The examples and perspective in this article may not represent a worldwide view of the subject.(October 2012) |
Contaminated land contains substances in or under the land that are actually or potentially hazardous to health or the environment. Areas with a long history of industrial production are known as brownfield land. Many such sites may be affected by their former uses such as mining, industry, chemical and oil spills and waste disposal.
Contamination can also occur naturally as a result of the geology of the area, or through agricultural use.
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Land can be contaminated by things like:
A requirement was placed on all local authorities in England, Wales and Scotland to investigate potentially contaminated sites and, where necessary, ensure they are remediated by Part IIA of the Environmental Protection Act 1990, [1] which was inserted by the Environment Act 1995
The regime in Part IIA did not apply to radioactive contamination, but section 78YC permitted Ministers to make regulations to apply Part IIA to such contamination. Such Regulations have been made. [2]
The Waste and Contaminated Land (Northern Ireland) Order 2007 made similar provision for Northern Ireland [3]
Section 78A(2) of the Environmental Protection Act 1990 [1] defines "Contaminated Land" as:
The Contaminated Land Report (CLR) series of documents have been produced by the Department for Environment, Food and Rural Affairs (DEFRA) and the Environment Agency, to provide regulators with "relevant, appropriate, authoritative and scientifically based information and advice on the assessment of risk from contamination in soils".
The Environment Agency has issued a number of Soil Guideline Values (SGVs) which, whilst non-binding, may be used as guidance in the environmental risk assessment [4] of land and in setting remediation targets. They should only be applied to human health assessments.
Assessment of contaminated land in the UK is predominantly undertaken under the planning system. The National Planning Policy Framework [5] (NPPF) sets out that, following development, a site should not be capable of being determined as ‘contaminated land’ under Part IIA of the Environmental Protection Act. [1] In addition, the risks from contamination should be assessed within the context of a site’s end-use and upon completion, the site should be ‘suitable’ for its new use.
A technical framework for identifying and dealing with land affected by contamination is detailed within DEFRA and Environment Agency guidance entitled Model Procedures for the Management of Land Contamination [6] (CLR11). The process can broadly be divided into three stages: risk assessment, remedial options appraisal, and implementation of remediation.
A 'phased approach' to risk assessment is encouraged within CLR11 and should typically include the following:
Should the risk assessment demonstrate that unacceptable risks to human health or the surrounding environment are likely to exist, then some remedial work will be necessary. This process involves three key stages:
Once the remedial strategy has been approved by relevant regulatory authorities then it should be implemented. A verification report should be produced upon completion of the work to demonstrate that remedial targets have been achieved. This work may include testing of remedial excavations, results of post-remedial monitoring, certification for imported material or membrane integrity testing, amongst other things. Details of ongoing/long-term monitoring may also need to be agreed at this stage, possibly under a Section 106 Agreement.
Upon completion of this process, the site should not pose a significant risk to future users or the surrounding environment and should be suitable for its end use. Once this process of site assessment has been completed successfully then any associated planning conditions can be discharged.
In urban planning, brownfield land is any previously developed land that is not currently in use that may be potentially contaminated. The term is also used to describe land previously used for industrial or commercial purposes with known or suspected pollution including soil contamination due to hazardous waste.
The United States federal Superfund law, officially the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), established the federal Superfund program, administered by the U.S. Environmental Protection Agency (EPA). The program is designed to investigate and clean up sites contaminated with hazardous substances. Sites managed under this program are referred to as "Superfund" sites. There are 40,000 federal Superfund sites across the country, and approximately 1,600 of those sites have been listed on the National Priorities List (NPL). Sites on the NPL are considered the most highly contaminated and undergo longer-term remedial investigation and remedial action (cleanups).
Contamination is the presence of a constituent, impurity, or some other undesirable element that spoils, corrupts, infects, makes unfit, or makes inferior a material, physical body, natural environment, workplace, etc.
Environmental remediation deals with the removal of pollution or contaminants from environmental media such as soil, groundwater, sediment, or surface water. Remedial action is generally subject to an array of regulatory requirements, and may also be based on assessments of human health and ecological risks where no legislative standards exist, or where standards are advisory.
The Rocky Mountain Arsenal was a United States chemical weapons manufacturing center located in the Denver Metropolitan Area in Commerce City, Colorado. The site was completed December 1942, operated by the United States Army throughout the later 20th century and was controversial among local residents until its closure in 1992.
The Sydney Tar Ponds were a hazardous waste site on Cape Breton Island in Nova Scotia, Canada.
The National Priorities List (NPL) is the priority list of hazardous waste sites in the United States eligible for long-term remedial investigation and remedial action (cleanup) financed under the federal Superfund program. Environmental Protection Agency (EPA) regulations outline a formal process for assessing hazardous waste sites and placing them on the NPL. The NPL is intended primarily to guide EPA in determining which sites are so contaminated as to warrant further investigation and significant cleanup.
Soil contamination or soil pollution as part of land degradation is caused by the presence of xenobiotics (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste. The most common chemicals involved are petroleum hydrocarbons, polynuclear aromatic hydrocarbons, solvents, pesticides, lead, and other heavy metals. Contamination is correlated with the degree of industrialization and intensity of chemical substance. The concern over soil contamination stems primarily from health risks, from direct contact with the contaminated soil, vapour from the contaminants, or from secondary contamination of water supplies within and underlying the soil. Mapping of contaminated soil sites and the resulting cleanups are time-consuming and expensive tasks, requiring extensive amounts of geology, hydrology, chemistry, computer modeling skills, and GIS in Environmental Contamination, as well as an appreciation of the history of industrial chemistry.
