Technology Programme for Soil and Groundwater
Contamination 2000

5. Project proposals for 2000-2001

5.1 Objectives of field projects
5.2 Technologies to be tested
5.3 Field projects with high priority for 2000 - 2001
5.3.1 Chlorinated solvents
5.3.2 Oil/petrol
5.3.3 MTBE
5.3.4 PAH/tar contamination and combined contamination
5.3.5 Gas from landfills
5.4 Desk studies for 2000-2001
5.4.1 Computer models
5.4.2 Assessment of alternative on-site methods for remediation of air and water
5.4.3 Financial assessments of remediation of contaminated soil and groundwater
5.4.4 Assessment of the amount of soil remediated at plants
5.4.5 Assessment of contamination effects on indoor climates
5.4.6 Determination of concentrations at source in mobile pore water in the unsaturated zone
5.4.7 Determining the horizontal longitudinal dispersivity in lime aquifers which are representative for Danish conditions
5.4.8 Preparation of hydrogeological mapping requirements with a view to determining the degradation rate locally.
5.4.9 New methods for characterising contaminated sites
5.5 Other projects for 2000 - 2001

The overall objective of the Technology Programme is to create a basis for more efficient (in terms of both environmental impact and cost) remediation of contaminated sites, and to test new and recent remediation technologies.

Figure 1 shows an outline of a traditional sequence of events for a remedial project. The scope of the work initiated under the auspices of the Technology Programme depends on the stage which surveys and remedial measures have reached for each specific site.

5.1 Objectives of field projects

The objective of the field projects is to test and provide documentation for methods, and in particular to assess whether the preconditions set out are being met. When testing these methods, specific requirements must be stipulated for preliminary surveys and preliminary tests to dimension and design plant. On the basis of tests, prognoses are prepared for remediation work, especially with regard to duration and remediation levels. Before the remedial measures are initiated, a process of regular operation control and final documentation of the remediation must be described in detail. In addition to this, environmental assessments and financial assessments of the costs and benefits involved in individual techniques are carried out. Appendix C features a paradigm for a list of contents and Appendix D features a budget for a technology project.

The results of the field projects, along with studies of the literature available, are issued as general documents (reports, guidelines, etc.) on the use of the methods under Danish conditions.

The results of the Technology Programme are continuously presented and communicated by preparing publications which will also appear on the Danish EPA homepage. Moreover, the programme and projects will be presented on a regular basis at various meetings such as ATV meetings (ATV - the Danish Academy of Technical Sciences) and meetings at the Information Center on Contaminated Sites, IDA - the Society of Danish Engineers and universities.

Figure 1
Process description

5.2 Technologies to be tested

Below is a list of the technologies to be tested within the next five years. This list is subject to adjustment in the event of more detailed surveys (Danish or foreign) showing that testing of a specific method would not be relevant.

Other field projects:

	Testing of alternative examination methods, e.g. field analyses, boring methods, and equipment for sample extraction.
	Assessment of examination methods for mapping.

5.3 Field projects with high priority for 2000 - 2001

Within each area of special interest, the projects for 2000-2001 have been listed in the following. The number of projects which can be initiated depends on the scope of the individual projects and the cost. Mapped sites are preferred for testing of the technologies.

5.3.1 Chlorinated solvents

· Thermically assisted remediation (development stage 3)

Thermically assisted remediation involves heating the soil, which causes the volatile contaminants to be more effectively and efficiently eliminated. In the USA, experiments have been carried out on heating the soil by means of five different methods:

- injection of hot air and steam,

- injection of hot water,

- electric heating by means of electrodes and low-frequency electricity,

- heating by means of radio waves and microwaves via aerials, and

- direct thermic conduction into soil by means of a heating blanket or a heating well. The assessment is that it is relevant carry out further testing of the methods directed against contamination in clay strata and beneath the groundwater level. Plans have been made to initiate one or two additional field projects on selected methods.

· Dual-phase extraction (development stage 3)

Dual-phase extraction is a remediation method which is used in less permeable strata, where more usual methods such as soil-vapour extraction and/or air sparging cannot be used. Dual-phase extraction involves establishing a powerful vacuum in the remedial boring, so that both pore air and pore water/groundwater is extracted simultaneously from the contaminated volume of soil. The extracted air/water is stripped and remediated in a plant. A field project is expected to be initiated.

· Modified stripping methods, e.g. well-vapour extraction
(development stage 3)

These modified methods involve combining the recirculation of groundwater with stripping and thus combining air sparging with soil-vapour extraction in the same borings (e.g. in-well stripping or bioslurping). In the USA, various types of modified methods exist. One or two field projects using these methods against chlorinated solvents are planned.

· Fracturing (development stage 2 or 3)

One or two projects are expected to be initiated on the basis of a desk study describing various fracturing methods. Fracturing involves creating artificial fissuring of low-permeable strata, e.g. by injecting a fluid or air into the bottom of a boring at high pressure.

· Chemical remediation by addition of hydrogen
(development stage 3)

It is to be assessed whether it would be relevant to initiate a project on chemical remediation by addition of hydrogen. The method involves accelerating the degradation of chlorinated solvents by establishing anaerobic conditions. This changes the redox conditions, so that the potential for degradation of PCE and TCE is increased. It may be relevant to assess whether this method is effective against deep contamination of chlorinated solvents.

· Optimising remedial pumping (development stage 3)

Efforts are to made to either optimise operation of remedial pumping at a site, or to test alternative remediation methods.

· Phyto remediation (development stage 1 or 2)

A phyto-remediation project for soil and groundwater contaminated by chlorinated solvents may be carried out.

