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Environmental Investigation and Remediation of a Hazardous Waste Site

Part 2 - Analysis of Existing Information and Regulatory Concerns

Samir G. Khoury, Ph.D., P.G.


Course Outline

This course, Part 2: Analysis of Existing Information and Regulatory Concerns, follows the systematic examination of existing information about the disposal activities that took place at the site and the interpretation of archived environmental testing results. The purpose was to understand what information was already available and what interpretations could be made in order to plan the next phase of work. The specific items addressed include:

The course identifies when assumptions had to be made where data were incomplete, missing, or of suspect quality. The analytical results of early groundwater, surface water and soil testing are summarized and the value of this information in planning additional field sampling and testing is discussed. This case history explains the difficulties encountered in attempting to interpret existing conditions using this often incomplete or questionable data set.

Once compiled, the existing information was presented to the Institute and appropriate state regulatory agencies. Their comments and the Institute’s responses are presented in this course.  A newspaper article announcing that environmental contamination was detected at the site is also presented.

A glossary of terms and acronyms used in this series of courses follows the summary section at the end of this course.

This course includes a multiple choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the end of this course, the student should understand the importance of conducting a thorough compilation, evaluation and analysis of existing environmental information prior to designing new field investigation programs. Using information about the waste disposal site, the student should learn how to:

The student will see the value of using existing information to develop consensus among the interested parties: the Institute, Consultant, and Regulatory Agencies, in order to scope the new work to be performed at the site. The student will also be exposed to the pressure that is brought to bear on the parties by the publication and airing of articles about this subject in the news media.

Intended Audience

This series of courses is intended for environmental engineers, environmental scientists, geotechnical engineers, civil engineers, engineering geologists, environmental geologists, hydrologists and other individuals who are interested to learn how environmental investigations are conducted.

Benefit to Attendees

Students who take this series of courses will learn how environmental problems are investigated; feasibility studies conducted and engineered remediation implemented. These steps are taken to prevent the spread and migration of contaminants to the accessible environment, thus protecting the health and safety of the population and stopping the otherwise inevitable and continual degradation of the environment.

Course Introduction

For many years a Research Institute (Institute) carried out experiments using both radioactive materials and organic and inorganic chemicals in its laboratories. In order to dispose of the waste products of this research the Institute operated a shallow land burial facility for twenty years on the grounds of its research campus. The shallow land burial was accomplished by randomly placing both liquid and solid wastes, held in various types of containers, into narrow parallel trenches dug into the soil to a maximum depth of about 8 to 12 feet below the ground surface. Once a trench was filled to within 4 feet below the surface, dirt was placed over the waste, graded, fertilized and seeded. In areas where parts of older trenches subsided, due to breakage of containers or compaction of the waste, additional dirt was placed in the sunken areas and these parts were re-graded and re-seeded. The site itself slopes gently downhill, so that surface water would run off the burial area and into the woods downslope of the landfill. The site is located in a part of the U.S. that receives about 35 to 45 inches of rainfall a year.

Once the site was no longer used, it was fenced, posted and locked. Minimal grounds maintenance was done until the State Radiation Protection Agency (State RPA) notified the Institute that they were to keep the fence clear of vegetation and the area within and just outside the fence mowed and free of trees. The following photo shows the waste disposal area after the site was decommissioned and grounds maintenance started:

Figure 1

Figure 1: Decommissioned waste disposal site at the Institute

Importantly, shallow land burial of chemical and radioactive wastes at this site was conducted in accordance with the accepted state and federal standards during the time of operation. The Institute was never cited for improper disposal practices or other violations. Both the Institute and the regulatory agencies agreed that the site was managed and operated properly.

