In Situ Bio-Remediation of Perc From Syrup to Cheese Whey

Written By Steve Henshaw, P.G., President & CEO of EnviroForensics
As seen in the August 2009 issue of Western Cleaner & Launderer

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For years, environmental scientists and engineers have been promoting the notion of using microorganisms to degrade chlorinated volatile organic compounds (e.g. Perc and associated breakdown products) and petroleum hydrocarbons (e.g. gas, diesel, oil, etc.)  This technology falls under a general term called bio-remediation.  One may recall video of the Valdez oil spill in Alaska, when cleanup crews sprayed microorganisms onto the oil laden shoreline.  The idea was that the microorganisms would literally consume the oil as their food source.  This same phenomenon has been observed in aquifers contaminated with gasoline and oil, whereby the leading edge of the contamination plume is often consumed by naturally occurring microorganisms, while the center of the contamination plume does not have sufficient oxygen for the microorganisms to grow.  The breakdown of petroleum hydrocarbons can be summed up as needing an oxygen rich environment, also known as an aerobic environment, where oxygen is needed to aid in the consumption of the petroleum hydrocarbons.  The result is that gasoline and diesel contaminated plumes are relatively small in length.  As the concentration of gasoline and diesel compounds decrease from the source area, the amount of oxygen increases and the bugs population, in turn, adjusts to the lower concentration food source. Continue reading “In Situ Bio-Remediation of Perc From Syrup to Cheese Whey”

Vapor Intrusion – What is it and How Can it Effect Me?

Written by Steve Henshaw, P.G., President and CEO of EnviroForensics

As seen in the November 2008 issue of Western Cleaner & Launderer

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What is It?

Vapor intrusion is the migration of volatile chemicals, primarily volatile organic chemicals (VOCs) from the subsurface into overlying buildings. Vapor intrusion requires three components: a source, an inhabited building, and a pathway from the source to the inhabitants.

Over the past few years, vapor intrusion has become a significant environmental issue, one that may have a direct impact on your dry cleaning operation.  In fact, just last spring,  the American Society for Testing and Materials (ASTM), the association responsible for creating the procedures and standards for conducting due diligence for banks lending and financing on real property, has suggested that vapor intrusion issues be considered when loaning on real property.   That is to say, is it likely that vapors are coming off of contaminated soil and groundwater that may migrate underneath buildings and enter basements, crawl spaces and confined spaces and rooms.    Figure 1 is an example of a situation where vapors could enter a commercial or residential building. Continue reading “Vapor Intrusion – What is it and How Can it Effect Me?”