As a continuation of our Vapor Intrusion Investigation (VII) series, it is extremely beneficial for environmental practitioners to (at the very least) have an understanding of what some of the more pervasive industrial chemicals are, “why” they are significant, and what happens when they show up during a VII. For this, post we’ll take a quick look Tetrachloroethylene (“PCE” or “PERC”)…which frequently shows up at industrial, commercial, and sometimes residential investigations.

CAS Registry Number: 127-18-4
Common Uses: Dry-cleaning, metal degreasing, textile manufacturing, automotive cleaners, etc.
Common Causes of Spills / Discharges: Improper handling & disposal, leaking storage tanks, etc.
Exposure Routes in Humans: Inhalation, direct contact (through the skin), ingestion (contaminated food & water).
Health Affects[1]: Dizziness, nausea, difficult walking & speaking, unconsciousness, and death.
Remediation Options: Excavation, Soil Vapor Extraction (SVE), In-Situ Chemical Oxidation, Thermal, Biodegradation, Natural Attenuation.

As we have indicated in the past, there is plenty of research, data, and guidance on many of the topics we discuss; however, the State Coalition for Remediation of Drycleaners (SCRD) prepared “A Citizen’s Guide to Drycleaner Cleanup” which is a great resource.

When evaluating PCE and VI, it’s critical to understand the potential fears associated with the PCE contamination (e.g. reduced property value, health effects, remediation costs, etc.). As a result, a VII should be overseen and/or conducted by experienced environmental professionals that not only understand how to interpret data, but also know how to collect “representative” data. More importantly, understanding “how” the media (soil, groundwater, air) became impacted and “where” to look is vital to the success of a VII, and will often challenge even the most experienced professional. Common areas to evaluate include interior trenches and sump pits, USTs, storage areas, floor drains, and background sources, but don’t forget the less common and less visible areas (e.g. off-gassing from contaminated concrete, old / decaying subgrade piping, former process vents, etc.).

We hope that you find these posts informative, and relatively useful, and your feedback is always welcome. For further information regarding the Vapor Intrusion Investigation process, please don't hesitate to contact us. tfrancis@cardinallsrp.com, www.cardinalLSRP.com.

[1] Agency for Toxic Substances and Disease Registry

Div. of Toxicology and Human Health Sciences

Tetrachloroethylene – ToxFAQstm

September 1997