This post is by Brendan Sisombath, a senior Biology major at the University of St. Thomas.
Developing soil remediation strategies is becoming an important undertaking in urban environments. Many urban soils contain high concentrations of contaminants such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals such as arsenic, lead, and mercury (McClintock 2012). This presents a concern as ingestion of pollutants via vegetable uptake, contaminated aerosols, and soil adhering to unwashed produce or hands, threaten human health. (Finster et al. 2004, Wortman and Lovell 2013). In many cases, abandoned sites may remain unusable until contaminates are remediated (Hazelton and Murphy 2011). For example, development of the former location of a Ford Plant in the city of Saint Paul cannot move forward until the soil on site meets industrial standards set by the Minnesota Pollution Control Agency (Melo 2014). Current strategies for managing these soils often include removing the soil and replacing it with healthier soil. However, this remains a costly solution and generally only occurs in higher income areas (McClintock 2012, Wortman and Lovell 2013). Forthcoming remediation strategies must be widely applicable and cost effective in order to remain relevant.
The empty 125 acres of land land where the Ford Plant once stood in St. Paul (Pioneer Press: Ben Garvin)
Application of compost to damaged soils is becoming a widely applicable strategy for soil remediation. Compost improves both chemical contamination and physical degradation in soils, allowing for improvement of many different soils on multiple levels. Application of compost has been shown to reduce bioavailability of lead and other heavy metals (Wortman and Lovell 2013). In addition, compost increases aggregate stability of damaged soil suggesting decreased soil erosion and increased moisture retention (Hazelton and Murphy 2011). Furthermore, the materials to produce compost, both at a large scale and a small scale, are widely available. In cities, approximately one quarter of the food imported is never consumed (Kantor et al. 1997). Food waste and other municipal waste products can be utilized to produce compost for degraded urban soils. There is much potential for members of the community to use their waste products to create compost and contribute to the health of their own soils. Instead of relying on expensive construction projects to be completed, urban communities can create compost and combine it with the contaminated soils to actively work towards their own solution.
In addition, compost is a cost effective remediation strategy. It is estimated that removing contaminated soils and replacing it with healthier soil would cost approximately $130,000 per hectare. Applying and mixing compost with contaminated soils would only cost an estimated $60,000 per hectare (Wortman and Lovell 2013). Furthermore, economic benefits of compost can be expanded when considering its ability to reduce environmental impacts of cities. Composting municipal waste has the potential to greatly reduce nutrient runoff from urban landfills and reduce expensive eutrophication problems. In addition, there is opportunity to use compost to scale up urban agriculture. Plants themselves are also able to remove heavy metals from the soil and store them into its shoot tissues in a process called phytoremediation. This synergetic approach would bolster the remediation power of compost while providing local fo
Developing soil remediation strategies is becoming an important undertaking in urban environments. Many urban soils contain high concentrations of contaminants such as polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and heavy metals such as arsenic, lead, and mercury (McClintock 2012). This presents a concern as ingestion of pollutants via vegetable uptake, contaminated aerosols, and soil adhering to unwashed produce or hands, threaten human health. (Finster et al. 2004, Wortman and Lovell 2013). In many cases, abandoned sites may remain unusable until contaminates are remediated (Hazelton and Murphy 2011). For example, development of the former location of a Ford Plant in the city of Saint Paul cannot move forward until the soil on site meets industrial standards set by the Minnesota Pollution Control Agency (Melo 2014). Current strategies for managing these soils often include removing the soil and replacing it with healthier soil. However, this remains a costly solution and generally only occurs in higher income areas (McClintock 2012, Wortman and Lovell 2013). Forthcoming remediation strategies must be widely applicable and cost effective in order to remain relevant.
Application of compost to damaged soils is becoming a widely applicable strategy for soil remediation. Compost improves both chemical contamination and physical degradation in soils, allowing for improvement of many different soils on multiple levels. Application of compost has been shown to reduce bioavailability of lead and other heavy metals (Wortman and Lovell 2013). In addition, compost increases aggregate stability of damaged soil suggesting decreased soil erosion and increased moisture retention (Hazelton and Murphy 2011). Furthermore, the materials to produce compost, both at a large scale and a small scale, are widely available. In cities, approximately one quarter of the food imported is never consumed (Kantor et al. 1997). Food waste and other municipal waste products can be utilized to produce compost for degraded urban soils. There is much potential for members of the community to use their waste products to create compost and contribute to the health of their own soils. Instead of relying on expensive construction projects to be completed, urban communities can create compost and combine it with the contaminated soils to actively work towards their own solution.
In addition, compost is a cost effective remediation strategy. It is estimated that removing contaminated soils and replacing it with healthier soil would cost approximately $130,000 per hectare. Applying and mixing compost with contaminated soils would only cost an estimated $60,000 per hectare (Wortman and Lovell 2013). Furthermore, economic benefits of compost can be expanded when considering its ability to reduce environmental impacts of cities. Composting municipal waste has the potential to greatly reduce nutrient runoff from urban landfills and reduce expensive eutrophication problems. In addition, there is opportunity to use compost to scale up urban agriculture. Plants themselves are also able to remove heavy metals from the soil and store them into its shoot tissues in a process called phytoremediation. This synergetic approach would bolster the remediation power of compost while providing local food products to the community, a result that may offset the cost of remediating urban soils.
An elementary school student constructing a compost pile using food waste from the cafeteria.
(http://inspiredowl.org/2010/10/25/composting-in-the-lunchroom/)
The application of compost is a developing remediation strategy that has the potential to improve the quality of urban soils at relatively low cost. Compost can be created and applied without significant expense. This strategy increases the potential for urban cities to remediate its soils and improve living and working environments. However, compost is an appealing strategy to cross environmental justice barriers and provide remediation to underserved areas in urban environments.