5.3.2 Oil/petrol

· Modified stripping methods, e.g. well-vapour extraction
(development stage 3)

These modified methods involve combining the recirculation of groundwater with stripping and thus combining air sparging with soil-vapour extraction in the same borings (e.g. in-well stripping or bioslurping). In the USA, various types of modified methods exist. One or two field projects using these methods against contamination from oil or petrol are planned.

· Accelerated/forced degradation (development stage 3 or 4 )

Tests carried out in the USA show that degradation of oil-/petrol contamination can be accelerated/forced by addition of oxygen, e.g. as ORC. One or two field projects using these methods against contamination of oil or petrol contamination and possibly MTBE contamination are planned.

· Biological filters (development stage 2 or 3)

Testing is to carried out on various biofilters for remediation of air and water contaminated by oil or petrol. These tests are to be compared to carbon remediation.

· Modified stripping methods, e.g. well-vapour extraction
(development stage 2 or 3)

These modified methods involve combining the recirculation of groundwater with stripping and thus combining air sparging with soil-vapour extraction in the same borings (e.g. in-well stripping or bioslurping). In the USA, various types of modified methods exist. A field project using these methods against contamination from petrol or MTBE is planned.

· Degradation of MTBE by means of bacteria
(development stage 1, 2 or 3)

In the USA, a culture of bacteria capable of degrading groundwater contaminated by MTBE has been isolated. Preliminary Danish tests show that there is a potential for using this culture of bacteria in an on-site remediation filter. Plans have been made for carrying out one or two field projects where this method is compared with other remediation methods.

· Remediation of MTBE by means of filtering
(development stage 1, 2 or 3)

The desk study "Remediation techniques for groundwater contaminated by MTBE" recommends testing of various filter types for on site remediation of contaminated groundwater. One or two field projects are to test and assess various filters (carbon filters, addition of ozone combined with biological filtering, etc. ).

· Biological remediation of MTBE (development stage 2 or 3)

The latest results from USA show good effects from passive remediation of groundwater contaminated by MTBE by letting the contaminated water pass through an oxygen barrier in the groundwater aquifer. One or two field projects have been planned.

5.3.4 PAH/tar contamination and combined contamination

· Soil contaminated by tar used in noise-deflecting barriers, etc.
(development stage 3)

One or more field projects are to provide documentation for the risk of spreading contamination when soil contaminated by tar is used to build noise-deflecting barriers and roads.

· Remediation of combined contamination,
i.e. in a thermic processing plant

Plans have been made to document how combined contamination is remediated, e.g. in thermic processing plants and other existing soil-remediation plants. Special focus will be placed on the issue of the levels of remediation which can be achieved and on the end products.

· Natural attenuation of PAHs in water
(development stage 3)

A field project is to survey and document the natural attenuation processes for PAHs. This includes formation of attenuation products.

· Risk of gas from landfills

Depending on the result of an ongoing desk study which carries out risk assessment of explosion hazards from gas in landfills, it may be relevant to carry out a field project for further elucidation and clarification.

The following desk studies are planned.

Computer models are to be set up and tested for various stripping methods. An English version of the Danish EPA software "JAGG" is to be prepared.

Various methods are to be described and assessed in order to reduce operating costs for remediation of contaminated air and groundwater. One or two field projects are expected to be initiated on the basis of the results of this project.

5.4.3 Financial assessments of remediation of contaminated soil and groundwater

A paradigm for calculating the financial costs involved in establishing a remediation project is to be prepared. Key figures are to be calculated for individual techniques on the basis of specific projects. The financial costs for the various techniques are to be compared.

5.4.4 Assessment of the amount of soil remediated at plants

Examinations are to be carried out of how much soil is sent to be remediated and how big a proportion of this soil is remediated so that it can be used freely and how much soil is subsequently deposited. This survey is to extend to various contaminants.

5.4.5 Assessment of contamination effects on indoor climates

Coherent and interconnected data is to be collected for recording volatile contaminants underneath floors and in buildings with a view to carrying out an assessment of how floor constructions reduce contamination concentrations.

5.4.6 Determination of concentrations at source in mobile pore water in the unsaturated zone

This project is to result in guidelines on how concentrations at source can be determined, thus making risk assessment more accurate.

5.4.7 Determining the horizontal longitudinal dispersivity in lime aquifers which are representative for Danish conditions

5.4.8 Preparation of hydrogeological mapping requirements with a view to determining the degradation rate locally.

5.4.9 New methods for characterising contaminated sites

There is a need for methods and techniques which can characterise and describe contamination in a better and more cost-effective way. This will be carried out when there is a sufficient number of methods/techniques which can be described and possibly field tested.

5.5 Other projects for 2000 - 2001

The following other projects are planned for the soil-contamination area.

	Standardisation work 'ISO' under the auspices of the EU.
	Assessment of mercury contamination of soil in Denmark.
	Evaluation of remediation carried out under the Danish Petroleum Industry Association for Remediation of Retail Sites Programme.
	Method testing of a PAH analysis method.
	Standardisation of method for determining total carbon-hydrogen contents, including BTEX contents, in water.
	Assessment of PAH / METABOLITTER. A survey may be carried out of whether PAH / METABOLLITER, which appear in connection with degradation of PAHs, present a problem in terms of the environment and human health.
	Data model for contaminated soil. A data model (a logical description which operates independently of specific systems) for data on soil contamination is to be prepared.
	Continuation of projects on absorption of contaminant compounds in fruit and vegetables.
	Health-based criteria for soil and groundwater.
	Survey on bioavailability for contaminants in soil.
	Systematisation of data on diffuse contamination, phase 2.
	Evaluation of the Technology Programme.
	Information. Preparation of a leaflet.