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Phytoremediation: A New Avenue For Landscape Architecture
Pamela Brown, Student ASLA

California State Polytechnic University, Pomona
Advisors: Joan M. Safford, ASLA


Problem Researched- My research focused on the use of phytoremediation to help mitigate the degradation of our soils and water bodies by contaminants (organic and inorganic) caused by human acts. I begin with a brief synopsis of past human behaviors and how the lifestyles of people in an industrialized civilization led to the contamination problem societies face today. It was important to begin with this in order to establish some of the many factors that created a “need” for alternative remediation techniques and to put the topic of phytoremediation into the context of sustainability and land stewardship as it relates to landscape architects.

Relationships Investigated- Definitions of phytoremediation as a general term are given as well as a breakdown of the different remediation mechanisms in plants. The six remediation mechanisms are explained to clearly differentiate how plants remediate contaminants, what parts of the plants are used, and what can happen to the contaminants once they are removed from the soil or water. I then take a look at the benefits and limitations of each of these mechanisms and how they relate to the ecological, aesthetic, and economic values of any given site. I also discuss some of the scientific concerns of phytoremediation as a new technology and how it might affect matters ranging from the food chain to societal viewpoints.

Disposal of remediated contaminants is equally important as removing them from the soils and water bodies in the first place. The Environmental Protection Agency has created laws that govern the disposal of hazardous waste and in doing so, has helped to create the need for new treatment methods for this waste and requirements reducing the amount biomass disposed. I review some of these current methods of treatment and what types of contaminants are treated with these methods as well as new processes that may be utilized in the near future.

As with many projects, cost is a concern to all parties involved and can be a determining factor as to whether or not phytoremediation techniques will be feasible for any given site requiring remediation. I list a breakdown of probable costs that the Naval Facilities Engineering Service Center, Port Hueneme uses to estimate costs of their phytoremediation projects. I then compare the costs of conventional remediation techniques with phytoremediation techniques of the same contaminant to demonstrate the potential economic savings of the latter technique. Further detail of one of the listed sites (Table 5.1) provides information on the techniques used, some of the remediation results, and the time frame for the process.

I also provide a list of some of the plants currently used for phytoremediation in a table format that shows the plant species, the plant mechanism for remediation, and the contaminants that they are know to remediate. This plant list is only a partial compellation of what is used and hundreds of other plants are currently being researched for remediation potential. It is exciting to see so many options, many of which are already commonly found in our designed landscapes.

Current landscape architects that are finding a niche for themselves on phytoremediation projects are discussed as well as their contribution to expanding the field of landscape architecture to include projects that were formerly the domain of the Environmental Engineer. I further explore the potential opportunities for Landscape Architects in redevelopment projects with remediation needs, assisting city and state governments to meet their goals, and in designing land-use codes. The importance of understanding the complexities of phytoremediation is important if landscape architecture is to take full advantage of these many opportunities and open up a new avenue for the profession.

Method of Inquiry- My primary resource was the World Wide Web. I found many online journals, newspaper articles, governmental agencies, and organizations that have data from actual sites utilizing phytoremediation. From a colleague at the firm I intern for, I was given several online sources for databases and a “listserv“ from a University that I joined. From this listserv, I can keep up on the latest techniques for phytoremediation that are being researched all over the world as well as educational opportunities in this field. I also found my two photography contributors from this listserv and they have also provided me with very useful information on phytoremediation when I had site-specific inquiries of their projects.

Results and Conclusions- Many of the results and conclusions were discussed in some detail in the previous paragraphs regarding the “Relationships Investigated”. As an overview, I will say that as the country expands and many cities find that they have to meet the increasing demands and local population growth projections, they will have to look towards in-fill projects to meet their needs. Unfortunately, many of these sites have some degree of contamination that renders them unsafe for use in their current state. There are government monies to be had, though, to help with the costs of restoring these sites and if landscape architects choose to educate themselves on phytoremediation techniques and project management requirements for these particular sites, they will be able to expand their professional repertoire into a leading or a support role in projects that are currently the sole domain of the Environmental Engineer. Landscape architectural services would not be of use on all contaminated sites, but there are many locations that will be redeveloped into public parks or open space in which the landscape architect can play an integral role as designer, project manager, public/government liaison, and even initiate policy reform for in-fill projects. This could be an exciting new avenue for landscape architecture if those in the profession choose to take advantage of the opportunities.



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