Remediation technologies are many and varied. The more traditional remediation approach—used almost exclusively on contaminated sites from 1970 to 1990—consists largely of excavation and deposition—through thermal desorption—and pumped and treated groundwater.

Excavation processes can be as simple as hauling contaminated soil to a regulated landfill, but may also involve aerating the material in the case of volatile contaminants. If the pollution affects a river or bay, then excavation of the bay bottom or other clays will need to be carried out.

Pump and treat involves pumping contaminated groundwater out with the use of a submersible or vacuum pump and allowing the extracted groundwater to be purified in a slow process through a series of containers containing materials designed to absorb contaminants from the groundwater. For oil impacted sites, this material is usually activated carbon in granular form. Chemical reagents such as flocculants and sand filters can also be used to reduce groundwater contamination.

Depending on the geology and soil type, pump and treat can be a good method for rapid reduction of high contaminant concentrations. It is more difficult to achieve concentrations low enough to meet remediation standards, due to the balance of absorption and desorption processes in the soil.

New in situ oxidation technologies have become popular for the remediation of a wide range of soil and groundwater contaminants. Remediation by chemical oxidation includes the injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate or persulfates. Another use is in the elimination of contaminants in soils impacted with hydrocarbons.

Oxygen gas or ambient air can also be injected as a gentler approach. A disadvantage of this approach is the possibility of less destruction of contaminants by natural attenuation if bacteria that normally live in soil prefer a reducing environment. Injection of gases into groundwater can also cause contamination to spread more rapidly than normal depending on the hydrogeology of the site.

Soil vapor extraction and oxidation (or incineration) can also be an effective remediation technology. This approach is somewhat controversial due to the risks of dioxins released into the atmosphere through exhaust gases. Controlled high-temperature incineration with exhaust gas filtration, however, should not pose any risk. Two different technologies can be employed to oxidize contaminants from an extracted steam stream.

Thermal oxidation uses a system that acts as an oven and maintains temperature ranges from 730 °C to 815 °C. Catalytic oxidation uses a catalyst as an aid to facilitate a low oxidation temperature. This system usually maintains temperatures in a range of 315 °C to 430 °C.

Thermal oxidation is more useful for high concentrations of steam influent streams—requiring less use of natural gas—than catalytic oxidation. For low concentration levels, the extracted vapors can also be treated by allowing them to flow through a series of vessels designed for vapor flow. These vessels contain materials designed to absorb contaminants from the vapor. The absorbent is usually activated carbon in granular form.

The treatment of environmental problems with biological means is known as bioremediation and the specific use of plants, for example through the use of phytoremediation.

Bioremediation is sometimes used in conjunction with a “pump and treat” system. In bioremediation that also occurs naturally or especially bread bacteria is used to consume contaminants from extracted groundwater. This is sometimes known as a bio-gac system.

Sometimes groundwater is recycled to allow a continuous flow of water by enhanced growth of the bacteria population.

Occasionally the bacteria can increase in such a way that it affects filtration and pumping. The vessels must then be partially drained. Care must be taken to ensure that an acute change in groundwater chemistry will kill the bacteria—such as an unexpected change in pH.

Dual-phase extraction uses a soil vapor extraction system that produces a high vacuum resulting in the extraction of both contaminated vapors and the limited amount of groundwater contaminants. This method is somewhat inefficient due to the large amounts of energy required to pull water using a vacuum compared to pushing water with a submersible pump.

In preparation for any significant remediation, there must be extensive community consultation. The proponent must both present information and seek information from the community. The proponent needs to learn about future sensitivity such as child care, schools, hospitals and playgrounds, as well as community concerns and information of interest. The consultation must be open, in a basic group so that each member of the community is informed about topics that are not addressed individually. An independent president acceptable to both the proponent and the community must be hired.

It will include a few minutes of meetings with questions and answers. And copies of the proponent's presentations must be available both online and in a local bookstore—even a school one—or community center.

It is the risk that a recipient—typically a human being who lives nearby—will face in a remediation project.

The use of incremental health risk is based on carcinogenic and other effects—e.g., mutagenic, teratogenic—and often includes value judgments about the projected rates of increase in cancer. In some jurisdictions this is 1 in 1,000,000 but in others the acceptable rate of increase is 1 in 100,000. A relatively small incremental risk for a single project is not very comfortable if the area already has a relatively high risk from other operations such as incinerators or other emissions, or if other projects exist at the same time causing a greater cumulative risk or an unacceptably high total risk. An analogy commonly used by remediators is to compare the risk of remediation in nearby residents to the risks of death in car accidents or tobacco smoking.

They are established based on the levels of dust, noise, odors, air emissions, groundwater and sewer discharges through which the water goes, of all chemicals or chemicals concerned such as those produced through the remediation by processing of contaminants. These are compared against both the natural bottom level and the standards of nearby areas and against the standards of recent remediations. Just because the emission is sent from the area designated as industrial, does not mean that a nearby residential area will allow any excess over residential standards.

Monitoring for compliance against each standard should ensure that surpluses are detected and reported by both authorities and the local community.

