and environmental media is now common place, and it seems that with every sample, more PFAS containing waste is identified. Given the unusual characteristics of PFAS substances, how should the PFAS containing waste and PFAS containing environmental media be disposed? Environmental managers are being forced to answer this question with greater frequency than ever before. In December 2020, U.S. EPA (EPA) released its anxiously awaited guidance on the destruction and disposal of PFAS substances and material containing PFAS.

Widely Used EPA Regional Screening Levels Updated in November 2020

EPA recently updated its widely used Regional Screening Levels (RSLs). The updated RSLs (dated November 2020) replace the May 2020 version. The November 2020 update includes RSL changes for approximately 10 compounds including new indoor air RSLs for trans-1,2-dichloroethylene, molybdenum, vinyl bromide, and 4-chlorobenzotriflouride. To find out how to stay apprised of updates to the RSLs, read more …  

Horizontal Drilling: A Valuable Tool in the Right Situation

Horizontal or directional drilling technology was originally developed by the oil industry and is also commonly used for utility installation and river crossings. Since the early 1990’s, horizontal drilling technologies have been demonstrated and deployed as an enhanced access method for the for use in the remediation of contaminated soil and groundwater.  Yet despite the success and potential benefits of this technology, it remains relatively underutilized in the environmental field.

Cox-Colvin & Associates, Inc.

Project Spotlight

Coming Soon

  • Ohio EPA Completes Testing Drinking Water Under Ohio PFAS Action Plan
  • More on indicators, tracers, and surrogates in vapor intrusion assessments

Upcoming Events

March 9-10, 2021 (Central European Time)  UK Brownfield Summit – GROUND GAS – Laurie Chilcote will be presenting during the Ground Gas Session “Innovative and Proven Methods to Refine your Vapor Intrusion Conceptual Site Model”

March 23-24, 2021 (Central European Time)  UK Brownfield Summit – GROUNDWATER – Craig Cox will be presenting – “Same VOCs, Very Different Outcomes – Lessons Learned from Two Groundwater Remediation Sites”

March 22-25, 2021 (PST) – AEHS West Coast – 30th Annual International Conference on Soil, Water, Energy, and Air – Vapor Pin Enterprises, Inc., will have a virtual booth.

March 23, 2021 (PST) in Session 10: Innovative Remedial Technologies Session- AEHS West Coast – 30th Annual International Conference on Soil, Water, Energy, and Air – Craig Cox will be presenting “Data Visualization Techniques used to Evaluate a Large Co-Mingled Plume in Western Ohio”

April 9, 2021 9am – 1 pm (EST) – Successful Air & Vapor Data Collection: Best Practices Craig Cox and Laurie Chilcote, Cox-Colvin & Associates, Inc. will be presenting – Vapor Probe Selection, Sub-slab Sampling Applications, Pre-sampling and Field Integrity Checks