Sustainability in Remediation Projects

Sustainable remediation can be defined as remediation that addresses the sustainability triple bottom line. A term that is commonly used with sustainable remediation is green remediation. This remediation focuses on the environmental aspect of sustainability, mostly concerned with lowering the environmental footprint of a remedial action.

Several publications address sustainable remediation in more detail and are good follow-up readings after the reader is comfortable with the many technologies used in remediation.

• • Green and Sustainable Remediation: A Practical Framework (ITRC 2011 a);
• • Green and Sustainable Remediation: State of the Science and Practice (ITRC 2011b);
• • Green Remediation: Incorporating Sustainable Environmental Practices into Remediation of Contaminated Sites (U.S. EPA 2008); and
• • Sustainable Remediation of Contaminated Sites (Reddy and Adams 2015).

An easily accessible tool for evaluating remediation sustainability is the Sustainable Remediation Forum (SURF) Metric Toolbox for evaluating sustainability during the life of a site investigation and remediation project (Butler et al. 2011). This toolbox can be found at https://www.sustainableremediation.org/guidance-tools- and-other-resources and is composed of a series of tables for several stages of the remediation process: investigation, remedy selection, design, and construction. Each table contains descriptions of objectives, metrics, implementation guidance, benefits, and challenges for implementing sustainable parameters.

Environmental Sustainability

Environmental sustainability goes beyond the environmental objectives for the contaminated site and fosters a decrease in the environmental footprint of the remedial action. For example, reducing the environmental footprint would decrease emissions of greenhouse gases and the acquisition of raw materials for the remediation strategy.

A common way of tracking the environmental footprint of an activity is to conduct an environmental life cycle assessment (LCA) (U.S. EPA and SAIC 2006). An LCA requires four stages of activities:

• • Goal definition and scoping,
• • Inventory analysis,
• • Impact assessment, and
• • Interpretation of results.

LCA is a data-driven and data-intensive process and requires computer tools and data inventories. A complete LCA quantifies the environmental impacts on the following categories:

• • Global warming by analyzing data on greenhouse gas emissions;
• • Stratospheric ozone depletion by analyzing data on ozone-depleting chemicals;
• • Acidification by analyzing data on the release of sulfur and nitrogen oxides (SO_x and NO_x);
• • Eutrophication by analyzing data on the release of nitrogen and phosphorus compounds;
• • Photochemical smog by analyzing data on non-methane hydrocarbons;
• • Terrestrial toxicity by analyzing data on the release of chemicals to rodents (a remediation project in and of itself would reduce this impact but potentially cause other impacts on this list);
• • Aquatic toxicity by analyzing data on the release of chemicals toxic to fish (a remediation project in and of itself would reduce this impact but potentially cause other impacts on this list);
• • Human health by analyzing data on the release of chemicals toxic to humans and released to air, water, and soil (a remediation project in and of itself would reduce this impact but potentially cause other impacts on this list)-,
• • Resource depletion by analyzing data on minerals and fossil fuels used
• • Land use by analyzing data on wastes disposed to landfills; and
• • Water use by analyzing data on water used or consumed.

The takeaway message here is that cleaning up the environment can cause adverse effects on the environment. For example, remediating a site rids it of toxic chemicals but may contribute to more greenhouse gases. The EPA conducted a study on all National Priority List (NPL) sites using the five remediation technologies listed in Table 9.3 and found that from 2008 to 2030 (data were extrapolated) those sites are estimated to spend over $1.4 billion on electricity and emit over 9 million metric tons of CO,, the equivalent of operating two coal-fired power plants for one year

TABLE 9.3

Estimated C0₂ emissions from remediation technologies at NPL sites using five technologies over 23 years (U.S. EPA 2008)

(U.S. EPA 2008). If reducing C0₂ emissions is a priority, then one way to practice environmentally sustainable remediation would be to consider using more passive techniques, such as enhanced bioremediation, phytoremediation, monitored natural attenuation (MNA), and engineered wetlands (which combine processes of bioremediation, phytoremediation, and MNA) as long as they meet the required remediation goals.