Enforcement is necessary to ensure that significant or continued failures will result in fines or even prison sentences for the polluter.

The penalties must be significant or else the fines will be considered a normal expense of doing business. Compliance with the rules should be cheaper than continuous failure to comply with them.

There must be an assessment for the risks of operations, transportation of contaminated material, disposal of waste, which may be contaminated, including workers' clothing, and a formal emergency plan that must be developed. Each worker and visitor who enters the site must have a safe and personalized induction about their involvement with the site.

Relocation is often met with resistance from the community and local government due to the adverse impacts on the locality of remediation and new development. The main impacts during remediation, noise, dust, odors and increased health risks. There will then be an impact on local traffic, schools, playing fields and other public facilities for the majority of the local population.

What was done in Homebush Bay, New South Wales, Australia, is an example of complete relocation, remediation and redevelopment, carried out by a state government, opposed by a local government and its surrounding communities. Dioxins from the American company Union Carbide, used in the production of a currently banned pesticide, 2,4,5-trichlorophenoxyacetic acid, and Agent Orange, a herbicide and defoliant used by the United States Armed Forces, had contaminated Homebush Bay. After the government's intervention, the chemical production plants gave way to residential development and the sale and development of offices. [1] In fact, during the 2000 Sydney Olympics, some of the main events of the event were held around Homebush Bay.

However, the remediation of contaminated Homebush Bay land also generated much controversy among local activists. Their opposition can be followed through sources on the Internet:

• Numerous investigations and reports from Australian and international consultants.

• A parliamentary inquiry by the Upper House of the parliament of New South Wales, a state of Australia.

• Two investigation commissions, one for each of the main carbon dioxide pollution sites, both contaminated by the operations of the Union Carbide company.

• Resolutions by relevant local government bodies.

• Campaigns by local residents' groups, Greenpeace Australia, the NSW Nature Conservation Council, and West Green Comprehensive Environmental Impact, which published studies in digital format and available on CD from Planning NSW.

Despite the success of the Homebush Bay remediation, fishing in the area remains completely prohibited.[4]​ [5]​ Commercial fishing is also prohibited in the entire area west of the Gladesville Bridge. The complete fishing ban should be extended to the entire Parramatta River west of Homebush Bay and at least as far as Ryde Bridge.

In the United States there has been a mechanism to tax polluting industries and form a foundation to remediate abandoned sites, or to litigate forcing corporations to remediate their contaminated sites. Other countries have other mechanisms and commonly sites are rezoned for "higher" uses, such as high-density housing, to give the land a higher value, so that after deducting clearance costs, there is still an incentive for a developer to purchase the land, clear it, redevelop it and sell it, often as apartments (housing units).

Remediation technologies are many and varied. The more traditional remediation approach—used almost exclusively on contaminated sites from 1970 to 1990—consists largely of excavation and deposition—through thermal desorption—and pumped and treated groundwater.

Excavation processes can be as simple as hauling contaminated soil to a regulated landfill, but may also involve aerating the material in the case of volatile contaminants. If the pollution affects a river or bay, then excavation of the bay bottom or other clays will need to be carried out.

Pump and treat involves pumping contaminated groundwater out with the use of a submersible or vacuum pump and allowing the extracted groundwater to be purified in a slow process through a series of containers containing materials designed to absorb contaminants from the groundwater. For oil impacted sites, this material is usually activated carbon in granular form. Chemical reagents such as flocculants and sand filters can also be used to reduce groundwater contamination.

Depending on the geology and soil type, pump and treat can be a good method for rapid reduction of high contaminant concentrations. It is more difficult to achieve concentrations low enough to meet remediation standards, due to the balance of absorption and desorption processes in the soil.

New in situ oxidation technologies have become popular for the remediation of a wide range of soil and groundwater contaminants. Remediation by chemical oxidation includes the injection of strong oxidants such as hydrogen peroxide, ozone gas, potassium permanganate or persulfates. Another use is in the elimination of contaminants in soils impacted with hydrocarbons.

Oxygen gas or ambient air can also be injected as a gentler approach. A disadvantage of this approach is the possibility of less destruction of contaminants by natural attenuation if bacteria that normally live in soil prefer a reducing environment. Injection of gases into groundwater can also cause contamination to spread more rapidly than normal depending on the hydrogeology of the site.

Soil vapor extraction and oxidation (or incineration) can also be an effective remediation technology. This approach is somewhat controversial due to the risks of dioxins released into the atmosphere through exhaust gases. Controlled high-temperature incineration with exhaust gas filtration, however, should not pose any risk. Two different technologies can be employed to oxidize contaminants from an extracted steam stream.

Thermal oxidation uses a system that acts as an oven and maintains temperature ranges from 730 °C to 815 °C. Catalytic oxidation uses a catalyst as an aid to facilitate a low oxidation temperature. This system usually maintains temperatures in a range of 315 °C to 430 °C.

