Contamination and Remediation of Sites - Essay Example

Contamination And Remediation Of Sites Brownfields, as defined by federal government are “abandoned, idled or underused industrial and commercial properties where expansion or redevelopment is complicated by real or perceived environmental contamination.” Such contamination sites can be Brownfield sites or any other sites needing some sort of remediation for using then either for commercial, residential or any other purpose. These can be former service stations, abandoned railroads, warehouses or air strips which can be found anywhere in the country but are primarily concentrated in urban areas.1 The expansion or redevelopment of such sites may sometimes be too complicated due to various environmental contaminations. The contaminated land may be contaminated either by low or high concentrates hazardous wastes or pollution but are potential enough to be reused after remediation processes. But the land which is severely contaminated by such contaminants does not come under brownfield classification. It has also been seen that there are few cases where the owners are “not willing to transfer the brownfield or put it into productive reuse”, as those of Mothballed brownfields in United States. It is because these may cause blight, threaten public health and the environment and even hold back economic development and revitalization i.e. staking social, economic as well as environmental wellbeing.2 A Brownfield Relic Serves as a Statue in Park In Atlantic Station, Atlanta Georgia. The extent of cleaning and the costs involved in the remediation process wholly depends upon the type, amount and area of contamination. The standards of cleanup adopted also influence the cleanup process. For example the clean up standards would be more stringent if the property or land is to be used for residential purposes and less strict if to be used for industrial purposes as the exposure to the contaminants would be quite less in this case. And the types of the contaminants too determine the cost while clean up process. For example if the groundwater of the site is found contaminated the cost of remediation process will be much higher than if just the soil is found contaminated. The costs of the cleanup to the property owner can also be contributed by other parties such as previous owners if they too are found responsible for contributing towards the contamination. (footnote 1) It has been seen that due to costs involved in the safe standards of cleaning processes of contaminated sites, most of them usually sit idle and unused for huge number of years. It is because the even the worth of the property after cleanup is much less than the costs of remediation processes involved. But due to lack of availability of the land in present times, especially in the highly populated areas, the redevelopment of brownfileds is seen becoming common in 21st century. The methods of studying the contaminated land have also become more established and sophisticated. Various federal and state government programs have been started today to assist the developers who are interested in remediation process of their lands. To move the brownfield redevelopment process forward, even many localities have contributed to the clean up costs. Mostly among the contaminants found on the contaminated sites may include hydrocarbon spillages, heavy metals as lead, tributyltins and asbestos; pesticides and other solvents. But the amount of contamination can vary from no contamination to high contamination. And the type and amount of contamination will too vary from site to site. It can “range from a dilapidated but harmless property to highly toxic Superfund site.” The clean up process can also yield various benefits as the opportunity to protect health, new jobs, increase the tax base, renew obsolete civil infrastructure and to revitalize inner-city neighborhoods. According to Lange and McNeil (2004), the two major outcomes that would define the success of redevelopment of contaminated sites are the creation of long term jobs and the increase of local real estate and income tax bases. Now the researchers have even focused their attention towards other important related factors as environmental justice, risk liability and land use issues.3 The environment agencies are working hard to bring more and more land for sustainable use. Concentrated development of brownfield sites can encourage more sustainable lifestyles and provide the opportunities to recycle the whole contaminated land, clean-up them and even assist environmental, social and economic regeneration. Such reuse of contaminated sites also saves greenlands and countrysides hence reducing the pressure although the costs involved in clean up processes is quite and the demands of the type of land quite different. But the changing population patterns and demographics have encouraged the reuse of contaminated sites although after needed remediation. Some of the planning guidance in England imposes priority on brownfield redevelopment (PPG3) whereas others (PPG25)4 too give priority to the development in low-risk flood areas. So, there is a never ending confusion prevailing regarding treating flood risk while redeveloping brownfields. It is expected that, “the area of land at risk of flooding will increase substantially by 2050 due to climate changes.” The engineers are also using some of the solutions to remediate contamination as “encapsulation of contaminated soil left in situ, preamble reactive barriers, or bentonite walls” but these may not be appropriate if the site is to be subject to inundation by flood waters. The core reason of the contamination of the sites can be lack of economically suitable remediation methods or long term contamination by previous users. There are several methods to assess the risk and to take upon needed remediation methods. These all are taken for protecting health and environment from contamination. 