Forensics come to environmental claims: forensic tools used in the medical field are now being applied to solve environmental problems and to investigate claims. (Environmental).

The popular television series "Quincy M.E." first brought to the public's attention the role of forensics in the medical field. The highly publicized O.J. Simpson trial in 1995 also demonstrated the use of forensic tools. More recently, the Discovery Channel launched "The New Detectives," a series of recreations of real criminal investigations and the forensic applications used to solve cases. One of today's most popular TV programs is "CSI: Crime Scene Investigators," which also focuses on the use of forensic sciences to solve crimes.

While medical forensics is a well-known and highly dramatized investigative discipline, the field of environmental forensics is relatively new. The results can be very dramatic for companies faced with environmental litigation or claims. Environmental forensics is essentially the use of science and technology applied to solve environmental problems and litigation. The tools and applications used are much different than those used in medical and criminal investigations. In the handling of environmental claims, however, these forensic applications can be useful, especially in:

* Identifying the source of pollution;

* Determining when the release of a pollutant into the environment occurred;

* Segregating and identifying multiple contaminant plumes;

* Allocating investigation and remedial costs;

* Recovering remediation costs from responsible parties;

* Defending third-party lawsuits of environmental trespass;

* Defending toxic tort claims.

The environment is similar to medicine in that there are numerous systems operating independently of one another, which coexist in various media (i.e., soils, groundwater, air, and surface water). The environment is a complex system and understanding the mechanisms that drive how pollutants behave is even more complicated. Likewise, the behavior of a pollutant is also dependent on its physical and chemical characteristics. Environmental professionals have dedicated entire careers to researching and understanding how groundwater flows or how a pollutant behaves once introduced into the subsurface.

Understanding how pollutants will behave in the environment requires a multidisciplinary approach. Rarely does one have all the information available on a site, as this would be cost prohibitive. Therefore, there is a need for good science and engineering judgment. Methods for site characterization and remediation are well known. In the case of cost allocation or cost recovery litigation, there are benefits to using environmental forensic methods performed by a qualified expert.

Chemical Fingerprinting

Similar to identifying people by their unique fingerprints, chemicals present in the subsurface (i.e., pollutants) have unique characteristics that can be used for identification purposes. Chemical fingerprinting, which is most commonly used in petroleum-related cases, in its simplest form can be used to differentiate between various types of petroleum products such as gasoline, diesel fuel, kerosene, heating oils, jet fuel, etc. Fingerprinting can also be used to distinguish between two similar products. For example, an Exxon gasoline has certain markers and additives, whereas a Shell gasoline is refined a little differently and has its own unique markers and additives. With proper sample selection, preparation, analytical testing, and interpretation of the results by a qualified professional, the two gasoline products can be distinguished from one another.

Chemical fingerprinting can be a valuable forensic tool in determining coverage under an environmental insurance policy, for instance in allocating the costs of cleanup that are covered under the subject policy or pursuing a responsible party for contribution of its share of the cleanup costs.

Aerial Photography 

The review and interpretation of aerial photographs is a technique that can establish historical information and practices of a particular site. For example, the presence of above-ground storage tanks or waste lagoons can be identified easily on an aerial photograph. In addition, aerial photographs can be used to identify ditches, drum storage areas, waste piles, stressed vegetation, and stains on the ground surface.

Because these photographs are typically dated, they serve as helpful tools in assigning responsibilities based on the ownership and operational history of the subject facility. Aerial photographs can also be used for identifying areas for investigation to age date or identify the potential sources of contamination. In conjunction with depositions of former employees, aerial photographs are a powerful tool for piecing together the waste-handling practices at a given site.

Environmental insurance policies sometimes contain retroactive dates of coverage. Upon discovery of historical pollution at a site, the question then arises of when the polluting event occurred in order to determine coverage under the policy. The use of aerial photography can be very useful in making that determination.

But one of the challenges is identifying and obtaining photographs covering the site and the time period in question. There are numerous sources of aerial photographs that the insurance company can research. The primary source is the United States Geologic Survey (USGS) Aerial Photographic Library, a collection of nearly 300,000 photographs taken during geologic studies of the United States and its territories from 1869 to the present. More information on the USGS and its library of aerial photographs can be found on the Web at http:// ask.usgs.gov/photos.html.

Other potential public sources of aerial photographs include the U.S. Department of Agriculture, the National Oceanic and Atmospheric Administration, U.S. Army Corp of Engineers, American Soil Conservation Services, county tax offices, and local departments of transportation. There are also private firms that can provide a wide selection of photographs. Finally, the subject facility may have historical aerial photographs in their archives.