Thermal oxidation is more useful for high concentrations of steam influent streams—requiring less use of natural gas—than catalytic oxidation. For low concentration levels, the extracted vapors can also be treated by allowing them to flow through a series of vessels designed for vapor flow. These vessels contain materials designed to absorb contaminants from the vapor. The absorbent is usually activated carbon in granular form.

The treatment of environmental problems with biological means is known as bioremediation and the specific use of plants, for example through the use of phytoremediation.

Bioremediation is sometimes used in conjunction with a “pump and treat” system. In bioremediation that also occurs naturally or especially bread bacteria is used to consume contaminants from extracted groundwater. This is sometimes known as a bio-gac system.

Sometimes groundwater is recycled to allow a continuous flow of water by enhanced growth of the bacteria population.

Occasionally the bacteria can increase in such a way that it affects filtration and pumping. The vessels must then be partially drained. Care must be taken to ensure that an acute change in groundwater chemistry will kill the bacteria—such as an unexpected change in pH.

Dual-phase extraction uses a soil vapor extraction system that produces a high vacuum resulting in the extraction of both contaminated vapors and the limited amount of groundwater contaminants. This method is somewhat inefficient due to the large amounts of energy required to pull water using a vacuum compared to pushing water with a submersible pump.

In preparation for any significant remediation, there must be extensive community consultation. The proponent must both present information and seek information from the community. The proponent needs to learn about future sensitivity such as child care, schools, hospitals and playgrounds, as well as community concerns and information of interest. The consultation must be open, in a basic group so that each member of the community is informed about topics that are not addressed individually. An independent president acceptable to both the proponent and the community must be hired.

It will include a few minutes of meetings with questions and answers. And copies of the proponent's presentations must be available both online and in a local bookstore—even a school one—or community center.

It is the risk that a recipient—typically a human being who lives nearby—will face in a remediation project.

The use of incremental health risk is based on carcinogenic and other effects—e.g., mutagenic, teratogenic—and often includes value judgments about the projected rates of increase in cancer. In some jurisdictions this is 1 in 1,000,000 but in others the acceptable rate of increase is 1 in 100,000. A relatively small incremental risk for a single project is not very comfortable if the area already has a relatively high risk from other operations such as incinerators or other emissions, or if other projects exist at the same time causing a greater cumulative risk or an unacceptably high total risk. An analogy commonly used by remediators is to compare the risk of remediation in nearby residents to the risks of death in car accidents or tobacco smoking.

They are established based on the levels of dust, noise, odors, air emissions, groundwater and sewer discharges through which the water goes, of all chemicals or chemicals concerned such as those produced through the remediation by processing of contaminants. These are compared against both the natural bottom level and the standards of nearby areas and against the standards of recent remediations. Just because the emission is sent from the area designated as industrial, does not mean that a nearby residential area will allow any excess over residential standards.

Monitoring for compliance against each standard should ensure that surpluses are detected and reported by both authorities and the local community.

Enforcement is necessary to ensure that significant or continued failures will result in fines or even prison sentences for the polluter.

The penalties must be significant or else the fines will be considered a normal expense of doing business. Compliance with the rules should be cheaper than continuous failure to comply with them.

There must be an assessment for the risks of operations, transportation of contaminated material, disposal of waste, which may be contaminated, including workers' clothing, and a formal emergency plan that must be developed. Each worker and visitor who enters the site must have a safe and personalized induction about their involvement with the site.

Relocation is often met with resistance from the community and local government due to the adverse impacts on the locality of remediation and new development. The main impacts during remediation, noise, dust, odors and increased health risks. There will then be an impact on local traffic, schools, playing fields and other public facilities for the majority of the local population.

What was done in Homebush Bay, New South Wales, Australia, is an example of complete relocation, remediation and redevelopment, carried out by a state government, opposed by a local government and its surrounding communities. Dioxins from the American company Union Carbide, used in the production of a currently banned pesticide, 2,4,5-trichlorophenoxyacetic acid, and Agent Orange, a herbicide and defoliant used by the United States Armed Forces, had contaminated Homebush Bay. After the government's intervention, the chemical production plants gave way to residential development and the sale and development of offices. [1] In fact, during the 2000 Sydney Olympics, some of the main events of the event were held around Homebush Bay.

However, the remediation of contaminated Homebush Bay land also generated much controversy among local activists. Their opposition can be followed through sources on the Internet:

• Numerous investigations and reports from Australian and international consultants.

• A parliamentary inquiry by the Upper House of the parliament of New South Wales, a state of Australia.

• Two investigation commissions, one for each of the main carbon dioxide pollution sites, both contaminated by the operations of the Union Carbide company.

• Resolutions by relevant local government bodies.

• Campaigns by local residents' groups, Greenpeace Australia, the NSW Nature Conservation Council, and West Green Comprehensive Environmental Impact, which published studies in digital format and available on CD from Planning NSW.

Despite the success of the Homebush Bay remediation, fishing in the area remains completely prohibited.[4]​ [5]​ Commercial fishing is also prohibited in the entire area west of the Gladesville Bridge. The complete fishing ban should be extended to the entire Parramatta River west of Homebush Bay and at least as far as Ryde Bridge.