5 Remediation of Sites Netherlands Brownfield Remediation Various governments are today promoting the redevelopment of brownfileds or any contaminated industrial or other site, taking suitable remediation methods. These offer great development opportunities having most of the centrally located infrastructures in place. But these are ought to suffer from serious contaminations as groundwater pollution which can then result in liabilities for the owners, huge cost involving remediation as well as the negative impacts and resulting lower land value. The remediation techniques range from being traditional to civil engineering ones which are far more sophisticated. There are various practical and cost effective solutions for treating contaminated sites which can be implemented within the industrial premises as well. The type and the amount of contamination of the site and other risks determine the methods to be used in specific site. The methods of remediation can be undertaken either on site or off-site. Off site processes involve “digging up and treating the material, so as to control the application and process large volumes. On-site remediation can be done without excavation, stockpiling and handling of processes, hence simultaneous with construction.”6 Chart for Services involving Land and Building Recycling: Environmental Site Assessments Permitting and Regulatory Interface Soil and Groundwater Investigations Remedial Design Strategies Underground Storage Tanks Hydrogeological and Contaminant Modeling Environmental Sampling and Reporting7 Among various site remedial systems the ones to be used are implemented after site data collection, scientists’ analysis, understanding the nature and the amount of contamination, migration pathways and various other physical and chemical properties determining the alternatives for site remediation. The contemporary statistical techniques are perfect to define the realistic concentrations and volumes of the contaminants present at a site. These also help in understanding as to how these contaminants may be transported to environment and human body. The key point of all such research and study is to estimate the risk and potential costs associated with the remediation and its use. One of the most practical and affordable clean up process is always the risk-based cleanup approach that too within the regulatory framework. This helps in achieving the most realistic and acceptable results with substantial reduction in remediation costs. Here is an example of the same used by HSA Engineers and Scientists. 8 Garage Remediation of sites is done depending upon the contamination type and amount of the site. It may vary from site to site. Although engineers have evolved various cost effective and new methods of remediation but sometimes the traditional methods are considered equally vital depending upon the contaminated site. Volatile and semi-volatile compounds can be removed by a traditional physical treatment process, the ‘soil vapor extraction’ method. Groundwater can also be treated by this method using a modified process known as ‘dual-phase vacuum extraction’. Another physical treatment that can be used is ‘soil flushing’. It involves the passing of water through the contaminated soil using series of injection and abstraction wells, to remove the contaminants. The contaminated water is then discharged into the sewer. Another similar traditional remediation method is ‘soil washing’. The biological treatment, bioremediation is other traditional remediation method which helps in enhancing environmental conditions for microbial activity in the soil. It breaks the complex hydrocarbons into simpler forms which are no more harmful. It is a very simple method, quite effective on simple and intermediate chain-length alkanes. Bioremediation can be undertaken ex situ, treating soil at ground level with biopiles. It can also be undertaken in situ applying nutrients directly into the soil well points. Even the groundwater can be treated in the surface mounted bioreactor with the effluent rich in micro-organisms, nutrients and oxygen. If the soil of the site is contaminated it can be treated by using various chemical treatments as well, though a bit costly but hugely effective. It is similar to soil washing; however the chelating agents and surfactants are added to the water. Another method is the one involving chemical destruction. These are limited to the nature of soil or groundwater contaminants that can be treated by this method. This method is also used to remove oils, tars, polyaromatic hydrocarbons, cyanides and other heavy metals. Conventional remediation methods of cleaning ground water involve separation, microbiological and gravitational methods. Ground water contamination with pesticides and heavy metals may be treated using anaerobic digestion or activated sludge processing. Gravitation separation methods involve sedimentation, floatation and centrifugation. Thermal remediation methods as incineration involve combustion of contaminated soil or water. It is mainly effective on the sites with hydrocarbons although the wastes produces mat contain high concentrates of ash which may still need disposal. Civil engineering methods can deal with a wide range of contaminants using well established engineering systems and contract procedures. Encapsulation can be used to remediate wide range of harmful compounds. Other thermal remediation processes are soil fractionation, vitrification, excavation and removal, hot air and steam sparging, stabilization and solidification techniques etc. (refer footnote 6) Most of these remediation methods are cost effective, providing protection to the environment, allowing safe development of the sites and reducing prosecution. “Remediation technologies are developing rapidly from there bases in science and engineering”. Today most of the construction companies as Bristol, UK are releasing the need to develop the remediation technologies in supplement to dig and dump approach to contaminated land.9 These traditional and engineering remediation solutions have deep social, environmental and economic impacts. But every project should make it a point that negative impacts of remediation should not exceed the benefits of the project. Remediation is directly related to environmental and health risks and also the construction measure adopted later on. The objectives of the remediation depend upon the compromise between the desired aim of environmental quality and the site-specific boundaries. These objectives usually represent the ‘core’ of the remediation project. Most of the times, these core objectives do not consider ‘overall’ environmental, social and economic values of the remediation process. For example the overall environmental, social or economic impacts and benefits are not clearly addressed. Such impacts or objectives can be termed as ‘non-core’ objectives. (See in fig: 1) The various environmental effects include avoidance of the transfer of pollutants and nuisance to local neighborhoods; economic effects include the value of money needed and the other additional values of the project as investors and planners; social effects include greater public and community interests. Today even these wider effects of remediation are becoming increasingly important due to all the mentioned pressures. The overall value in the context of sustainable development is the combination of all these environmental, social and economic values. It is thus, a never ending debate upon “sustainable remediation”.10 Figure: 1 United States Environmental Protection Agency (EPA) has studied and regulated various pollutants in the air, water and land due to remediation. It has also suggested to include all these harmful impacts in its risk analyses which would also reduce the expenses of the remediation process. It has also launched major construction programs as construction of sewage treatment plants, remediation of hazardous waste sites etc.11 Today various agencies are striving towards the cleanup programs using natural resources and energy efficiently. This would surely reduce harmful impacts on the environment by minimizing pollution and reducing wastes as much as possible. “EPA supports the adoption of green remediation as the practice of considering all environmental effects of cleanup actions and incorporating strategies to maximize the net environmental benefit”. The core elements to be considered to evaluate the cleanup project are: Energy requirements and the economic and environmental issues involved. Air emissions. Impacts in land and ecosystems. Waste generation. Water requirements and the associated impacts on the water resources. EPA is also placing greater emphasis on remediation approaches which may contribute towards reduces energy consumption and GHG emissions. It is done by designing treatment systems with optimum efficiency, using renewable sources as wind and solar energy. Using alternative fuels as bio fuels, generating power from byproducts as methane gas or waste and by participating in power generation etc. All these methods would surely contribute towards the environmental factors and social impacts hence maximizing environmental, social and economic benefits of remediation. 12 Chart of various environmental conscious practices of remediation: Pollution Prevention Waste management Reuse and recycling Using eco-friendly products Water conservation and reuse. Water management. Sedimentation and soil erosion control Green-space allocation etc. Chart for various Key Services in Remediation Flood Risk Assessments PPS25 (England), TAN15 (Wales) and SPP7 (Scotland) Contamination Land Remediation Strategy and Validation Services. Traffic Impact Assessment and Green Travel Plans Sustainable Development expertise Air quality and Noise impacts One of the most suitable examples can be sited here. The site in the picture was subjected to serious contamination. Here, in Ashlands, Portishead were dumped the ash produced by the power stations form over 50 years. Prior to its reuse the site required careful management of contaminated material and significant modifications in the topography. Surface water solutions, flood risk management and foul water solutions were carefully adhered to by the team members. In addition to all development and construction even the road infrastructure in the form of both main and shared surface highways were designed. A perfect remediation indeed!13 Environmental Capping Layer works following the installation of Matins drainage. (Remediation) Piling Foundation for New Homes in the Project Further (Reuse of the site) Numerous private and public sector organizations play a vital role in remediation of brownfield sites, industrial or any other reusable contaminated site. The common ones seen taking initiatives in remediation are state environmental agencies, planning agencies, state economic agencies and other citizen and community group, commercial lenders, legal counsels, technical consultants, local government agencies, developers, real estate professionals, investors, federal government agencies, local community development corporations and many others. All these take the best possible remediation solutions according to the requirements of the particular site depending upon the type of the contaminations on that site. (refer footnote 1) Sources: Brownfileds FAQ. Brownfields Center at the Environmental Law Institute. Brownfieldscenter.org December 5, 2008. EPA Government. Motheballed. Thursday. November 27, 2008. December 5, 2008. All Academic Research. Citizen Participation in Brownfield Redevelopment: A Comparative Case Study. 2008. December 5, 2008. Brownfield Land Redevelopment: Position Statement. Key Issues. Environment Agency. December 4, 2008. December 5, 2008. Chemistry and Industry. Find Articles. Findartices.com. Rhodes. Steve. February 3, 2003. December 5, 2008. Environmental, Health and Safety. SSM Group. ssmgroup.com December 5, 2008. Site Remediation. HSA Engineers and Scientists. Hsa-env.com. 2005. December 5, 2008. IMS Marketing Communications. Bristol. UK. Bioremediation technologies. International-cleanup.com. December 5, 2008.< www.international-cleanup.com> Wider Impacts or Sustainability. Environmental Technology Limited. United Kingdom. Eugris.info. Bardos. Paul. December 5, 2008. Journal Article. Hazardous Waste Site Cleanup and Neighborhood Redevelopment: An Opportunity to Address Multiple Socially Desirable Goals. Questa.com. Greenberg, Michael. Schneider Dona. Vol. 23, 1995. December 5, 2008. Green Remediation: Incorporating Sustainable Practices into Sire Remediation. Environmental Protection Agency. astswmo.org. United States. February 2008. December 5, 2008. Supporta Professional Services. supportaps.com. Ashlands. Portishead. December 5, 2008. Read More