The Environmental Protection Act 1990 is an Act of the Parliament of the United Kingdom that as of 2008 defines, within England and Wales and Scotland, the fundamental structure and authority for waste management and control of emissions into the environment.
In the United States, an environmental site assessment is a report prepared for a real estate holding that identifies potential or existing environmental contamination liabilities. The analysis, often called an ESA, typically addresses both the underlying land as well as physical improvements to the property. A proportion of contaminated sites are "brownfield sites." In severe cases, brownfield sites may be added to the National Priorities List where they will be subject to the U.S. Environmental Protection Agency's Superfund program.
Rhizofiltration is a form of phytoremediation that involves filtering contaminated groundwater, surface water and wastewater through a mass of roots to remove toxic substances or excess nutrients.
Soil Guideline Values (SGVs) are figures which are used in non-statutory technical guidance for assessors carrying out risk assessments to determine whether land is considered ‘contaminated’ under United Kingdom law, that is “land which appears to… be in such a condition, by reason of substances in, on or under the land, that (a) significant harm is being caused or there is a significant possibility of such harm being caused…”
Land recycling is the reuse of abandoned, vacant, or underused properties for redevelopment or repurposing.
In-Situ Capping (ISC) of Subaqueous Waste is a non-removal remediation technique for contaminated sediment that involves leaving the waste in place and isolating it from the environment by placing a layer of soil and/or material over the contaminated waste as to prevent further spread of the contaminant. In-situ capping provides a viable way to remediate an area that is contaminated. It is an option when pump and treat becomes too expensive and the area surrounding the site is a low energy system. The design of the cap and the characterization of the surrounding areas are of equal importance and drive the feasibility of the entire project. Numerous successful cases exist and more will exist in the future as the technology expands and grows more popular. In-situ capping uses techniques developed in chemistry, biology, geotechnical engineering, environmental engineering, and environmental geotechnical engineering.
The Bawtry gasworks contamination involved land at Bawtry, South Yorkshire, England containing hazardous byproducts from the manufacture of coal gas. Remediation of the land was at public expense through the Environment Agency (EA), who then sought to recover the costs from National Grid Gas (NGG), then known as Transco, declaring it the "appropriate person" under Part IIA of the Environmental Protection Act 1990 and therefore liable on the basis that one or more of its statutory predecessors caused the contamination. NGG sought a judicial review in the High Court of Justice where Mr. Justice Forbes ruled that they were liable for the costs of the decontamination. The ruling was considered a crucial issue by NGG as, if they were deemed liable in this particular instance, then they could be found liable in a substantial number, possibly thousands, of other cases involving former gasworks.
The Escambia Wood Treating Company (ETC) site is located at 3910 Palafox Highway, northeast of the intersection of Fairfield Drive in Pensacola, Florida, and is in a mixed industrial, commercial, and residential area. The site includes the 26-acre property of the former wood preserving facility and over 60 acres of nearby neighborhoods. The facility was in operation from 1942 until 1982, then abandoned by the owner in 1991. During its operation, ETC treated utility poles, foundation pilings, and lumber with creosote and pentachlorophenol. Production byproducts were dumped into on-site, unlined containment pits where they seeped into the surrounding soil and groundwater. Escambia Wood Treating Company
The Koppers Co., Inc. (KCI) Superfund Site is one of three Superfund sites in Oroville, California, along with Louisiana Pacific Sawmill and Western Pacific Railyard. The KCI Superfund Site is a 200-acre site which served as a wood treatment plant for 50 years. Wood was treated with many chemicals to prevent wood deterioration. The accumulation of these chemicals from spills, fires, and uses has caused this site to be contaminated with the hazardous waste material. Due to soil and groundwater contamination, the site was placed on the National Priorities List in 1984 for remedial action plans to clean up the site to protect surrounding residential areas concerning environmental and human health risks.
The Waste Disposal Inc. Superfund site is an oil-related contaminated site in the highly industrialized city of Santa Fe Springs in Los Angeles County, California. It is approximately 38 acres (15 ha), with St Paul's high school immediately adjacent to the northeast corner of the site. Approximately 15,000 residents of Santa Fe Springs obtain drinking water from wells within three miles (4.8 km) of the site.
Water in Arkansas is an important issue encompassing the conservation, protection, management, distribution and use of the water resource in the state. Arkansas contains a mixture of groundwater and surface water, with a variety of state and federal agencies responsible for the regulation of the water resource. In accordance with agency rules, state, and federal law, the state's water treatment facilities utilize engineering, chemistry, science and technology to treat raw water from the environment to potable water standards and distribute it through water mains to homes, farms, business and industrial customers. Following use, wastewater is collected in collection and conveyance systems, decentralized sewer systems or septic tanks and treated in accordance with regulations at publicly owned treatment works (POTWs) before being discharged to the environment.
Brook Industrial Park (BIP) is an industrial area occupying 4.5 acres of the Borough of Bound Brook, New Jersey, in the United States of America. It is located on the northern bank of the Raritan River. Industrial, chemical and pesticide operations began in 1971 and eventually lead to the contamination of groundwater and exposure of workers to harmful dioxins. Throughout 1980 to 1988 the United States Environmental Protection Agency (EPA) and the New Jersey Department of Environmental Protection (NJDEP) conducted studies to determine if there were any threats being posed on the workers, community or environment by the BIP companies in their disposal of processed and stored chemicals.