Introduction to Environmental Forensics

3.1 The Difference Between Environmental Forensic Geochemistry and the Standard EPA Methods

Anyone who has been involved in contamination cases is probably acquainted with data generated by standard chemical analyses using methods that have been approved by the United states Environmental Protection Agency (EPA). The information these methods provide is often sufficient to make the distinction necessary in a lawsuit, such as, distinguishing between contamination from dry cleaners (chlorinated solvents), gasoline stations (gasoline and diesel fuel), or plating operations (metals, arsenic and cyanide).

The EPA methods have their limitations, however. They were designed to be quick, quantitative, and inexpensive, and to provide the kind of information that is needed for regulatory decisions. They do not provide detailed information about the exact composition of materials, such as crude oil, gasoline, and other hydrocarbon products, which are really complex mixtures of many different, individual chemicals. Thus, the standard EPA methods often are incapable of distinguishing materials with similar properties, such as gasoline, aviation gas and JP-4, or refined oil and crude oil.

Forensic methods can answer more complicated questions. The forensic chemist has several tools that can be used to distinguish materials with similar properties. These include special sample preparation methods, advanced analytical techniques such as mass spectrometry or stable isotope analysis, and detailed numerical analysis of the output of analytical instruments that reveal the presence, absence, or relative combinations of specific compounds.

Ultimately, the heart of forensic chemistry is the chemists specialized knowledge about the chemicals and mixtures involved. Thus, it is the forensic chemist’s knowledge about issues such as the relative solubility or volatility of different compounds, the different make-up of hydrocarbons from biological or mineral sources and the ability to discern critical patterns in the data that enable the forensic chemist to make the distinctions that the EPA-approved methods were never designed to make.

Expertise is needed for interpretation of environmental forensic results. ZymaX forensic analytical results are delivered as raw data. Highly specialized training in geochemistry and experience in interpreting forensic data is generally necessary to obtain meaningful interpretation of the analytical results. We strongly advise that you take advantage of our consulting services for full benefit of the testing. We will require relevant site-specific information in order to perform the interpretation.

3.2 Introduction to Environmental Forensics

Environmental Forensics, a definition. Environmental Forensic Geochemistry is defined as a scientific methodology developed for identifying petroleum-related and other potentially hazardous environmental contaminants and for determining their sources and time of release. It combines experimental analytical procedures with scientific principles derived from the disciplines of organic geochemistry and hydrogeology. When applied to investigation of escaped petroleum products, Environmental Forensics provide a valuable tool for obtaining scientifically proven, court admissible evidence in environmental legal disputes.

Sources and releases. Release of crude oil and its refined products is the most common source of both catastrophic and chronic pollution problems in the ocean, lakes, rivers, and groundwater. The potential ramifications of such releases, their environmental injury, and the economic losses have resulted in legal battles in suits amounting annually to billions of dollars in casualty and punitive payments.

Broken or leaking pipelines, that cross ocean and land, release crude oil and refined fuels daily. The hundreds of thousands of underground storage tanks in cities throughout the United States and the thousands of giant above-ground storage containers at fuel tank farms and refineries all contribute to a steady and slow release of hydrocarbons into the environment. When soils become saturated with released fuel, the hydrocarbon components can migrate both laterally and vertically and penetrate groundwater. If the hydrocarbons reach drinking water reservoirs, they become a health threat. When fuel smothers vegetation, it can destroy habitats. When crude oil is discarded with bilge from ships along coastlines, it forms tar, which coats the sand of beaches. When property is damaged or destroyed, the responsible party is sought.

Finding a responsible party. Although there may be strong evidence to indict a particular party, the effects of an accidental release may be far-reaching, because the pollutants can migrate over large distances and affect areas far removed from the location of immediate impact. Under such circumstances, there is a strong possibility that different hydrocarbon product plumes from different sources will mix. When this occurs, complex mixtures of fuels result, some of which may undergo extensive alteration, changing their original chemical composition. To identify the fuel types in those mixtures becomes a challenge.

Preparing a legal claim.Two additional pieces of information are often necessary in preparing a legal claim:

  1. an accurate estimate of the mixing ratio, which will allow an allocation of responsibility.
  2. more difficult to determine, is the date of release of the hydrocarbon fuels to the environment. Reimbursement by a particular insurance carrier could depend on the timing of the release and whether a valid policy covered the incident at the estimated time.

The need for potentially responsible parties and their insurance carriers to determine liability for releasing the chemicals, and consequently, for the cleanup of petroleum contaminants has resulted in increasingly sophisticated analytical and interpretative approaches to identify sources of contamination.

Analytical methods. At ZymaX we use a suite of analytical methods for characterization of petroleum products, in order to analyze environmental samples from sites, where the character and source of contamination by petroleum-derived material are not obvious:

  • EPA Methods, i.e. standard methods developed by the USEPA (United States Environmental Protection Agency)
  • ASTM Methods, developed by ASTM (American Society for Testing and Materials)
  • Conventional and modified geochemical methods for characterization of petroleum products

The use of this battery of Environmental Forensics tests (described later under 5.2 Analytical Procedures and in the list of Analyses Sorted by Application performed by ZymaX forensics) and their interpretation, using years of experience in geochemistry, makes it possible to:

1. identify the types of product which have been released
2. distinguish between similar products from different sources
3. estimate the mixing ratios of different products
4. estimate the age of the product
5. assign probable responsibility for source(s) of the contamination
6. give expert witness testimony and represent either plaintiffs or defendants in litigation
7. and determine the contamination source and its history in many cases (Kaplan, 1992).

Next: The Origin and Chemistry of Petroleum

Interested in Environmental Services?

We'd love to tell you more!

Contact Us Today