Since the late 1980’s, however, public awareness of the dangers of contamination from landfills of all types was growing throughout the country. In response to this heightened awareness, regulatory agencies charged with the protection of public health and safety became increasingly concerned that disposal practices that were once considered acceptable may have long-term negative impacts on the groundwater, surface water and soil. The Environmental Protection Agency issued drinking water standards that specified minimum acceptable levels for a number of common industrial chemicals, including some radioisotopes. Federal and state legislation required environmental agencies throughout the U.S. to investigate operating, decommissioned and abandoned landfills of all types. The Superfund program was also initiated at the federal level to help fund cleanup of hazardous waste landfills.

Following the decommissioning of the waste disposal site by the Institute, the State RPA initiated a program of soil, vegetation and surface water sampling. Yearly testing showed no evidence of significant radioactive contamination outside the burial area. Several years later, the State RPA recommended that the Institute install a series of monitoring wells to allow sampling and testing of the groundwater. In response, the Institute, under the guidance of the State Groundwater Protection Agency (State GPA), installed five monitoring wells around the waste disposal site, as shown on the following figure.

Figure 2

Figure 2: Location of initial monitoring wells surrounding the waste disposal site

About a month after installation, the State RPA collected groundwater samples from the five monitoring wells for radiological analysis. About a year later, one additional groundwater sample was collected from Well #3 for radiological and organic chemical analysis. The radiological analyses indicated that some of the groundwater samples in the immediate surroundings, south of the fenced area, had elevated Tritium activities. It also appeared that organic chemical contamination might be present in the groundwater in the vicinity of the disposal area. Discovery of both chemical and radiological contamination outside the fenced-in burial area prompted the State RPA to require the Institute to design and implement an extensive investigation program. The Institute issued a Request for Proposals (RFP) to environmental and engineering firms to retain the services of a qualified technical services consultant (Consultant). Part 1 of this series of courses, entitled: Background and History Leading to Contract Award summarized the actions that led to a signed contract between the Institute and the Consultant and reported on the initial meetings with the various regulatory agencies.

As part of the scope of work, the Consultant had proposed to first review existing information, develop an estimate of the inventory of the waste disposed of at the site, and evaluate existing soil, vegetation, groundwater and surface water test results. At the end of this phase of the work, the Consultant would then issue a Preliminary Site Condition Report summarizing the results of these initial studies. The results of this scope work, comments of the state agencies, and responses to those comments are presented in this course. At this point, the media also became interested in this project. The text of one of the news articles is included at the end of this course to illustrate the type of coverage that often accompanies work initiation on such hazardous waste projects.

A glossary of terms and acronyms used in this series of courses follows the summary section, at the end of this course.

Course Content

The course content is in the following PDF file:

Environmental Investigation and Remediation of a Hazardous Waste Site: Part 2 - Analysis of Existing Information and Regulatory Concerns

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Course Summary

This course addressed the collection and analysis of available data about the waste disposal site. The information was reviewed and interpreted in order to share the results with the client and the appropriate regulatory agencies. This was done in order to bring all concerned parties to a common level of understanding and generate a general consensus about the thrust of the initial phase of new field work.

After disposal ceased, the State Radiation Protection Agency continued to inspect the disposal site periodically, and conducted an annual survey of existing conditions. The results of these inspections are presented and include: sample types, locations and analytical results. As a follow-up, and at the request of the regulatory agencies, five monitoring wells were installed around the waste disposal site. Groundwater samples from these wells were collected and analyzed. The results of these analyses indicated that, although there is clearly some radioactive contamination from the waste, concentrations are low and well below the safe drinking water limits in place at that time. The State RPA was more concerned about the identified chemical contamination, especially in those compounds which did exceed the state regulated concentration standards.

The Preliminary Site Condition Report was submitted to the Institute by the Consultant at the end of the compilation and analysis of existing information. The Institute forwarded copies to the State RPA, the State GPA and the State WMA. Their written comments and the Consultant’s written responses were presented and the ensuing Press coverage of this report was also included.

This course emphasized the importance of conducting a thorough review and analysis of existing information before implementing new work. Critically evaluating this information for reasonableness is an important step in the planning of follow-up work.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.