North Pest Clean
Central Denmark Region – the Midtjylland region (Regional authority)
Project manager: Morten BONDGAAR
Address: Skottenborg 26, DK – 8800 Viborg
Phone: +45 7841 1916, +45 7841 1966 (mobile)
WHEN: September 2010 – June 2014
WASTE MANAGEMENT HIERARCHY: Disposal (decontamination) TYPE OF INSTRUMENT: Voluntary and Awareness
WASTE STREAMS: Hazardous – Pesticides
North Pest Clean is a project which has proved that alkaline hydrolysis can be used as new technology for remediation of pesticide contaminated soil and groundwater.
The starting point was based on previous laboratory and small-scale field studies, which showed alkaline hydrolysis can be used to successfully degrade and remove the toxic chemicals from the soil. By establishing measurable stop-criteria and demonstrating the effectiveness of the new method, the project aimed to provide decision makers with crucial information that could allow them to make a science-based decision on how to progress with site remediation.
The project was carried out at the Danish contaminated site „Groyne 42” (situated in the western part of Denmark, on the beach facing the North Sea), which was used between 1950-1960 for the disposal of chemicals waste, implying thus high human health and environment risks. After that period, it remained heavily contaminated with approximately 260 tonnes of mainly organophosphorus pesticides.
Since 2006, the Denmark Central region and the Danish Environmental Protection Agency had conducted research into a novel treatment consisting of enclosure, in-situ alkaline hydrolysis, and pump-and-treat.
Under the project, a test site consisting of 3 test cells and 3 test pipes were constructed. In each of the 3 test cells separate technologies (acoustic vibration, recirculation and surfactant flushing) were implemented to enhance contact between caustic soda and the pesticides.
The efficiency of the in-situ (on the site) alkaline hydrolysis method and the performance of the enhancements were monitored throughout the project by analyzing water and soil samples and calculation of contaminant mass removal and degradation rates
1) Demonstrate, using large-scale pilot studies, that a novel remediation method based on in-situ alkaline hydrolysis is an effective technology for cleaning pesticide contaminated soil and groundwater;
2) Establish a basis for decision-making on full-scale site remediation;
3) Use the pilot studies to test the effectiveness of different „enhancement” technologies and to estimate the cost-effectiveness of scaling-up each technology to allow for full-scale site remediation;
4) Create awareness among authorities and environmental scientists in EU Member States about this novel remediation technology and its effectiveness in large-scale pilot studies;
5) Compare the remediation potential of this new method with risk assessment-based stop-criteria for the clean-up
The main resource the project has been based on the capacity of the project coordinator – the Department of Soil and Natural Resources in the Region of Midtjylland (Central Denmark Region), which is responsible for administering national legislation on soil contamination in the region.
North Pest Clean has been funded by the EU under the LIFE+ 2009 program, the Danish Environmental Protection Agency and the Central Denmark Region.
The accessed EU funds:
- Project reference LIFE09 ENV/DK/000368
- Duration 01.09.2010 – 30.06.2014
- Total budget 1,596,870.00 €
- EU contribution 798,000.00 €
Project location: Midtjylland (Central Denmark Region).
Project’s expected results were:
1) To remove 70-90% of the pesticides at the project site, using in-situ alkaline hydrolysis;
2) To measure the effect of enhancement methods on mass removal of contaminants;
3) To prepare a decision-basis report showing that full-scale remediation by using in-situ alkaline hydrolysis is cost-effective (remediation using traditional technologies was estimated to cost EUR 15-53 million, whereas remediation by in-situ alkaline hydrolysis had an estimated cost of EUR 6-9 million).
The efficiency of the method varied for the different pesticides at the test site. The method was most effective in removing malathion, methyl parathion and sulfotep. The main contaminant at „Groyne 42”, Ethylparathion, is the compound that has the lowest degradation rate.
After completion, the North Pest Clean project demonstrated that in-situ alkaline hydrolysis is a new cost-effective remediation technology that can be used in cleaning-up organo-phosphorous pesticides that contaminate soil and groundwater. The method has been proven to be a valid and useful one, as in-situ alkaline hydrolysis provided a solution that could be applied to remediate the entire large area of contamination used for the tests.
Also, the derived environmental effects of in-situ alkaline hydrolysis scored better that traditional excavation in the areas of acidification, ozone formation and global warming (CO2 emissions). It was also cost effective compared to other traditional remediation techniques -such as excavation and thermal remediation.
