Category: Environmental

Zero-Valent Iron Shows Promise As a Strong Chemical Reducer of Perc

Posted on by Jeff Carnahan

Written by Steve Henshaw, P.G., President & CEO, EnviroForensics, in Collaboration with Keith Gaskill, L.P.G., Project Manager and Geochemist, EnviroForensics
As seen in the May 2011 issue of Cleaner & Launderer

PDF Version

Zero-valent iron (ZVI) has been used in the groundwater remediation industry for several decades.  Typically, granular scale ZVI was emplaced in trenches serving as a permeable reactive barrier wall, whereby contaminated groundwater would flow through the wall and volatile organic compounds (VOCs) like Perc would react with the material and breakdown.

This technology worked so well that scientists started applying the ZVI into contamination source areas and hot spots.  Recent advances have produced smaller scale iron particles that can be mixed into a slurry and pumped into the ground through the use of pre-existing injection technologies.  Continue reading “Zero-Valent Iron Shows Promise As a Strong Chemical Reducer of Perc”

Vapor Intrusion; Who’s DEFAULT is it?

Posted on by Jeff Carnahan

Written by Steve Henshaw, P.G., President & CEO, EnviroForensics, in Collaboration with Jeff Carnahan, L.P.G., Senior Project Manager, EnviroForensics.

As seen in the March 2011 issue of Cleaner & Launderer.

PDF Version

As most drycleaners know, at some time in the not too distant future, you or someone you know will have to deal with the accidental release of perchloroethylene (Perc) or Stoddard solvent.  Even if the release is decades old and unknown to the current owner/operator, soil and/or groundwater contamination may come to light during a property transaction, a refinance or through the course of standard due diligence investigations.  This finding commonly results in a demand by the state environmental regulatory agency to determine the extent of the contamination and if necessary, remediate the contamination. 

Environmental regulatory agencies often prioritize contaminated sites based on whether or not people may come into contact with, or be exposed to toxic chemicals.  The three primary ways (or pathways) that people can come into contact with these chemicals is by getting contaminated soil or groundwater on their skin, eating and ingesting contaminated soil or groundwater, or by inhaling the chemicals that volatilize from the contaminated soil or groundwater.  If it is determined that one of these potential exposure pathways is complete, it becomes a priority to abate the exposure immediately, even before the extent of the impacts have been fully defined.  Continue reading “Vapor Intrusion; Who’s DEFAULT is it?”

Ladies, Keep Your Eye On Your Mister

Posted on by Jeff Carnahan

And Other Separator Water Issues

Written by Steve Henshaw, P.G., President & CEO, EnviroForensics
As seen in the November 2010 issue of Cleaner & Launderer

Cleaning and purifying dry cleaning solvents for reuse has been around since the beginning of the dry cleaning industry.  Historically, solvents were considered inexpensive, so the degree to which they were reclaimed was considerably less than it is today.  The rule of thumb used to be a 1 to 5 loss/recovery ratio.  That means that 1 part solvent was lost for every 5 parts recycled.  Today that ratio is much, much lower with some dry cleaners telling me they lose only 1 part of perchlorotheylene (perc) for every 20 parts recycled. 

While the dry cleaning machines, now in what’s considered their 5th and 6th generation, are much better designed and considered safer for the environment, the management of separator water continues to pose environmental concerns.  Separator water is generated during the distillation and solvent recovery process.  Vapors from the distillation process are condensed into a mixture of solvent and water.  The solvent is typically recoverd from the mixture by gravity in the water separator.  The remaining water in the separator has dissolved solvents in it and if the solvent being used is perc, the separator water will more likely than not be considered a hazardous waste. Continue reading “Ladies, Keep Your Eye On Your Mister”

What Drives an Environmental Cleanup?

Posted on by Jeff Carnahan

Written by Stephen Henshaw, P.G., President and CEO, EnviroForensics
As seen in the August 2010 issue of Cleaner & Launderer

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I frequently get calls from dry cleaners asking for advice and one of the common questions is, “How much is it going to cost to cleanup my site?” Knowing that my dry cleaner friend is looking for an answer better than “depends” and realizing that it is impossible to give him an accurate cost without knowing a lot more about the site conditions, I find myself walking a bit of a tightrope. Environmental cleanups are driven by several factors, but the primary factor is risk. The risk is whether the chemical release could impact the environmental that supports animal life, as an example, wetlands, creeks, streams, lakes and oceans.

Of course, in stating these primary risk factors, one cannot ignore property damage immediately below the cleaners or at the adjacent properties where contamination has migrated. And last but not least, a regulatory agency can bring a third party claim against a dry cleaner to cleanup contamination to the lowest of levels, but in general the primary factors presented apply.

So, how can one determine whether or not a threat exists or is present to human health and/or the environment? We have to determine if the release has reached either people or the environment. Continue reading “What Drives an Environmental Cleanup?”

State Level Environmental Enforcement During Periods of Economic Downturn

Posted on by Jeff Carnahan

Written By Stephen Henshaw, P.G., President and CEO, EnviroForensics
As seen in the July 2010 issue of Cleaner & Launderer.

PDF Version

The current state of the economy affects so many areas of our lives, but one that isn’t talked about much is how the current hiring freezes imposed by almost every state environmental agency impacts environmental cleanups.  It is safe to say that the state-level regulatory agencies are not hiring new staff to handle environmental cleanups.  While this may initially sound like a good thing in that dry cleaners may feel they have some breathing room from the long arm of the law, I see it a differently.   

In general, the environmental regulations continue to get tougher and the acceptable levels of chemical constituents allowed to remain in soil, vapor and groundwater continue to be lowered.  Because many sites take a long period of time before they are cleaned up to acceptable levels and “closed”, the project managers working for local, state, and federal regulatory agencies continue to get more and more sites that they are responsible for managing.  Their workload continues to increase in volume and the piles of reports and work plans they are to review keep growing. Continue reading “State Level Environmental Enforcement During Periods of Economic Downturn”