Lab 1

Turning Brownfields Green

Introduction

What in the world are "brownfields"? According to the Environmental Protection Agency, brownfields are abandoned, idle or underused industrial and commercial facilities where expansion or redevelopment is complicated by real or perceived environmental contamination. For example, a community may have an oil refinery as one of its major industries. At some point, the refinery may close or be relocated. Now, what does the community do with the refinery site? Of course, they would like to clean up the soil and water so that the land can be used in ways that are fully protective of human health and the environment. According to the brownfields concept, the cleanup must satisfy requirements for its intended use, but it does not require a cleanup that would permit unrestricted use. For instance, the cleanup might enable a brownfields site to be used for golf courses, bikeways, and pathways but not for homes or day care centers.

The process of redeveloping a brownfields site involves many complications. What did the industry leave behind? What are the safe uses that result from the cleanup? Would it be safe to build houses on the site? Would it be safe to build schools on the site? How does a community assess and safely clean up the pollution at such a site? Clearly, there are many aspects of cleaning up a brownfields site. Although such a cleanup involves concerns about air, soil, and water, this lab focuses on groundwater. More than half of us depend on groundwater for our water supply. In many regions, community growth and development depend on this resource. Nevertheless, this precious resource is being threatened by a wide variety of contaminants

Even though this lab is concerned with groundwater, keep in mind that the methods and principles you use could be applied to other aspects of a brownfields cleanup.

Technology Problem

In this laboratory you will investigate groundwater pollution at a site within or near to your local community. You will be asked to develop ways to measure and model groundwater pollution at this site. You may also be asked to investigate methods that could be used to clean up groundwater contamination and evaluate alternative means of remediation. For example, you may use the science of risk assessment to determine alternatives that would allow the property to be placed into safe reuse as quickly as possible.

You will be using the scientific method to solve your problem. The scientific method has five steps: problem, question, hypothesis, test, and decision. The first two steps (problem, question) of the scientific method depend on exploring the situation and developing a better understanding of the problem. At this point, you may want to meet with your instructor to develop a plan for accomplishing this. With the help of your instructor, you might decide to develop a timeline with specific objectives and deadlines. Your exploration will probably begin exploring with some bibliotechnology research.

Bibliotechnology Research

The first step in your bibliotechnology research is to find a site within or near your local community where groundwater pollution is a concern. To find a site go to the EPA brownfields web site: http://www.epa.gov/swerosps/bf/index.html. You will find a listing of brownfields, and you are likely to find a site within or near your local community where groundwater contamination is an issue. Nearly all of the sites listed give local contact information, which includes addresses, phone numbers and e-mail addresses of local officials involved in the analysis and cleanup of brownfields. Usually, members of local government and industry are enthusiastic about helping people in their educational endeavors. Contact your local official and learn about the brownfields in your area. As you work on this technology problem, the local contact will be a valuable resource for data and information essential to the solution of your problem.

You will probably find the need for additional information. Perhaps the first topic that will require exploration will be groundwater. You may need to answer questions like: What is groundwater? How does it get into the ground? How does it behave? What factors control the movement and distribution of groundwater? How does groundwater get polluted? How is polluted groundwater cleaned up? To help answer your questions, there are a number of sources on the Web that discuss groundwater and groundwater pollution. Key words or phrases for accessing pertinent information on the web include groundwater, groundwater pollution, reclamation of groundwater pollution, groundwater contamination, Environmental Protection Agency (EPA), Environmental Council of the States, Environmental Defense Fund. Every state has a department of environmental quality or state environmental protection agency that can provide information about groundwater pollution. In addition, the following web sites will introduce you to groundwater and groundwater pollution issues:

• This site summarizes some basic groundwater concepts and provides links to several groundwater sources.
  http://www.groundwater.com/groundwater_basics.html
• This site leads to information about the earth's water and water quality.
  http://trackstar.hprtec.org/main/display.php3?trackid=402
• This site provides information about the nature, uses, and pollution of groundwater.
  http://www.ec.gc.ca/water/en/nature/grdwtr/e_gdwtr.htm
• This site provides a contextual explanation of groundwater and includes a list of definitions.
  http://www.ianr.unl.edu/pubs/Water/g1128.htm

After investigating a few of these sites, you may discover that you are encountering unfamiliar terminology. It will be helpful to create a glossary of terms. Examples of some terms that you might include in the glossary are: hydrologic gradient, permeability, porosity, aquifer, hydrologic conductivity zones, contaminant migration, non-aqueous phase liquids (dense and light), maximum contaminant levels, etc.

Additional Research

Based on your bibliotechnology research so far, you may have discovered that groundwater behavior can be difficult to understand and model. There does not seem to be one method or technique that would describe groundwater flow at every polluted brownfields site. At this point you may want to meet with your instructor to discuss your progress. Together, you may decide to do some actual experiments with groundwater or work on a mini-project. Your professor should be able to give you some suggestions.

