Contaminated land/sites

The U.S. National Environmental Policy Act of 1969 required careful analysis of the consequences of any federally funded project. The Resource Conservation and Recovery Act (RCRA) of 1976 established guidelines for handling, transport, and hauling of hazardous materials, such as required in cleanup of soil contaminants. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 established, for the hrst time, strict mles on legal liability for soil contamination. CERCLA stimulated identihcation and cleanup of thousands of contaminated land sites, and consequently raised awareness of property buyers and sellers to make soil contamination a focal issue of land use and management practices (US-EPA 2007c). 

You have been asked to analyse a contaminated land site for a range of metals by employing an atomic spectroscopic technique that requires you to convert the soil samples obtained into aqueous form using concentrated acid. Which approach would you use ... 

With the new risk-based approach to assessing contaminated land sites, there are a number of new areas of analysis that are required by risk assessors. 

Common asbestos containing materials that may be found in contaminated land sites... 

The acceptability of the risks presented by contaminated land sites is not a... 

In this chapter, three aspects of contaminated land management are considered. Firstly, the identification of contaminated land sites is discussed. Secondly, the process of site assessment is considered. Thirdly, methods for sampling and testing of contaminated land are outlined. 

A variety of instrumental analytical techniques are used to measure contaminants in extracts of both soil and water from contaminated land sites. 

It must be appreciated that contaminated land sites can exhibit pollution liabilities of two basic forms. There can be liabilities arising from pollution to people and property off site—so called third party liabilities—and also liabilities relating to pollution of the site itself and the consequential need to clean up the site. The second liability may, and in some cases is likely to, lead to damage to people or property off site. 

There are numerous reasons why such policies should be considered, not just for reclaimed contaminated land sites, but also for sites where contamination is not suspected. Some obvious reasons are ... 

The cast of a survey of a contaminated land site, together with associated sampling and analysis, may run into hundreds of thousands of pounds. The remediation of the site as a result of the consultant s sampling, analysis and advice may cost many millions of pounds. The value of the land, once it has been developed, may be many tens or indeed hundreds of millions of pounds. If the consultancy was negligent in the way in which it took the samples or caused the analysis to be undertaken, in their assessment of the results of the analysis, or in the way in which they proposed the site should be cleaned up, and as a result the site is faced with a further clean-up bill of millions of pounds, therefore making the site in the short term worthless, who is to pay ... 

Assessing the extent of pollution in contaminated land sites is one of the most commonly faced environmental problems. Sampling is critical to make proper assessment. Obviously, samples will be taken to represent parts of the site where contamination is expected, or where contaminants are expected to be transported. You should examine surface soil samples, core samples at various depths, runoff in nearby streams, rivers or lakes, sediments, and vegetation from surface aquatic systems and at the land site. 

Cement is used in a variety of applications in which it comes into contact with the geological environment. In hydrocarbon well-bores and mine-shafts it is a principal component of the engineered environment adjacent to the host geology. In many radioactive waste (or rad-waste ) concepts and some landfill and contaminated land sites, cementitious material forms part of the system of barriers between waste and the biosphere. Its barrier properties include high sorption capacity, potentially low permeability, and the ability to condition its porewaters to a highly alkaline pH. This is particularly important around radwaste repositories where high pH lowers the solubility of a number of the key radionuclides and also slows the corrosion of the metal canisters in which the waste may be placed. 

Another area of mutual interest is that of redevelopment of contaminated land sites. The industrial legacy of the United Kingdom has left many areas of land polluted and unsuitable for both current and future use. Land may be contaminated not only by substances occurring as a result of human activity, but also by natural substances occurring in rocks and soil. The Agency estimates that some 300,000 hectares of land may be arfected either by industrial or naturar contamination. 

Xanthates are used in a froth flotation process of soils contaminated with mercury. The soil to be treated is mn through hydrocyclones, and the slurries are flocculated, dewatered, and removed to a secure landfill. The effluent water is recycled. The process is suitable for treating industrial land sites contaminated with mercury droplets (115). 

Many of the factors that influence the c.xtcnt of contamination are site specific, cither climatic or hydrogeological. Other factors that influence the extent of contamintition relate to land surface features such as topography or dcNclopmcnt, which determine exposure routes. Additional important... 

Many policies and practices have been adopted by European countries for the management of contaminated sites. Information about the various national polices, the technical approaches for risk assessment, and the progress of rehabilitation activities in Europe has been compiled in the framework of two European networks—CARACS (Concerted Action for Risk Assessment for Contaminated Sites) and CLARINET (Contaminated Land Rehabilitation Network for Environmental Technologies)—which were funded by the European Commission. A detailed description of European national policies can be found in relevant publications2 3 and in the CLARINET website (http //www.clarinet.at). 

Source From NATO/CCMS, Evaluation of Demonstrated and Emerging Technologies for the Treatment and Clean Up of Contaminated Land and Groundwater, NATO CCMS Pilot Study, Phase III, 1999 Annual Report, EPA 542/R-99/007, no. 235,1999 Ferguson, C. and Kasamas, H., Eds., Risk Assessment for Contaminated Sites in Europe, Vol. 2. Policy Frameworks, LGM Press, Nottingham, UK, 1999. With permission. 

Loibner A, Jensen J, Ter Laak T, Celis R, Hartnik T (2006) In Jensen J, Mesman M (eds) Ecological risk assessment of contaminated land decision support for site specific investigations. RIVM report 711701047. Bilthoven, The Netherlands, p 19... 

There are a wide range of bioremediation technologies either in use or proposed for use on oil/gasoline-contaminated land [301, 319], and these can be divided into two broad groups. In situ techniques treat the contamination at the site of the pollution event, whereas ex situ techniques remove the contamination from the ground and transfer it to another location for treatment. The use of in situ treatment is often preferable in terms of financial considerations, due to the cost of moving large quantities of soil [20]. Some novel approaches to the problem of hydrocarbon contamination of contaminated aqueous-solid phase environments is the use of (1) gas-liquid foams to enhance in situ bioremediation, and (2) biostimulation, as follows. 

The regional temperature variations, rainfall, patterns, groundwater flow characteristics, explosive type, explosive concentration, presence of other contaminants, land value, and other regulatory requirements can affect the wetland s cost. Constructed wetlands may not be financially viable at aU sites (D20499J, p. 2 D20503Y, p. 30). 

Ellis, B. (1994). Reclaiming contaminated land in situ/ex situ remediation of creosote- and petroleum hydrocarbons-contaminated sites. In Bioremediation Field Experience, ed. P. Flathman et al., pp. 107-43. Boca Raton, FL CRC Press. 

Industrially contaminated soil. The investigation, remediation (where necessary) and re-use of derelict and industrially contaminated land is a major concern, particularly in developed countries where legislation exists or is being enacted to promote re-use of brownfield sites and discourage greenfield development. 

There is increasing interest in the use of sequential extraction as a component of a site investigation and in the development of a suitable remediation strategy for contaminated land (Pierzynski, 1998). 

International harmonization of soil quality standards (SQSs) has been discussed in the CARACAS (Concerted Action on Risk Assessment for Contaminated Sites in the European Union, 1995 to 1998) and CLARINET (Contaminated Land Rehabilitation Network for Environmental Technologies, 1998 to 2001) concerted actions (Vegter et al. 2003), and a form of the Soil Framework Directive is still under review by member states in the European Union, so the present guidance is both timely and relevant. 

---