Urban metabolism relevance
During the years 1957-1962, Cheminova (chemicals manufacturing company) deposited waste from the production of pesticides in the sand dunes at „Groyne 42”, as it had permition from the Danish Government. Actually, the state itself used the site to deposit chemical waste in these years. The first excavation of contaminated soil took place in the 1970’ies.
In the following years, the local citizens and the authorities became aware that the dumpsite posed a considerable risk to the environment and the wildlife, after noticing dead fish and diseased birds.
The strong contamination with the parathionic substances recorded in the region determined the study of site.
In 1981, the Danish Environment Protection Agency (EPA) financed the excavation of contaminated soil down to the water table (groundwater). A quantity of 1.200 tons of toxic chemicals were removed. Unfortunately, 200-300 tons of toxic chemicals were still founded under the water table.
After realizing, in 2000, that chemical seepage from the dumpsite was still posing a risk to the environment and wildlife, the former Ringkjøbing County and the Danish EPA agreed to share the costs of encapsulating the contaminated area.
The contaminated site covered 20.000 sqm. and 10 meters deep and has been completely encapsulated in 2006, the area being covered by a membrane and the water table kept lower than outside the site, to prevent seepage. The iron sheet piling used is guaranteed to be functional for 15 years and is expected to last even longer.
The above-mentioned figures are very relevant in proving that deposited polluted waste has a big impact on the environment and people’s health and, without its treating and neutralizing, the effects can be devastating, affecting the soil, water and all biosystems from the area.
In situ alkaline hydrolysis has not previously been used as a technology to remediate soil and groundwater contaminated with organophosphorus pesticides.
Since 2005, the Region Midtjylland and the Danish EPA have been developing a remediation technique based on encapsulation of the contaminated soil, followed by degradation of toxic substances by adding strong alkaline liquid.
Lab experiments and experiments in small scale on site have shown that alkaline liquid is able to degrade toxic substances in the soil matrix effectively.
The metabolites are water-soluble and can be pumped to the surface for further treatment.
Project results confirmed that the new technology, as a new low-cost method, could encourage more remediation of pesticide-contaminated sites that would otherwise have been left unattended.
Engaged participatory processes
To maximize the participatory process, different strategy for dissemination has been used to target groups which consisted in:
1) local stakeholders
3) national professionals
4) international professionals etc.
Also, different media has been applied (e.g. pamphlets, presentations, workshops, radio, videos).
The after-life strategy has been similar to the project strategy.
Also, as a continuation of project, numerous activities have been planned to be carried out
during the years following project completion, such as:
– Maintaining and updating the project web-page with the newest information.
– The site („Groyne 42”) is part of a „Danish Soil Tour” and visitors can be introduced to the LIFE project. Also, the site is available for visits from foreign delegations at request.
– Regularly dissemination activities at international and national workshops and conferences in the years following the project completion.
– Presentation of project results to Environmental government officials in Shanghai and Chengdu (China), with the purpose of sharing knowledge on the newly-found method „In situ alkaline hydrolysis”.
Sustainability and replicability
The sustainability assessment tool applied in North Pest Clean project is a tool which compares the sustainability of different remediation methods. It is a multi-criteria model, which includes five main criteria:
The tool/approach involved close collaboration with key stakeholders in every case. This approach for sustainability assessment has been implemented in the regional procedures to improve the basis for selecting the most „sustainable” remedy.
Also, this new technology holds a high transferability potential and is ready to be applied by EU Member States, its implementation being able to facilitate a decrease in the cost of soil restoration and improve soil restoration and environmental protection.
The project is based on the scientific literature, which explains that alkaline hydrolysis can be used to degrade organo-phosphorous insecticides such as ethyl-parathion to less toxic and water-soluble metabolites.
The method has been used for many years by agrochemical companies producing organophosphorus pesticides to neutralize the compounds upon accidental spill, but also as a pre-treatment of wastewater containing organophosphates before it is led to the biological wastewater treatment plant.
Waste, Resources, Innovation.
The cost of soil remediation is the most frequent reason for not taking action. The approach of this project makes it possible to decontaminate soil containing high concentrations of pesticides at much lower costs than assumed previously.
Another challenge and also a driver for this project was that, in 2006, the European Commission adopted the Soil Thematic Strategy (COM (2006) and a proposal for a Soil Framework Directive (COM (2006). In the Soil Framework Directive, it was proposed that Member States should establish an inventory of contaminated sites in Europe and, over time, ensure remediation of these sites, which may pose a risk to human health or the environment.
For more information, please contact the implementing body.
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