UST Corrosion Models

When oil was discovered in Titusville, Pa., in 1859, wooden barrels were used to store this "black gold." Their storage capacity was limited, however. In the late 1800s, riveted steel tanks replaced the wooden barrel. In the 1920s and 1930s, the riveted steel tanks gave way to welded steel tanks. Both riveted and welded steel tanks were buried underground. Many of these tanks ultimately leaked.

Leaking underground storage tanks (USTs) historically have been a primary source of contamination of subsurface soils and groundwater. Tank corrosion is the primary cause of these leaks. Since those early days, UST technology has evolved considerably and technological innovations were developed to reduce leaks. The life of a steel UST is unpredictable; it depends on the thickness of the steel, installation practices, and various soil characteristics.

The American Petroleum Institute developed a statistical method known as the Mean Time to Corrosion Failure (MTCF), which can be used to estimate the mean time to failure of an unprotected carbon steel UST as a result of corrosion. The method uses tank specifics and soil characteristic data to estimate when a UST began leaking. This data along with tank installation dates can be input into the model to approximate when the tank began leaking.

When analyzing coverage under an environmental policy with a retroactive date, this technique can be useful in determining when the tank failed and began polluting the subsurface, and ultimately determining coverage under the policy.

Chemical Use

Knowledge of the historical use of chemicals and the appropriate application of this knowledge can also be considered environmental forensics in its own right. The most common pollutant found in the environment is gasoline. As previously mentioned, USTs have been a primary source of subsurface soil and groundwater contamination. The formulation and additives of gasoline have changed over time and knowledge of this can be a powerful tool.

Some additives of gasoline include tetaethyl lead (1923), tetramethyl lead (1960), and methyl tert-butyl ether (MTBE) introduced in the late 1970s and early 1980s. Just as important as knowing when additives were introduced is knowing when a particular additive was phased out.

As a result of the documented health effects of lead emissions from gasoline into the atmosphere from automobile exhausts, lead was required to be removed from gasoline. In 1973, the United States Environmental Protection Agency (EPA) initiated incremental reductions of lead in gasoline over a 10-year period. Then in 1990, the EPA passed the Clean Air Act Amendments, which required the complete phase out of lead from gasoline by December 31, 1995. This phase out, however, only applied to over-the-road vehicles. Leaded gasoline is still used in aviation, farm machinery and racing, and must be taken into consideration during a site evaluation.

With this type of knowledge and appropriate site testing data, a qualified professional can approximate the time period of when a pollution event occurred. This information can be critical in identifying or eliminating responsible parties. For example, if MTBE was discovered as a pollutant in the groundwater, the source of that MTBE contamination would be from an. occurrence subsequent to the late 1970s.

This technique is not limited to gasoline only. It can be applied to other sources of pollution as well and is especially applicable to dating pesticides and herbicides. The first large-scale application of the pesticide DDT occurred in 1943; however, it was subsequently banned from use on January 1, 1973. Knowing this information would obviously provide a time period when the DDT was applied.

Transport Modeling

Once the origin of a pollution condition is known, other techniques may help determine when the pollution event occurred. This is especially useful in environmental claims to determine which insurance policy, if any, will provide coverage and pay for remediation. Various models and calculations can be used to estimate when the pollution occurrence first began. By knowing the distance, physical characteristics of the various media (i.e. surface, soils, and groundwater), as well as the characteristics of the contaminant, these models and calculations can provide estimates of how long it took for the pollution to travel a certain distance. This can be quite complicated, as you must consider the various media through which the contaminant has traveled. For example, if a spill of a chemical occurred on a concrete surface and was discovered 500 feet down gradient in the groundwater, you have to consider three media.

The travel time through the asphalt and soils until the chemical reached the groundwater must be estimated. Then a third estimate of the migration time within the groundwater must be calculated. Adding the three travel times will provide an estimate of when the pollution event occurred.

Retain An Expert

In addition to the five preceding techniques, other environmental forensic tools are also available and include, but are not limited to:

* Chemical and biological degradation models

* Radioactive isotope dating

* Tank inventory reconciliation

The use of two or more forensic techniques can be used independent of each other or in conjunction, but, more importantly, you need to retain the right expert to perform these techniques. The cost of employing environmental forensic techniques may vary greatly depending on the complexity of the situation. But, thorough research is essential to ensure that the results are defensible and, ultimately, the data or information generated from these techniques can be money well spent.

Marlin Zechman is an assistant vice president at XL Environmental Inc. XL Environmental Inc. is part of XL Insurance, which is comprised of the insurance operations of XL Capital Ltd. XL Insurance meets the business risk management needs of its worldwide customers through distinctive expertise in a wide range of industries. Visit its Web site at www.xlenvironmental.com.