It may come as no surprise that remediation process optimization (RPO) covered in Chapter 8 overlaps with concepts of sustainable remediation. For example, the United States Navy conducted a study on remediation sites at its bases within the context of optimization and concluded that after a certain amount of contaminant mass is removed, the other environmental impacts caused by the remediation system (e.g., emissions of criteria air pollutants and greenhouse gases (GHG), changes in land and ecosystem, and impact to the community and workers due to noise and safety) were not worth additional reduction in contaminant mass (Figure 9.5) (NAVFAC Optimization Workgroup and Battelle Memorial Institute 2012).

Social Sustainability

Many tools and methodologies are available for remediation professionals to track the societal impacts of their projects (Harclerode et al. 2011). Although not used consistently throughout the remediation profession, the leading social indicator categories can be summarized as:

• • Health and safety of remediation workers and the neighboring community;
• • Economic vitality of the community through the hiring of local workers, outreach activities, and land redevelopment;
• • Stakeholder collaboration so that project workers can detect unintended

consequences before they happen;

FIGURE 9.5 Data visualization to detect adverse impacts on the environment by remediation systems. (Source: NAVFAC Optimization Workgroup and Battelle Memorial Institute 2012.)

• • Benefits to the community at large by improving the area for the population’s activities;
• • Undesirable community impact minimized, such as traffic, noise, and dust;
• • Social justice by continuing to make affordable housing available, providing jobs to local residents, and provide new, clean gathering spaces;
• • Value of ecosystem services and natural resources capital re-established by cleaning contamination and restoring ecosystems and water features;
• • Risk-based land management and remedial solutions to address community-specific health concerns;
• • Regional and global societal impacts alleviated by performing sustainable remediation that reduces negative effects on public health and climate; and
• • Contribution to local and regional sustainability policies and initiatives by performing state-of-the-practice sustainability activities, such as using renewable energy sources, employing local residents, and performing health risk analysis specific to the local community.

Something that becomes apparent after studying the social indicators above is the overlap among social, environmental, and economic indicators. However, the overlap does not mean one can ignore one or more of the three pillars of sustainable remediation. Sustainable projects require an intentional pursuit and demonstration of the achievement of all three pillars.

Economic Sustainability

Economic sustainability in remediation consists of projects that generally can optimize cost expenditures and also benefit the local community economically. The SURF Metric Toolbox (SURF 2020) cites the following indicators for economic sustainability in a range of site activities.

Remedy Selection (Feasibility Study phase)

• • Create jobs in the community, measured by new space for commercial development or recreation;
• • Select minimum essential materials;
• • Minimize the timing to achieve future land use; and
• • Minimize off-site disposal of solid waste.

Remedial Design

• • Optimize the design to reduce the number of wells, pumps, and chemicals;
• • Conduct optimization designs throughout the life of the project;
• • Maximize the future land use and area of the project;
• • Increase local jobs based on redevelopment of the area;
• • Minimize and consolidate transportation to and from the site to reduce fuel costs;
• • Design for minimum essential materials for construction; and
• • Use on-site renewable energy to reduce operational costs.

Remedial Construction

• Minimize and consolidate transportation to and from the site to reduce fuel

costs;

• • Ensure the correct equipment size for tasks to balance cost and efficiency;
• • Minimize idling time of equipment;
• • Reuse site construction materials where possible;
• • Purchase from vendors that have sustainable programs and policies;
• • Use energy-efficient systems and equipment for field buildings; and
• • Reduce on-site risk of injury or accidents.

Economic sustainability indicators are common-sense good practices when an environmental professional is intentional in pursuing sustainability. This requires good planning, a well-functioning project team, and good relationships with stakeholders, including construction contractors, the project owner, government oversight personnel, and the local community.