Cleanup professionals in the United States and Europe are becoming more interested in identifying best practices to help reduce the environmental footprint of contaminated site cleanups. The concept, called green remediation, is the practice of considering all of the environmental effects of contaminated site remedy selection and implementation, then incorporating options to maximize net environmental benefit of cleanup actions.

As its name suggests, green remediation centers on the second of four phases of sustainable revitalization:

1. Deconstruction, demolition and removal
2. Cleanup, remediation and waste management
3. Design and construction for reuse
4. Sustainable use and long-term stewardship.

Green remediation builds on environmentally conscious practices already used across business and public sectors by seeking ways to adapt and adopt them to cleanup projects, regardless of the regulatory framework.

This means that we must re-examine our usual ways of doing business, better coordinate our cleanup and reuse planning early during a project, and find more opportunities to conserve natural resources and energy.

Core elements of green remediation that should be considered at contaminated site cleanup projects include:

• Energy requirements to power treatment systems Increase system efficiencies, use renewable energy sources and incorporate innovative approaches such as combined heat and power systems to minimize the carbon and energy footprints.
• Air quality Use clean diesel equipment, employ dust mitigation practices and minimize fugitive emissions from treatment systems to reduce sources of air contaminants.
• Water requirements and impacts on water resources Minimize freshwater consumption, recycle water whenever possible and prevent impacts on water quality in nearby bodies of water.
• Land and ecosystem impacts Use minimally invasive technologies such as in-situ treatment or passive-energy technologies where appropriate; reduce project impacts such as noise and light pollution; and avoid the disruption of natural habitats or consider eco-restoration.
• Material consumption and waste generation Adopt technologies that minimize waste generation and recycle materials used or generated on the project.
• Long-term stewardship actions Install renewable energy to power long-term cleanup systems, use passive sampling approaches and integrate cleanup and reuse designs when cleanup actions involve long-term stewardship requirements.

Examining greener practices used elsewhere is one of the best tools for identifying opportunities in your own operation.

Ground water treatment at the former Nebraska Ordnance Plant in Mead, Neb., is one of the earliest examples of renewable energy used specifically for site cleanup. Since 2004, a 10-kW retrofit wind turbine has powered groundwater circulation wells for aboveground air stripping and ultraviolet treatment. Curt Elmore, a University of Missouri-Rolla researcher for the wind system, estimates that the utility grid-connected wind turbine has reduced electricity consumption of the treatment system by 26 percent.

“Much higher energy savings could be reached through upfront design of a groundwater treatment system intended to operate with renewable energy, including better designs for weather-proofing,” says Elmore.

Another excellent example of green remediation is demonstrated by a range of passive, energy-efficient methods used at a two-acre orchard near Crozet, Va., where soil is contaminated with arsenic, lead and pesticides.

The property owner “feels a real close connection to the property,” prompting him to take responsibility and work closely with EPA Region 3 to clean up the site. The primary remedy, phytoremediation, includes fern plantings maintained by two methods of irrigation during dry spells. The first relies on gravity to divert water from a hilltop spring to a 4,000-gallon tank, from which water is further fed by gravity for drip irrigation. In other fern plots, a 390-watt photovoltaic system powers a low-flow pump that extracts water from the bottom of the hill and diverts it to a storage tank, which is also used for gravity-fed drip irrigation. During wet seasons, water is recovered and stored for later use.

“The goal is not to be green. Our goal is to protect public health and the environment. This alternative technology allows us to do that while generating less waste and building a greener atmosphere,” says Myles Bartos, EPA Region 3 on-scene coordinator, in the EPA video “Crozet Phytoremediation.”

Federal and state agencies, as well as other organizations, are working to identify and document green remediation practices and encourage their use by removing technical and other barriers. For example, the EPA is working on a comprehensive assessment of the greenhouse gas contributions from Superfund cleanups nationwide to provide context on the relative importance of greenhouse gas emissions from cleanup activities as compared to other sources of emissions. A common goal shared by many agencies is to develop tools that help decision makers and other stakeholders make more informed decisions on green remediation opportunities at contaminated site cleanup and redevelopment projects. The EPA is sharing information on ways to implement best practices and case studies of greener operations at http://www.clu-in.org/greenremediation. The site will evolve as green remediation becomes mainstream and the industry works together to maximize the net benefit of contaminated site cleanups.

Carlos Pachon is a senior program analyst with the Office of Superfund Remediation and Technology Innovation in Washington, D.C. Any views expressed in this article are those of the author and do not necessarily represent the views of the U.S. EPA.