You will eventually need some data. This might be a good time to secure some data on groundwater from your chosen brownfields site. If data is not available on the web, you may need to contact people in your community who may be able to provide this data (often this data is public domain).

Once you have obtained a basic understanding of groundwater in general and have identified a particular brownfields site, you are ready to tackle the technology problem.

Mathematics Tools

In the investigation of this problem, you will need to select mathematics tools that best fit the problem, help explain the problem, and provide a solution to the problem. You may wish to use geologic maps and scale drawings. This will require geometry, proportions, basic algebra, and trigonometry. To describe groundwater flow, you may need the concepts of function or regression to get a predictor equation. You might also try a probabilistic model such as cellular automata.

In the real world it takes a large quantity of data to adequately model groundwater flow. Modern hydrologists and engineers use computer software like MODFLOW or BIOPLUME II to help them analyze this data. Learning more about modeling software may help you better understand the modeling process. Key words for a Web search include groundwater modeling, environmental modeling, USGS, and MODFLOW.

From the very beginning of the laboratory it is important to keep a record of all your sources, as well as the thought processes, arguments, and steps you used to solve the problem. These as well as any physical models and drawings you have constructed, contribute to your model portfolio.

Model Portfolio

As part of the solution to the technology problem, you will need to create a model portfolio. The model portfolio should contain a thorough description of the technology problem and its identifying characteristics. You need to explain the mathematics, technology, and science you use to solve the problem. In addition, you need to include the mathematical and/or physical models you create. It is important that you keep a careful record of all of your work. The model portfolio should be complete enough so that someone else could follow your work step by step. The model portfolio will be very helpful when you present your thesis defense.

Model Development

The third step of the scientific method involves developing a hypothesis about the real world situation under consideration. In this context, you can think of the model(s) that you create as a hypothesis. Your model constitutes a proposal to describe, explain, and solve the technology problem. It will mirror and explain the technology problem as well as reflect its solution.

Your task now is to develop a method to analyze the flow of contaminants in the groundwater. You may wish to develop a conceptual model first. A conceptual model represents your best idea of how the aquifer works. This model should be based on hydrologic parameters as well as geology. You may wish to make a scale drawing and/or model of your site to better understand the geologic and hydrologic conditions pertaining to groundwater. Once you have developed a conceptual model, you need to develop a mathematical model to describe the system. You will need to decide which factors to incorporate into the model and how those factors should be incorporated. Your model may account for things like groundwater flow direction, contaminant migration rates/directions, contaminant concentrations, water levels, chemical solubility, extent of existing contamination, amount of floating product (light NAPL), and specific gravities of various fluids. You will find the need to make assumptions. It is important that you identify and keep track of these assumptions. For example, you might assume that the groundwater behaves uniformly everywhere on the brownfields site. As you develop the model, you should continually ask yourself if your assumptions are reasonable. To start out, you might restrict your model to account for only one or two contaminants present in groundwater or for only a few test wells. Such contaminants are indicator compounds of volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs) and dissolved heavy metals.

We now turn to the fourth and fifth steps of the scientific method – testing the hypothesis and making a decision about the hypothesis.

Test the Model

Now that you have created a model, use it to either predict the conditions in nearby wells at your brownfields site or predict the conditions for time periods that were not used to develop the model, but for which you have data.

Decide to Retain, Reject or Modify the Model

Your action depends on how well your groundwater model actually predicts the flow of the contaminant in question. If it does not predict flow well, you will want to revise the model.

Using the Model

Now that you have a model, you might want to use it to answer some additional questions: Should your brownfields site be cleaned up? What are the consequences of not cleaning up the brownfields site? If the brownfields site needs to be cleaned up, what are some methods that could be implemented to accomplish this? Can the brownfields site be realistically cleaned up in a timely and cost-efficient manner? Can the polluted groundwater be kept from migrating further? Can the polluted groundwater be contained without exposing humans and the environment to it? You may be required to do some additional research on modern methods of groundwater remediation. You might start your web search using the key word "groundwater remediation". Two very interesting methods of remediation that you might research are monitored natural attenuation and bioremediation, including phytoremediation. You may need to consult with your professor for more direction on your specific situation.

Your answers to these questions should include both the scientific information you have gathered on the groundwater at your site as well as additional considerations (economic, political, and health issues). Your conclusion or thesis, together with all supporting materials should be included in the model portfolio.

Thesis Defense

You will be asked to give an oral presentation of your model portfolio. This is called the Thesis Defense. It might help to imagine that you are presenting the results of your research to an audience of decision-makers from the community surrounding your brownfields site. Be sure to include in your defense both a discussion of the groundwater issues at your site and a discussion of your suggested method of remediation.

Key Suggestions:

• Don't procrastinate – develop a reasonable timeline and stick to it.
• You are the primary investigator – your instructor has an advisory role.
• Use your resources – meet with your instructor often.
• Be flexible – remember that models are powerful tools, but do not necessarily provide definitive answers.
• Remember that there is more than one way to model groundwater/contaminant flow.
• Be creative – think of unique ways to solve the problem.